Dispelling The Myths: The Importance Of Flushing Your Plants Before Harvest

plant flushing

The following blog on plant flushing is a guest post from Advanced Nutrients. The views, thoughts, and opinions expressed in the text belong solely to the author, and not necessarily to the CannaCon organization, employees or other related individuals.

Within the world of cultivation, there seems to be debate over the topic of plant flushing. Opponents of the technique believe that flushing plants prior to harvest will rob them of vital nutrients — an obviously bad idea. On the other side of the divide, advocates proclaim that flushing frees the plants of excess nutrients and contaminants and leads to an overall higher-quality product.

In this article, we’ll explore the truth about flushing: Precisely what it is, why it’s so important for growers to flush their plants, and the best way to go about flushing for maximum benefit.


What Is Flushing And Who Should Do It?

Before we get into the reasons why flushing your plants is so important, we need to understand exactly what it is. Flushing involves watering your plants without any added nutrients for a period of time — anywhere from a day or two to a week or more, depending on your growing medium — prior to harvesting. The purpose of this is to allow the plants time to use up the nutrients that have already built up within them, thereby lessening the overall nutrient and contaminant load of the final product.

We recommend flushing for growers of all types, whether hydro, coco coir or soil — though the time period for flushing will vary, depending on the medium.


The Importance Of Flushing

Though some in the industry have argued otherwise, the importance of flushing your plants has been affirmed by the vast majority of serious growers. Most experienced cultivators have tried not flushing before harvest, which has caused them to experience first-hand the glaring difference in quality of the yield.You see, during the growing cycle, your plants store excess amounts of nutrients, salts and other compounds. If you don’t allow the plants a chance to dispose of these surplus compounds by flushing them before harvest, your final product will be much harsher and more bitter tasting. Failing to flush can also cause your product to suffer from other negative side effects, such as black ash and an unpleasant chemical taste and smell.

The truth is, not flushing nutrients before harvest can seriously compromise the quality of your high-value crops.


To Flush Or Not To Flush: Examining The Arguments For And Against

Despite the overwhelming majority of growers who understand the importance of flushing and have verified its benefits through their own practice, there are some who argue against it.

The anti-flushers make a few bold claims, including:

  1. Robbing plants of nutrients at any stage of the grow cycle is counterproductive and does not benefit growth in any way.
  2. Once nutrients are absorbed into the plant tissues, they are there permanently. The plant cannot expel them or use them up simply by denying it more nutrients.
  3. If flushing was in fact a beneficial practice, then plants grown in hydro would always taste better than plants grown in soil because soil cannot be effectively flushed.
  4. Withholding nutrients causes stress to the plants, which impedes growth rather than encouraging it.
  5. Flushing plants is “pseudoscience” that has not been supported or backed by any legitimate scientific studies.

Let’s address these anti-flushing arguments one by one.

  1. Flushing your plants does not involve robbing them off nutrients. On the contrary, it allows your plants the chance to use the excess nutrients they have accumulated throughout the grow cycle. When you feed your crops full nutrient loads right up until the time of harvest, they retain an overabundance of compounds that affect the quality of the final product — including its taste, smell and overall smoothness.It’s also important to note that the main purpose behind flushing is not to encourage substantial new growth — although, flushing can cause your crop’s floral blooms to swell, since plants are not expelling all their energy on nutrient uptake.
  2. Any grower who has experienced nutrient burn knows the argument that plants cannot expel excess nutrients holds no weight. Ask any seasoned cultivator how to fix nutrient burn and they will tell you: You need to flush your plants and allow them time to use up the excess nutrients.The same logic applies to pre-harvest flushing. You’re giving your plants just enough time to use up surplus nutrients, salts and other compounds.
  3. The argument that soil can’t be effectively flushed is simply illogical and just plain wrong. Plants grown in soil can be flushed — it just takes a longer period of time than flushing plants grown in hydro or coco.
  4. It’s true that withholding nutrients places stress on plants and causes them to increase defense compounds. However, in certain plants, the primary defense compounds are actually the most desirable constituents, so flushing before harvest can significantly increase the value of the final product.
  5. At Advanced Nutrients, we employ the largest team of Ph.D. botanists, microbiologists, entomologists, hormone specialists and organic chemists in the industry. These scientists are dedicated solely to studying cultivation best practices and are constantly conducting laboratory research. The notion that plant flushing is “pseudoscience” is simply absurd.


The Truth About Flushing

Flushing plants before harvest is indeed a beneficial practice. However, there is a right way and a wrong way to go about it. In truth, the anti-flushers make a valid point when they say that it can rob your plants of nutrients — IF you are flushing with just plain water.The fact is, flushing with plain water can cause your plants to lose some floral growth and resin percentages. This is why it’s critical that you use a quality flushing agent that is designed specifically for the type of plants you grow.

When it comes to a flushing agent, you want to be sure to use one that contains a range of chelates. Chelates are organic compounds that can bind with other chemicals and substances. During the flushing process, these chelates will attach themselves to the excess nutrients, salts and other compounds in your plants and force them out.

At the same time, your plants utilize the stored nutrients they need during these last few days and hours prior to harvest. A high-quality flushing agent will provide your plants the support they need through this process, along with assisting them in purging the excess compounds that you don’t want in your final product.


Timing Is Key: When To Flush Your Plants

Along with using the right flushing agent, you need to ensure you’re flushing at the right time in order to reap the maximum benefits of flushing. Use the following as guidelines for flushing prior to harvest:

  • If you’re growing in soil, begin flushing between one and two weeks before harvest.
  • If you’re growing in coco, flush your plants for up to one week prior to harvest.
  • If you’re growing in hydro, your plants only need to be flushed for one to two days.

Of course, you’ll need to monitor your crops closely during the flushing process to ensure they don’t turn too yellow. Adjust your flushing times as necessary to find the ideal time for your plants.

To learn more about cultivation and nutrients visits  https://www.advancednutrients.com/articles


  1. Anthony on December 7, 2018 at 8:32 am

    my northernlights x big bud is going on 11 weeks cloudy trycomes with some clear trycomes new bud tip growth all over bud sites do i need to chop or wait 1 more week this train is 60 day to harvest not sure what to do

    • CB on April 14, 2019 at 8:48 pm

      Ia m having the same deal going on with mine. 11 weeks and still cloudy and clear. So I started taking the top ones in stages and I will choo the lower ones later to see what they do.. I will say the buds are sticky as he’ll that I already chop. They are curing now. If you figure yours out let us all know. I am growing under a 600w hps in ff soil. And ff nutes. With mammoth p.

      • Konrad on July 21, 2020 at 5:13 pm

        You should harvest when your tricombs are 70-80% white the final turn will happen during drying process.

        • Matt in midcoast Maine on October 8, 2021 at 11:20 am

          This year I decided to flush with 5 teaspoons of mango monster energy drink per gal of water…there in the ground no pots. People have questioned, to say the least what I’m doing…God only knows what response I’ll get from you growers out there…but let’s hear it…!

        • Toby on November 27, 2021 at 4:15 pm

          Did you mean to say 70-80% red lol??

          • Matt on December 17, 2022 at 7:39 am

            Trichomes 70-80% white, so 20-30% Amber. When the trichomes go amber the thc is beginning to degrade. You may be confusing the trichomes with pistils which should be about 60% red. But you should go on pistils alone because the plant will continue to make new pistils. You want to look at the trichomes on the flower.

      • Scott L on August 4, 2022 at 10:09 am

        Today marks the 10th week of my white widow Autoflowers and I started to flush them for a couple days last week until I noticed what seem to be Nutrient deficiency like crazy all my leaves around Bud sites have brown spots everywhere so I gave them a little bit of nutrients again and some cal mag because it looks like calcium deficiency for sure if not more deficiencies on top of that i’m giving them a little bit of big bloom hoping to stop any further damage I want to flush but I’m worried I will drastically decrease my yield

    • Stewster on April 16, 2019 at 12:37 pm

      If you’re in soil, start your flush. Flushing your plants (Soil) for a week or so will still allow your trichomes to mature.

      • Bee deezle on January 24, 2020 at 9:47 pm

        Flushing is BULLSCHIFF and so is the darkness before harvest nonsense…..I’ve tried experiments with and with pout and my friends actually preferred 5(3 non flushed buds and the darkness before harvest is a load of bologna too

        • Trev on February 11, 2020 at 10:19 am

          Flushing is not bull. If you don’t see better results with flushed plants vs unflushed u ain’t flushing right. I took unflushed buds from a plant, dried and cured then flushed the rest (to under 50ppm run off day 1 of flush) then feed 0ppm water for 1 week(in coco) the flushed buds make a white ash and u can barely feel the smoke on your throat, top shelf. The unflushed burns dark almost black, is rough on the throat and has undesirable taste. If you don’t flush proper your comparison is void. It’s 100% neacessary for quality product

          • Big bullocks on July 16, 2020 at 5:04 am

            101% true flush is a must

          • Sean Binns on September 2, 2020 at 3:49 am

            It might depend on the nutes your using high in nitrates will do that try one without or very low nitrates

          • Josh on September 27, 2020 at 9:23 am

          • VetHigher1GrowR on April 18, 2021 at 3:30 pm

            Bro I was confused as hell on flushing in CocoCoir but after reading your comment the light 💡 came on! I no what I need to do now when it comes to flushing in Coco! Thanks.

          • Jaxon Dean Vaughn on August 5, 2021 at 8:00 am

            Flushing is not just taking away nutrition. Flushing should be done two times. Once when switching from grow to flower stages. Also in the last 2 weeks.
            There are flushing products on the market that will flush the nutrients out. You can create a way better expression of the plant in other mediums than dirt. That is why there is a difference of outdoor and indoor. For people that don’t flush…” Science isn’t right and you should rake the forest too. – D. Trump.

          • John E on October 6, 2021 at 4:25 pm

            I grew my first plant after throwing in a pot and see if it will grow . Got really lucky until the end when I burned it baaaad. So had to do an emergency chop. Dried and cured them , Going on a month now, and just smoked some. Very strong sativa, and smooth as can be. Ashes aren’t white or black but a mix. I was unbiased and ignorant going in (still am) but my first experience seems to lean towards the not flushing because it seems unnecessary. I have five plants growing now in DWC So I’m going to try one of each. Both sides have good arguments so I’m just gonna see for myself

          • Bob on December 26, 2021 at 5:14 pm

            I find people who need to flush are overfeeding.

          • B.i.g on March 15, 2022 at 7:10 pm

            Yo trev I flush but down to 200 ppm then let em dry out n eat wats left for 2 week…do u think I should get ppms lower

          • Ooofymcg on August 31, 2022 at 3:56 pm

            Hey if they want to smoke salts, let em have it. Not my cup of tea though. I definitely cheat before harvest and taste test to see what is up, always better after the flush and the terpenes become more prominent. It’s not even 100% about the flush, it’s about staving the plant to move more of it’s energy into to buds. The death roll of the plant. You get more medicinal value in your buds that way.

          • Sam on March 9, 2023 at 12:23 pm

            Good to consider the PPM of your water source. for example if your using tap water with a PPM of 250 then a 500 PPM is really 250 PPM in soil. I think a PPM of 200-300 after last watering and wait about a day a gallon for medium ( 5 days for a 5 gallon medium) to dry out and have dry soil before cutting down. if wet medium during cut will take alot longer for buds to dry out and higher risk of mold. By leaving some buts your not robbing plant of any last min growth or gerth to buds and its not enough to effect flavor or harshness or black smoke

        • Mack on February 14, 2020 at 11:24 pm

          Zero science behind your claim. Zero proof. Just he said she said bro science. It’s people like you that create stupid growers.

          -I flush for 1.5 weeks. I give my plants 48 hours of darkness before chopping.
          -Then I hang my buds for 7 days.
          -Then I cure my buds in Mason jars with a 62% humidty boveda humidity pack and let them sit and cure for 2 months.

          The end result is the smoothest, cleanest high.
          The smoothest smoke with ZERO harshness on your lungs
          And nothing but pure white ash when it burns.

          I’ve had triple A that’s not flushed or cured properly and it tastes like mexican brick weed.

          People smoke my bud and say it’s the cleanest smoke they’ve ever had.

          So your friends are idiots and you just dont know good weed.
          Half fun smoking your fertilizer stud

          • Rob Gee on March 21, 2020 at 9:17 pm

            Sorry, Mack, Flushing doesn’t do anything but let plants finish up most growers truly never complete the entire stage of a plants life. I owned a Hydroponic store and trust me I know I heard every horror how a so-called experienced salt farmer messed up their girls but to tell you the truth most people think growing MJ is easy I sold so ballast, hoods every single nutrient, additives I could 3 months later they would walk back in to sell their equipment back, some just gave them back too. And I could tell a Candy farmer they never asked about anything just walked in grabbed nutrients by the gallon paid and were on their way ( I’m a Candy grower) have grown for 36+ years and hell yeah I would sell the **it out of flushing agents and make every grower believe they had to flush and growing in water culture of any kind I would 100% flush because the use of chemicals nutrients like Advanced Nutrients, the worst of them all, just like G.H I loved G.H until they sold out. Listen NPK you don’t need all those additives, you only need a 2 part or 3 because of your Base, your Grow, and Bloom I do use Blackstrap throughout the grow and 1 tablespoon all the way to my last week, I only water one more time without anything else and always keep a little Epsom salt on hand use it every other week if needed. That’s it. Stop wasting time and money look at the trichomes they will tell you I’m done.

          • Sean Binns on September 2, 2020 at 3:52 am

            Is it the flush or the cure that makes it smoke so well.i have heard its the curing.the slower the better.

          • Losfederales on October 1, 2020 at 4:16 am

            Burping the jars still or is it not required with humidity pack

          • Tony on May 22, 2021 at 5:02 pm

            Hello Mack I am just finishing up on my second auto flower grow. I liked the steps you mentioned on your harvest and want to follow your recommended flushing steps. My first auto flower grow was in soil. It turned out harsh in my lungs and throat almost to the point I could not stop coughing. This new second attempt at an auto flower grow I went with a coco coir with a compost mix worm castings and organic dry nutrients. What’s available to me is the Dr. Earth veg and bloom nutrients. I also live in a high humidity area. Right now I am at the end of week 10 of my auto flower grow and 1 of my plants is showing fall color changes and see buds better than my last grow in size and structure. Some clear but mostly cloudy with very few amber trichomes starting to appear. Should I start my flushing now?

          • Trina Perrault on September 7, 2021 at 11:39 pm

            Love it! Question for you Mack … I grew mine with no chemical outside, I’m just wondering do I still flush if I just grew straight up on just great soil and fertilizer, plus the proper sun for light?
            Lost but trying ✌️
            Thx tpcitygirl.

          • Floweir on November 30, 2021 at 11:23 pm

            Been growing for about a decade and this is my exact process with the exact same results as yours every single time. Clean, pure smoke. No cough. Head hit inside 6 minutes. I stress them HARD the last week. The plants know they are dying and dying plants produce their best fruit.

          • Nic on December 21, 2021 at 4:32 am

            Do you still have to burp with those packs in when curing?

        • Rayne on September 30, 2020 at 12:00 am

          They literally have scientific data out on it now. 48 hours isn’t bullshit.

        • Rayne on October 15, 2020 at 9:21 am

          Actually sorry bud but they’re are studies done on darkness. Also growers are testing they’re own crops showing a 1.5 to 3% increase in THC, and it changes the Terpene profile

        • Bell on January 3, 2021 at 7:49 am

          I have had the red LED from a timer caused my plants to go to seed. so you are wrong when you say the dark is not true although very minimal quick exposures I do not think cause seeding problems long term exposure. causes stress on the plant an causes her to go to seed to protect herself.

        • miguel on February 14, 2021 at 8:46 pm

          I’ve smoked many a fine bud over the years. Having just moved to a legal state I tried my first grow with great success, Blue Dream.. After a three month cure, my buds taste bitter and extremely harsh to smoke with an almost chemical flavor. I thought flushing was nonsense. Not any more.

        • Ben on April 24, 2021 at 5:43 am

          Mate ngl i believe the people who done this is a pro setup with loads more plants then you and your mate.

          • Brian Jones on January 10, 2022 at 12:09 pm

            WOW Mack! Kinda harsh aren’t ya?

        • HemaN298 on August 26, 2021 at 4:57 pm

          Thats true i grow 20 years there is no need for flush it just kill the plant , if the buds smell or tast bd then probably u over fertilezer it ,if the nuts are ok there is no need for flush!

        • Jack on November 23, 2021 at 6:28 am

          Hey bro have you ever heard of a plant with a salt level really high and it actually pushes salt crystals out of the bud ….. I ask my friend had a massive amount of smoke and it literally had salt on it , lol 🤣 , he weighed an ounce and in the bottom of the cup was like two grams of salt bro 😂😂😂😂 I told him someone probably did it to up the weight , or ????

        • J.Peter Marx on December 9, 2021 at 3:45 am

          Some strains will respond to the dark… Hope you enjoy consumption of your nutrients by not flushing… whether it is organic or chemical. I can tell when it’s flushed completely by how the large fan leafs snap off with no resistance. If you give a large fan leaf a tug and it doesn’t snap off like a dead leaf( I tug on a green one not a yellowed one ) it’s not flushed… Flushing breaks the bond from the nutrients and forces out any leftover nutrients to be consumed. Therefore the plant is free of any nutrients. Anyone who disagrees and doesn’t flush is consuming nutrients for sure. Not to mention by flushing (I do hydroponics) you can push plants as far as possible and get a superior product in the end.BEEN GROWING FOR 30 YEARS!! Trust me folks.. disregard Bee Deezles post he’s a moron.

          • BURQUELYON on October 10, 2022 at 12:41 am

            I am on my second year and I wish I’d read all these comments way sooner. So much info and it’s all super useful even the morons add to the ganja soup. Your input cleared up several questions for me. I hope to grow for the rest of my life. Flush you fools it’s a no-brainer.

          • TRAVIS BLOW on November 26, 2022 at 9:45 pm

            So by flushing it makes it way easier to pull the leaves off ??? Like they just flop off like nothing when they’re flushed correctly

        • Jim Christiano on May 3, 2022 at 4:49 pm

          I have noticed more cloudy tri’s early am than I do late afternoon.. so I do harvest around dawn.. never put a lady in the dark for days b4 harvest so can comment.. still a novice grower.. happy buds!

        • Juan Gonzalez on July 27, 2022 at 8:18 am

          You didn’t do your test right. Try again. It’s been proven by people much smarter than you. Sorry your results were off. Research, research, research.

      • Vwolff on April 15, 2020 at 7:14 pm

        So how many days in that week do you flush your plant?

        • Ifono on May 23, 2020 at 10:07 pm

          Love it

      • highplainsgrower on August 23, 2020 at 3:39 pm

        So I have been just running water for last 10 to 14 days and my smoke burns white
        I just bought flawless finish and I am trying it now to day is aug 23 and I will be chopping some time in the next 7 days as it say for hydro only 2 to 4 days depending on tricorme in one month i will get back on here and tell you if there is a difference visuals difference is yea the bud looks more fater and definitely has more tricorme obviously it would with running nutrition for a extra week or so and yes it is the same genetic sweet amnesia

    • Linda Truax on July 13, 2019 at 6:41 am

      I found this information very helpful but could use an update from an experienced grower.

      • Don on June 20, 2020 at 3:42 am

        simple question how do you flush planet earth? my plants are outside in the ground how should i flush them? ding ding ding hope the light goes on. such BS in the name of ripping people off for profit. flushing is a joke.

        • Tadhg on June 22, 2020 at 8:51 am

          Plants grown outside in natural sunlight go trough a process of flushing themselves when they know the time is right #knowitall

          • The truth on October 2, 2021 at 7:52 am

            What a load of crap. Outdoor organic plants don’t flush themselves. Don’t spread bullshit

        • Blaine on July 15, 2020 at 2:29 pm

          Flushing is required in potted plants because excess salts need to be drained from the home the soil, flushing is not required for plants grown in earth, earth is the home the soil it’s vast literally limitless to the plant, therefore minimal use of fertilizer or nutrients toward harvest is all that is needed before harvest. Got it now?

          • Justin Morgan on February 2, 2023 at 6:27 pm

            Hey I’m new to growing. This was my second grow, first indoor grow, I’ve read as much as I can on grow process and tips. Though It caught me suddenly a little late in the grow cycle, Northern lights I noticed lost trichomes, Bruce Banner was cloudy and Carmel, and I forget the 3rdone. anyhow I cut em down. Point is to I did not flush the plants, I think the last dose was a week before, and a dose the same day of cutting. But check it out it’s been 7 days now. Northern lights I was afraid after reading I think would not be potent because it lost the trichomes partly. I hung upside down in grow tent for 3 days, then canned it, burping it twice a day, humidity outside the jar checked maintained 50 to 65% temp 68 to 72.
            I just broke some out today and I can’t tell because I smoked 2 kinds and not sure if Northern lights is going to be any good but Ill say this much about it I was stoned before I new it and I don’t try to get plum stoned I just hit it a few times and carry on.
            Question is about the trichomes falling off before harvest, and also the not flushing.
            I did read the comtridictary side to flushing saying it does no good to flush because deposits from fertilizer are within it whole plant and it makes sense what they say though that it does not effect the quality of bud weather flush or don’t.
            I need to know better about for my next grow starting up.
            Thanks for ant replys

        • CoyoteKen on November 9, 2020 at 11:52 pm

          Thank God it doesn’t rain nutes on Earth….or it might need to be flushed….. Hehehe

          • Nope on December 17, 2020 at 3:02 pm

            I am still trying to figure out how flushing ‘rips people off.’
            Using less nutrients is some how more expensive?

          • Jorge Clay Meister on September 14, 2022 at 1:01 am

            you mean nuts not nutes, nature will always take its course but humans are here to nurture and learn from nature which begets botanists and scientists…humans have to look after nature to produce healthier and stronger plants or everything will go wild and all cannabis heavily seeded…we figured out the flowers are better without seed so our joints don’t pop in your face…just like now we are learning how to get potent pot without harsh and chemical tastes…so it is worth to experiment with flushing and do your own prognosis ….is it natural like sunshine will naturally flush your weed maybe not but pinching plants to grow more shoots or buying that perfectly balanced soil is natural then I’m sorry but flushing sounds like there’s something there…afterall we so naturally give the plants perfect blend of fertilizer that nature doesn’t so why not try to maintain or minimize those fertilizers from entering our bodies… we’re here to learn and create better snd better yields which are smoother but pack a punch rather than plants dripping with fertilizers snd chemicals…so which is better.

          • Deez on October 10, 2022 at 6:06 pm

            thunderstorms produce nitrogen

        • Scotty on December 12, 2020 at 8:59 pm

          No u dont need to flush organic , if in the ground u cant flush and dont need to.

        • Albert on December 18, 2020 at 10:19 am

          When it rains it helps to keep your plant’s flush. Ding ding ding

        • Kathleen williams on December 14, 2021 at 12:33 am

          No B’s fool mother nature gets flushed by God via alot of rain before fall fool

      • Robert107 on May 18, 2021 at 1:44 pm

        Lots and lots of conflicting info & quite funny too.,to head both sides ..I’d love to just know yes or kniw..I have four plants I think I’ll flush 2& leave 2..on the first one I’ve just finished a 2nd week of overdrive,the trichomes are starting to go cloudy on the first one that’s due tharvest ..I’ve been flushing it for 3days now..I was going to start feeding it dialled down nutes ,to an ec 1-1.2 going in and the same ,maybe 2:0 at the most run off ,I don’t know if I’ll need to now..should I just keep checking my trichomes and see if they’ll go cloudier/ milkier while I complete my flush tomorrow morning,or should I start feeding it those dialled right down nutes..I’ll soon find out,last check with the loupe tomorrow morning will decide? If anyone can help ,I’m all ears I. All I kniw just now,if the trichomes haven’t clouded more tomorrow,I’ll probs add them ,but was advices to make sure I keep the ec at 1-1.2 on the front end and similar but no more than 2.0 in the run out..any advice ,I’m all ears???

        • Jorge Clay Meister on September 14, 2022 at 1:04 am

          what the hell is a nute

    • John O on October 23, 2019 at 4:47 pm

      Wait til 20 percent of tricomes are amber and then turn all lights off for 3 days and then chop her down and hang.

      • Doug on November 1, 2020 at 8:34 pm

        Explain the dark period and why.

    • dave on July 21, 2020 at 6:11 am


      This is about flushing, and if you don’t know how to harvest, go find a site that talks about that.

    • Jim gensler on September 5, 2021 at 7:54 am

      Wait till they are all Cloudy, that’s the point of highest level.

    • Bigdave on September 21, 2022 at 8:04 am

      are you sure the new growth isn’t light stress . personally I try to harvest when I have more reddish hairs then milky white but before they turn brown is keyif it’s not stress and your hairs are still white let it grow grow grow

      • Bigdave on September 21, 2022 at 8:10 am

        sorry .flushing I usually flush once the trichome are starting turn mostly milky ,new growth is fine I tend to see a good bit new growth during. but I’ve only been flushing going on my 5th plant now so I’m still learning.

    • Justin Morgan on February 2, 2023 at 6:16 pm

      I also had a northern lights auto flower,. I actually had 3 going for my first indoor, just second grow. I think I done well, on Bruce Banner plant I cut it at the right to time cloudy trichomes along with Carmel.
      In question of the Northern Lights, I overlooked it and let trichomes start falling off. I just harvested 7 days ago, I recently tried the Northern Lights but also tried Bruce Banner and before I new it I was stoned haha.
      I just wander if the bud looses potency after the trichomes come off?

    • Alan Einfeld on March 18, 2023 at 9:23 pm

      Sounds like they are re-vegging. Is there a light source near your grow?

  2. Don on December 23, 2018 at 5:52 am

    Please do tell of any other industries that practice this stoner “Art” of “Flushing”? Don’t get me wrong i am a firm believer in nutrient reduction at the end of the plants life cycle.

    • Mark on January 22, 2020 at 5:42 pm

      Exactly Don. Do you see greenhouses doing this? Nope. Do you see tobacco farmers doing this? Nope. This is purely stoner science.

      • TeK-NiKaL on February 7, 2020 at 5:26 am

        I’m an experienced grower. It’s simple… use the Advanced Nutrients flushing agent as directed and enjoy the white ash and smoothest smoke ever. Im not a schill… just a lover of quality buds. I’m very sensitive to harsh smoke. It’s simple for me. I flush with the AN agent, I don’t get a sore throat. I smoke something that hasn’t been flushed with an agent I get a sore throat every time. I’m sorry folks but that black ash is from nutrients left locked up in the plant. A plain water flush will help, but it doesn’t do the complete job. AN is correct… the nutes chemically bind to the plant at a molecular level. Plain water won’t break those bonds. And the reason you don’t see tobacco farmers doing it is because the cig companies add all sorts of other chemicals to the final product anyway. Why worry about nutes when they’re adding arsenic to the tobacco. Please be smart and don’t be lazy. If you want quality product that stands above the rest… you must use a flushing agent. I don’t flush for weeks. I think that will affect your plant growth. I flush my medium with approx 1 gal. Of water each… then use the flushing agent. I let it sit for no longer than 24 hours… then flush my medium again with another gal. I let them sit for a day or two… until my medium is beginning to get dry… then harvest. Easy… and then you must have a proper dry. Don’t rush it! Keep your temp and humidity constant with a gentle suction of air in your drying area. Your dry should take at least 5 days…7 days is optimal. You must allow time for the proper conversion of thc-a to thc. I know it sucks to wait… but the best growers are patient.

        • C on March 22, 2020 at 2:24 pm

          No agent needed. Just flush, water I mean with warm water the first week then cold the next. Ne sure to ph water around 6.5.

        • Jorge Clay Meister on September 14, 2022 at 1:07 am

          absolutely and well said….we grow it we have to look after it too

      • Bud420 on May 7, 2020 at 1:56 pm

        Farmers do over fertilize with up-to 10 different additives. So NUTE build up in fruits vegetables etc. not the same comparison. Flush. What do you have to lose?

      • Joey Not Mark! on May 20, 2020 at 7:48 am

        Mark, what are you getting in a little tiff for? It’s not like it’s your plant is it!? So what does it matter to you whether people flush their plants or not? are you going to smoke it? People can grow cannabis how ever they want to grow it it’s a bloody plant!, it’s not hard is it! people like you do my head in, with your know it all cannabis science.!! :O

        • Alan Einfeld on January 20, 2021 at 7:35 pm

          Dude, this is a discussion. If you don’t like it, leave. If you disagree, say so, and then tell us why. Don’t take this so personally, no one’s attacking you. Flushing can’t hurt. If your yield isn’t where you want it a couple of days or a week won’t make much of a difference. Most of us experienced growers agree that flushing makes for a smother product, otherwise it wouldn’t have caught on. We aren’t in the habit of shooting ourselves in the foot.

          • Rebecca Wilhite on September 25, 2022 at 12:15 pm


          • Ferries on March 17, 2023 at 3:38 am

            Hi Allen and all the pro’s. I am just a guy that plant seeds in my garden outside and hope that some of them produce some good stuff (don’t even know the type). I would like to know, since I do not use any nutrients, etc and just water the plants – do I still have to flush and how/when? Thanks for interesting tips to all you guys, such as stressing the plant before harvesting. Must say that my harvest is normally harsh on the throat and I would like to improve my harvest which will be done in approx. 3-4 weeks.

        • Brian Jones on January 10, 2022 at 12:15 pm

          👏 👏 👏 👏

    • Sherrin Ungren on October 3, 2020 at 12:30 pm

      This is the most exciting time for outdoor growing and for me a lil stressful getting it right!! Pouring on the bloom finish then flushing a week and watching the color turn:-) I take close up pics of buds at night.. So beautiful!!

    • David on October 25, 2020 at 4:45 am

      Lettuce Abound Farms in Minnesota (A Commercial aeroponic lettuce farm) flushes 12 hours before harvest, and claims it makes the lettuce sweeter.

      Here, is the source I am referencing:

      I don’t know how valid the claim is, but It is an industry outside of the realm of stoner that swears by it.

      • Walter the white on March 1, 2022 at 4:37 pm

        Good work researching!!!

      • "Randy Marsh" aka Alan Einfeld on March 18, 2023 at 9:31 pm

        Those industries don’t care about you, and sadly neither does Big Weed. It’s the family run, boutique growers that will flush the best, because they care. Support your local growers!

    • "Randy Marsh" aka Alan Einfeld on March 18, 2023 at 9:26 pm

      If you don’t want to smoke nutrients, a ling flush is necessary. Big Weed is losing it’s Trgridy on that one. “Flush you say? Never heard of it.”

  3. Lansterdam Josh on January 11, 2019 at 9:28 am

    Flushing ONLY makes sense in soil if you have over fertilized. When you pass zero E.C. water through a nutrient rich medium, it dilutes the nutriments in the medium. Any other flushing is, indeed, pseudoscience. Or, rather, it isn’t science at all. It’s folklore and nonsense passed on by growers who have zero grasp of actual plant processes. When you feed your plant plain water, or water with supposed “flushing agents”, you are causing your plant to search frantically for the level of nutrients they have become accustomed to utilizing. They do this by taking up too much water, causing cell rupture due to the increase in osmotic pressure. That’s is science. And ruptured plant cells aren’t in your best interest. If you want quality product, learn to dry and cure properly. That’s where the white ash comes from, along with the smoothness. Don’t believe the hype.

    • Jack Herer on March 16, 2019 at 1:57 am

      You’re commenting on a Advanced Nutrients ad attempting to sell some special tailored magical flushing agents. Capitalism can be much more dangerous than folklore and nonsense, there are proper motives behind it’s manifestations such as this 😉

      • TeK-NiKaL on February 7, 2020 at 6:08 am

        It may be ad ad… but it doesn’t mean it’s wrong. Are you saying everything you use to grow was never advertised? I suppose you just was born with the knowledge of growing products? Don’t fool yourself…. word of mouth from your trusted buddy is three same exact thing as this ad. The one difference… your buddy likely isn’t a Botanist or Organic Chemist whose job it is to study these things. I swear by AN products. I’ve used many others and there is simply no comparison. I do feel that you don’t need to use all the suggested AN products they say to use throughout a grow. It’s simply overkill, but that doesn’t mean they don’t have knowledge about how our coveted plants grow. They are masters at the science. Don’t follow the words of others. Test it for yourself, be honest with yourself, follow the instructions, don’t cut corners and reap the rewards. Or just go back to smoking that sub-par bud that YOU think is the best.

        • Sean Binns on September 2, 2020 at 4:00 am

          Id rather get my info from places that dont have a something to gain .

    • Waylon on June 5, 2019 at 5:53 am

      It’s the nutrients in the stem and main stalk’ when hung upside down it leaches into the bud. Any grower can easily try a flushed plant vs reduced nutrient waters plant and see for themselves wich is better. Nature doesn’t flush the plant, but nature probably didn’t expect us to smoke it either.

      • growclean on January 30, 2020 at 8:57 am

        Nature also does not add nutrients to each watering.

        • James Felix on September 16, 2022 at 9:46 pm


    • Topsrite on November 22, 2019 at 8:13 am

      I been doing this for a long time, longer than a lot in this forum have been a live. You are 100% correct! I’ve tied flushing with plain water, distilled water, additives designed specifically for flushing and NOTHING has made any difference. Flushing in my opinion is a fallacy. When outdoors do you flush a field? Of course not. Please stop this nonsense. When stuff is grown in dirt, organically it does have the nice taste. When stuff is grown hydroponically you have stuff that kicks your ass! I prefer the latter, but enjoy both.

    • John on December 3, 2019 at 10:13 pm

      Bullsh_t. I’ve grown organic. I’ve grown non organic. flushing and not flushing. Temp/humidity controlled harvest and cure. The ONLY time it tastes like sh_t is when I havent flushed. Metallic, stingy, harsh, nasty bunk is what you’re telling everyone your product tastes like. Thanks, but no thanks.

    • Scott T Santos on April 24, 2021 at 10:52 am

      I’m with you. Have you ever heard of Cryo – trimming? Cures wet or dry and trims the buds in minutes

    • Tijn on January 9, 2022 at 2:38 pm

      Wow, thank you. You wrote down exactly what I thought

    • BURQUELYON on October 10, 2022 at 1:03 am

      I believe that all of these comments have truth in them. it’s all super important flushed bud is only part of beautiful flower with all the things we all love about ganja. cure and dry are equally important. at least that’s what my novice brain has gathered. smoke clean or chemical it a personal preference obviously

    • "Randy Marsh" aka Alan Einfeld on March 18, 2023 at 9:38 pm

      Is your ash gray or black when you tap it out? Then you are over fertalizing. Your ash should be white. Let your plant use up all the unnatural crap you’ve filled it with by feeding only pH’ed water for the last two weeks, minimum.
      I want my plants hlaf dead from deficiencies by the time I harvest. Saves me trimming time. Industries don’t care about you, and sadly neither does Big Weed. They want their weed to grow in volume until the very last minute. And to do that they either don’t flush at all, or justify to themselves a much reduced flush. Whether or not it’s healthy for the smoker, they don’t give two shits. It’s the family run, boutique growers that will flush the best, because they care. Support your local growers!

  4. Art V. on February 1, 2019 at 1:06 pm

    Flushing is a myth.
    Anyone who has a basic understanding of biology and chemistry would know this.
    Plants don’t incorporate salts or extra nutrients within the plant matter.
    The roots will only absorb and transport the nutrients it needs.

    • jay on March 22, 2019 at 5:51 am

      are you a scientist? I think people should listen to the experts. but that’s my op

    • zylam on April 16, 2019 at 12:54 pm

      There are a few incorrect statements made here. As a botanist of 30 years, The cell’s vacuole contains water that stores waste products and nutrients. In our analogy, the vacuole is the equivalent of the warehouse. It increases tension in the cell walls by pressing against them, thus making the plant stiff. If the vacuoles don’t have enough tension, the plant wilts. Since vacuoles need water to create the tension, too little water will make your plant wilt.

      Acting as a repository, the vacuole also plays an important part in the plant’s fast responses to changes in water level. Potassium is moved from the vacuole to cell fluid when the stomata quickly closes as a response to too little water.

      The stomata can also have fast responses to light, temperature, and carbon dioxide levels, which means the plant is able to optimize photosynthesis and have self-defense against outside threats. If you see some of the bottom leaves of your marijuana plant start to turn yellow and die, don’t panic. In reality, this is a sign of an important process taking place. Like a factory, waste is produced in the cell processes. This waste is kept in the vacuole. When large amounts of waste need to be disposed of, it is deposited into the vacuoles of a leaf. This leaf is discarded by falling off the plant.

    • TJ on June 15, 2019 at 2:37 pm

      Hmm… does the human body work the same way?? (I don’t think so… ;))

    • Champs17x on June 29, 2019 at 8:39 pm

      Then why does the plant intake enough nutes two do kill itself?

      Serious question!! I’ve grown outdoors for 25+ years. Ready to harvest my first indoor crop!! Excited, really wanna get it right.

    • Scott T on July 31, 2019 at 4:34 am

      How do you explain nute burn if they only uptake what they need?

    • B woke on October 9, 2019 at 9:48 am

      If a plant only uptook the nutrients it needed, then you wouldn’t have nute burn.

    • growclean on January 30, 2020 at 9:48 am

      here is your scientific proof

      Most fruit- or yield-producing plants have a vascular system. The vascular system of the plant is what takes the nutrients and water around the plants via the roots (considered the start of the vascular system) and feeds the entire plant, including the leaves, to fuel the photosynthesis process. This, in turn, helps the fruits to develop along with the overall growth of the plant. The vascular system also transports starches, sugars, and nutrients absorbed by the plant around the whole structure, including the fruits.

      As the plant’s vascular system transports these vital sugar and nutrients around the plant, helping it to grow strong and healthy, it deposits the reserves it doesn’t need in certain parts of the plant. The main reserves are held within the stem and root ball. In a normal plant under normal conditions, these deposits are made up of natural, low-level chemical elements that are released when the plant needs them over the different stages of its lifecycle. In hydroponics, a controlled environment means there is an abundance of nutrients and chemicals being fed to the plant, so the buildup of these chemicals that are naturally stored in the plants tissues is not needed. It is vital to remove these chemicals before harvest. Not flushing the plants of these chemicals can leave your harvest unfit for human consumption.

      Within a plant’s vascular system are two main paths. The first path is the xylem, which is composed of four different cell structures. It is this path that transports water and dissolved nutrients from the roots throughout the plant and its organs. It also stores substances such as dissolved nutrients and water for later use. An easy way to remember it is to note that the xylem transports liquid for the plant to drink.

      The second path is called the phloem. The phloem is made from four different types of cell structures that transport the sugars made in the leaves throughout the plant and its organs. The plant can turn any of these unused sugars into starch and store them for later use. An easy way to remember this is to note that the phloem transports food for the plant to eat.

      The Flush Factor

      The first part of the flush process is to stop any further intake of nutrient elements via what the plant is drinking, through the xylem, and replace it with plain water. The second part is to flush out as many active chemical elements as possible that are already present in the plant’s vascular system. This is where the term ‘flushing’ comes from. The faster the plant is flushed of all active chemical elements, the faster it can move on to the next stage of the process. This is the key to the process.
      Water performs this process naturally in the wild over a much longer period of time. Hydroponics differs greatly as it uses constructed systems to get the most out of the plant in the shortest amount of time possible and to the best of its potential. So yes, while water works for this part of the process to a certain degree, a flushing agent will work faster. How? Well, it’s designed that way.

      While the whole process is complicated, the principle is simple. Think of water as a shape. For argument’s sake, let’s say water is an L shape. When this shape (the water molecule) is sent around the vascular system, it dilutes the active elements by picking off the chemical molecules. While the shape of the water molecule may seem ideal at first glance, it is not the best or the most effective shape.

      In comparison, let’s say that the flushing agent’s shape is an X. As you can see, this shape will be more effective. It’s basically four Ls back-to-back, so therefore should be four times as effective as the L shape. As this molecule moves around the plant’s vascular system, it will attract more chemical molecules than the L, thus diluting and flushing the active chemical elements out of the plant faster. As soon as the vascular system is not providing the plant with the nutrients it needs, it will start to release and use up the reserves it has stored previously. This is the next stage of the flushing process. Getting the plant to use its reserves faster will not only clean the plant of unwanted chemicals faster, it will also mature the produce faster.

    • Experienced on September 6, 2020 at 4:27 pm

      If plants never take in more than what they need it would be impossible to ever over-feed. How does chemical burning occur then, if not because it took in too many nutes? Have you never seen nutrient lockout? Trust me the plant takes in whatever consentration of nutrients that are present for the roots to absorb. They can’t pick and choose the proper proportions. There is no magic filter built into roots. I’ve seen a plant develope necrotic rust spots and begin curling within 5 hours of feeding in hydro. They sent a picture the second day and 1\3 of the plant had leaves hanging straight down limp almost all had turned orange and had begun to shriveled up. I’ve had a friend reverse a feeding schedule and cause a nitrogen lockout the slowly yellowing the leaves from the bottom up.

      Of course this flushing solution is snake oil. You could easily taper off towards the end of flower. Organics don’t really need to be flushed. As long as you don’t saturate growing mediums with too many nutes, you shouldn’t have a buch of excess nutrients to dilute down.

    • Brutaltruth on March 21, 2021 at 8:12 pm

      Uh, *nutrient burn* or *toxicities* ring a bell

    • SirRoddo on September 17, 2021 at 1:56 pm

      Explain how you get rid of nute burn then?

    • Tinman 15 on February 9, 2022 at 5:16 pm

      I dunno why this is heated.Ive allways grown in dirt pots and flush for 2 weeks.Never cough and its allways been better weed than anybody i know.What im doing seems to be working.I recently agreed to a side by side comparison on this.I will let ya know in 6 months.

    • "Randy Marsh" aka Alan Einfeld on March 18, 2023 at 9:41 pm

      I’m a Marine Biologist and a Fluvial Geomorphologist. Are you really saying this to me? What is your scientific background? Highschool biology? Flushing works. Trust me, I have my own Tissue Lab.

  5. Don Chievesalot on February 1, 2019 at 3:25 pm

    Force feeding is the issue.. Let em take what the want make what they want and stay as long as they please. They will reward u in the end.

  6. Mr g on March 8, 2019 at 7:27 pm

    I’ve been flushing with water fr years and always had the same taste off different stranes! So i know there must b more to flushing, so i read up on its do’s and dnts, it was then i came across the final solution! Now we’re talking!

  7. Scrogzilla on March 14, 2019 at 5:27 pm

    I have smoked both flushed and non flushed product that I have been involved with, several times over the last 15 years,(trying different methods with different strains) and all the bud smoked s that was flushed was a lot more smoother than the buds that had not been flushed..
    Patients even noticed the difference and said that “this batch was smoother” or “this batch was harsher”..
    Im not a botanist but imo.. Flushed tastes better in the long run.. And the more fresh water that goes through the medium the better.. I have yet to find a grower that states that they over water at harvest and some put up to 80 litres through each of the plants over a week/two weeks.. And that includes soil growers.. At thw end of the day you can see the affect flushing has on the plant amd when the plant realised there are no hight levels of nutrient to imbibe we see the dark green leaves start to turn yellow and die off as the plant uses up the nitrogen left in them.. Buds swell.. Trichomes increase.. Buds dense up and start to try to save themselves and try to develop seeds.. As long as you dont let them go to far and chop before the plant has a chance to seed thwn yiu will find that flushing gives a better overall product.. Regardless of curing time..!!.. Whether you are able to cure for six months or only a couple of weeks..!!.. If your turn around is swift then you need to ensure you flush with a high amount of fresh water.. If you have six months to cure then you dont have to flush as hard.. But imo either way the more you flush.. The less chemical shit is left in the buds..
    However.. Organic feed is different..
    Ever had that weed that is dank and has like a slight/strong smell of either duck/chicken poop.. Or has that baby sick smell to it?? Yet it still smokes smooth and is nice.. Well there you have an organic product that may or may not have been flushed long enough coz obvs they are using soil mix mediums and haven’t flushed long enough.. But it still tastes nice.. The shitty chemicals we buy from the grow shops.. NEED TO BE FLUSHED…
    Otherwise it will taste like shit…. Thats my experience anyway.. Blessed are all those who enjoy and are enthusiastic about this plant.. X

    • Brian Jones on January 10, 2022 at 12:37 pm

      Do what you prefer 😉 get a life!!!

  8. bryan occoner on March 16, 2019 at 4:31 pm

    flushing with water for at least 7 days in soil. you will notice a cleaner smoke . no blah ash clogged bong . no popping sounds. clean taste .
    what do you have to lose ? last 7 days there no longer growing there are always extra nutrients stored in the plants to use up.
    if you think flushing is a myth then flush a single plant and not the flush the other label them. and you will know what is what.
    for the flush solution that is another story. will say i wont waste my money and leave it at that. keep it green .

  9. jay on March 22, 2019 at 5:53 am

    can anyone say nutrient lockout, I can and it took a while before I could feed again. just saying

  10. Raymond Charles Buschow on March 22, 2019 at 1:15 pm

    I like Don’s Philosophy. I simply don’t feed them the last week of flower.

  11. Archaic on March 25, 2019 at 2:22 pm

    Explain to me how a plant “uses up” phosphorus and potassium? I’m really curious as to how marijuana growers can violate the law of conservation of mass but tomato and corn growers have never been able to. Please take a damned botany class before you spout out this fiction next time.

    • TeK-NiKaL on February 7, 2020 at 6:23 am

      Please stop comparing marijuana to food we eat. I know they say tomatoes grow like marijuana but there is one major difference. We’re aren’t smoking tomatoes!! The lung tissue is a completely different biological system than our intestines. The lungs can be scarred and burned by smoking harsh chemicals. How do you know what those leftover chemicals in the foods we eat are doing to your insides? On the other hand when you smoke harsh buds you can feel that. The difference in opinion comes from the simple fact that we are all slightly different when it comes to sensitivities in our bodies. Those with young lungs or genetics may not mind or notice a harsh smoke. The next guy with sensitive lungs or 25 years of smoking under their belt may feel the difference. Flushing with an agent is a proven thing believe it or not . In the end you’ll do what you want… but growers who will settle for nothing but the best know the truth.

  12. Kevin on April 7, 2019 at 10:37 am

    I can’t help feeling skeptical about this article, as it sort of claims to know the science behind what they’re claiming yet doesn’t even provide any proof that it works besides the “fact” that “most experienced cultivators” use this technique. Careful of this website as much of the information is correct but there are some “facts” interspersed throughout that have little science if at all backing it up, and if there is the science out there they don’t provide it. Flushing may very well be valid but we don’t really know for sure, and there are plenty of people out there claiming it is not necessary. The truth is usually more complicated than that unfortunately.

  13. Vincent on April 9, 2019 at 5:34 pm

    The vast majority of “scientists” once thought the earth was the center of the universe, that arsenic was good medicine, and that disease was caused by an imbalance of humors.
    Show me an actual controlled experiment. Someone.

  14. Huff on May 27, 2019 at 11:36 am

    If you only wayer when the soil is dry you wont need to flush period. Do I believe you should stops nutes around 2 weeks before harvest? Yes. I dont allow my soil or plants to build up extra nutes. Ive done both ways and I like only watering when soil is dry. Before I water each time and dig down about 3 inches into the soil. If its damp I leave it alone

    • Ben on September 28, 2019 at 9:11 am

      Exactly, IDK where these people get off calling flushing pseudoscience..there is proven science & many proven studies about flushing & letting the plant use up what nutrients are stored in it. You can taste the chemicals in a plant that was fed bottle nutes & never flushed, not to mention the harsh taste in your throat that makes you cough & the black ash that doesn’t burn smooth at all. Drying & curing can help fix it but it is still very noticeable to someone like me who is a weed snob lol

  15. Curt Richardson on June 2, 2019 at 11:16 am

    The flat Earth and anti-vaccine people are the ones who don’t rinse the medium. People will always reject good advice. Nothing will change their minds.

    • Tbone on June 24, 2019 at 7:00 am


    • Big Al Stockton CA Delta on October 1, 2019 at 2:05 am

      One word organic. If you are not than you are a dumbass you’re poisoning the entire world. Same as if you eat meat or dairy you destroy the environment and the air we breath. ORGANIC NON GMO PLANT POWER is the only way. No flush pure and natural the way it is supposed to be

      • John W on September 22, 2020 at 8:40 pm

        I have to disagree with ya on the food comment lol. Love a good steak. Cow farts are the problem haha.

    • Vlad100W on July 11, 2022 at 1:00 am

      Nonsense. I am all pro flat earth and anti injector genetic modification. …. And I flush. Both canna and the toilet.

  16. Prometheus on June 12, 2019 at 1:21 pm

    Educate yourself on plant biology. The idea of flushing only came about because of closet weed growers who think they have a grasp on anything that grows without any actual knowledge. Until you can properly explain what nutrients the plants takes up, how they do it, why they do it and when (without googling it) then you have no idea what’s going on. Farmers don’t flush their corn crops, strawberries etc the last few weeks. There to this day is still absolutely zero proof flushing the plant helps with harvest, taste, yields whatsoever. Unless you have scientific reports to supply, like the rest of the know it all potheads, sit down and listen to experts. You are a follower not a leader

    • B Woke on October 9, 2019 at 9:58 am

      You say this when I, as well as countless other growers, professional and personal have actually taken the time and done a side-by-side study.

      This is what I did. Same mother plant with 6 clones in outdoor soil. Indica dominate hybrid. 3 flushed 2 weeks prior to harvest, 3 given nutes until 3 days prior to harvest.

      After harvest, dried 7 days, cured 6 weeks. Flushed plants slightly denser, smoother taste, better smell….just all around better product.

      No myth, hype or bull.

    • John on December 3, 2019 at 10:24 pm

      We don’t smoke corn or strawberries, we eat them. Different topic altogether.
      “There to this day is still absolutely zero proof flushing the plant helps with harvest, taste, yields whatsoever.” Hahahaha….. Zero proof….. that’s really kinda like saying there’s zero proof vitamin C does anything good for our bodies. I really feel sorry for the people who take grow or harvest advice from you.

    • Canuckgrowz on December 27, 2019 at 2:59 pm

      @Prometheus. They sure do The seasonal grow cycle of corn is dependent on rain to grow and to be flushed in the early fall.

    • TeK-NiKaL on February 7, 2020 at 6:41 am

      And you are simply wrong bro. All this hating on flushing has wrecked the industry. There are so many poor quality buds on the market now because people are lazy and don’t flush and believe the naysayers. And make sure you’re using RO water. So called purified water isn’t that pure. If you want the best use the best.

      • C on March 22, 2020 at 2:51 pm

        Flushing yes purified water no. Straight tap left out 24 hours then ph to 6.5-7. You just had to take it a little too far with the purified. Ever drink rain water? There is nothing pure about it.

    • Allan on September 22, 2020 at 11:15 am

      The thing is this. Farmers use additives to maximize yield and size and DO NOT care what ,if any, effects there are on humans. Being doing it for decades. They do not flush in practice because of time and money. It takes time to flush and money to buy the agent. There is NO benefit to ensuring taste is a priority. They want the product on the shelf and sold. Try strawberries from California. They look good but taste nothing like strawberries and are really a mass produced glob of organic material they can call strawberries.

      So for argument sake, suppose flushing makes no sense. The result is the harvest occurs at about the same time, so flushing does not cost time. It will cost some money which will be lost. How much are we talking about, a few bucks?

      Suppose flushing does help the quality of the product. It will not cost time to flush, you need to be cognizant of when to flush. You will invest a few bucks BUT you have already bought good seeds, growing medium, various additives AND 4 to 6 months of time tending and nurturing your plants so is buying a flushing agent a game breaker? Not from where I sit.

      So is there an argument for adding more nutrients vs. a flushing agent. Not really. We are only talking about a few days up to maybe 14 to flush which are the same few days or up to 14 which the plant would have access to nutrients. Does the plant use those nutrients or is it using stored nutrients and the additional nutrients being wasted?

      In the end, it probably makes sense to flush. It seems reasonable that a flushing agent binds to things that the plant does not need and eliminates them. It seems reasonable that the stored nutrients are used if no more are added the final days. It seems reasonable to say if the nutrients are flushed or used, the final product will not have the same level of nutrients if the plant had been fed till its last day. It seems reasonable to say a lower level on nutrients present in the plant would result in a smoother product.

      So if it looks like a duck, quacks like a duck then perhaps it is a duck.

      Use a flushing agent, there is nothing to lose and possibly a better smoke on the upside. Enough of all the yes and no bullshit, I cant believe people wast so much time and energy debating a mute point.

      • Richie on August 3, 2021 at 11:40 pm

        Best comment so far for me. 😊

      • Vlad100W on July 11, 2022 at 1:06 am

        Totally agree.
        You just can’t compare supermarket strawberry to the homegrown…. It’s like inflatable Barbie vs Love of your life 😍

  17. Linda Truax on July 13, 2019 at 6:49 am

    Loop Would like to know as much as possible about flushing vs non-flushing. And when you should begin …..and does hanging them upside down really help….and what about growing inside vs outside in northern state during the warmer weather.

    • C on March 22, 2020 at 2:57 pm

      No need to hang upside down, makes better sense to cut each branch at main stem and just hang them, or like me I have dry racks and I just throw branch with buds in those and get to full manicure asap before it dries too much, then just let clean buds dry on racks proper length 7-14 days, at proper temp and humidity 65-75 degrees 30-50%. Cure as long as possible but that’s rarely a option.

  18. Matt Hutchins on July 17, 2019 at 11:37 am

    More perpetuation of unscientific myths and outright lies. You should be ashamed. Vitriole like this is why cannabis growers are mocked in the horticulture world. NO serious grower flushes for 2 weeks. Only those who still believe in old wives tales like hanging your plants allows the resin to run down to the buds, and splitting stems increases potency.

    The ONLY thing you can “flush” out of your plant is the old, nasty tasting water which can be replaced with fresh clean water. THAT’S ALL. This can be accomplished in just a few days AFTER plants are already ready to be harvested.

    The most important factor influencing taste and burn quality(aside from a proper cure) are RESIDUAL SUGARS. Sugars burn harsh, black, and taste terrible like a burnt marshmallow. Again a few days without food is enough to allow the plant to burn it’s sugar reserves. You really want to ruin you crop? Bombard it with bloom boosters, carboloaders, and commercial flushing agents full of sugar.

    If your plants arent green and healthy when you harvest, then YOU’RE DOING IT WRONG. PERIOD. I’ve judged multiple Cannabis Cups over the last 30 years and the best tasting cannabis I’ve ever had was grown by BushyOlderGrower. His plants are dark green and 100% healthy at harvest. His flower disappears into white ash when burned.

    ” ‘Nuff said.”

  19. Jim on August 6, 2019 at 5:51 am

    I just want some hard scientific facts. You know evidence. The human mind can tell itself anything and believe it. Anecdotal is not the kind of eveidence science relies on. Why dont you get your team of science minors to do a study and prove it? You could test everything and stop the actual debate.

  20. Big Buds on September 7, 2019 at 7:36 pm

    Sorry I have the best plants and I grow outside and only use water no chemicals. I don’t care who or what said it. Once you use chemicals on your plants. It is absorbed into the entire plant. It is now in that plant. You can’t flush it out. The chemical are in there till harvest. Then people smoke the chemical. It truly can’t be good for you. So my point being is for a healthy smoke and safe smoke. Don’t use chemical. They will grow wonderful with just water. I am proof of that. People mass produce weed and go for quantity not quality and healthy weed.

    • Tim on June 21, 2020 at 7:26 pm

      What would happen if you clipped a mature limb from your plant and put it into something like a vase with plain water for a week ?

    • GuyAboveMeSucks on September 29, 2021 at 8:37 pm

      Have you done any soil tests to determine what is already in your soil? Perhaps there are enough nutrients in the native soil to feed the plant without having to add anything. Will this last forever? Probably not, because the plant is accumulating them.

  21. afdas on September 9, 2019 at 10:55 am

    and not one person has done a side by side or offered any evidence other than a bunch of stoner talk

  22. Archaic on September 15, 2019 at 10:56 am

    This is one of the most misleading pile of poo articles I’ve ever read. Flushing is a myth that is unsupported by any modern horticultural science. Here, have some real science:


    • Zen on May 4, 2020 at 10:35 pm

      @Archaic. Finally someone provided some real evidence. Flushing is just a bs waste of time and some people who did try to see the difference themselves were just more lenient with the fact that they thought just because they “flushed” it actually did something. Flushing is bs don’t waste your time

      • Milo on September 16, 2020 at 10:09 pm

        If you read the conclusion of that study, or even the Abstract for that matter….it clearly states that they didn’t flush to save on irrigation costs, which conversely is what the whole study focused on: Minimizing water and soil use to maximize profit while maintaining the same yield. The study didn’t focus on quality or taste, just max yield with minimal soil and irrigation frequency.

    • novawolf034 on August 7, 2020 at 8:06 pm

      I liked the thesis. End result, no difference in flushing, but it was noted that there was no significant difference in final yield from using non fertilized water in the final week or 2. So flush or don’t flush, it’s the same result. The flusher will save money in fertilizer.

  23. Ryan on September 23, 2019 at 1:09 pm

    What if your using fox farm potting soil not coco? How long should i flush for?

    • TRIX on January 25, 2021 at 6:45 pm

      I use solely water for one week And I use Foxfarm soil and nutrients

  24. Cookiecat on September 30, 2019 at 7:51 am

    Flush to remove nitrogen – with- pk boost… then dry and cure to oxidise remaining potassium and phosphorus…. just my 2p…

  25. Jsmoke on October 2, 2019 at 4:20 am

    Farmers don’t fertilize up till harvest.

    • C on March 22, 2020 at 3:06 pm

      Thats because farmers use time release fertilizers and manure.

  26. Jim on October 2, 2019 at 2:04 pm

    So a little truth and a whole lot of crap and speculation. The harsh taste and black ash is almost always a nitrogen issue. Nitrogen is water soluble and will leech out of mediums like soil with plain water where elements like phosphorus do not, but this is a huge topic in itself. Too much bad info on this, people grow a certain way and notice what produces a better product under specific circumstances then come up with an unscientific reason for why this occurs then another tries the same practice under a different set of circumstances and has a negative effect. N is an element that can translocate within the plant and pot normally goes N deficient towards the end of its life cycle hence the yellowing leaves starting from the bottom. To make this short most soil growers would probably benefit from flushing to allow the denitrification process while hydro clay ball growers can just reduce N towards the end and end up just fine. Ill also mention that because plants don’t suck in nutrients its pushed in via osmosis they certainly don’t just take in what they need but again that’s another huge topic.

    • C on March 22, 2020 at 3:11 pm

      Fox farm recommends stopping N at week 6 on a 8-9 week strain so less or no watering only near end is needed. One doesn’t need to flush P or K out because that naturally processes itself during dry. I still water only last week so maybe two or three water only feeds at end.

    • Jurgen on November 28, 2021 at 6:44 am

      It is a bit concerning that an article written by a nutrient company does not even understand basic plant processes. For example the article states: “Any grower who has experienced nutrient burn knows the argument that plants cannot expel excess nutrients holds no weight” This is absolute rubbish!
      “Nutrient” burn is caused by the fact that the fertilizer in the water around the roots is of a higher concentration (electro conductivity) than that inside the roots and therefore the process of osmosis cannot take place properly since osmosis by definition is the movement of molecules, in this case: water with dissolved minerals from a low concentration to a higher concentration. Since the nutrients are too concentrated outside the roots osmosis slows down and even stops leading to the plant having to move water from other parts in order to dilute the concentration inside the plant in order for normal metabolic processes and transpiration to take place. This water is fristly taken from the leaf tips leading do them dying off. Nutrient burn is infact a form of dehydration.
      Once you flush you are diluting the concentration outside of the plant roots allowing normal osmosis to take place again.
      THE PLANT DID NOT EXPEL any nutrients!

      Flushing makes zero sense from every possible angle. But if any legitimate peer reviewed study can prove me wrong I’d be more than happy to change my views on it. Anecdotally I have given buds from the same unflushed plant to a bunch of friends and told them one bag was flushed and the other one not. Everyone agreed that the flushed is better tasting and smoother. They were shocked when I told them it was the same unflushed plants.

      What does make major economic sense though is to taper off the strength of nutrients during the final weeks, simply because the plant does not require large amount of nutrients to ripen.

  27. warren on October 24, 2019 at 10:54 am

    after 2 weeks of flushing can plants be harvbested while soil is still wet or damp

    • C on March 22, 2020 at 3:13 pm

      Not bone dry not wet, somewhere in between.

  28. Shortbritches on October 25, 2019 at 10:36 am

    I agree with me Prometheus ,I have grown for 52 years almost 95% of the time organically in soil ,I have tried flushing on numerous occasions and I can not tell the difference .maybe if you grow using chemical fertilizers??? But if grown really organically in dirt I do not see a reason to flush it is just a waste of time and $$ if using a flushing agent.,

    • C on March 22, 2020 at 3:16 pm

      Look at supersoils. They feed til end, no flushing, mostly or all organic. So I agree with you. Only use of full or hybrid synthetic nutes should require any flushing.

  29. Farrah Kellington on November 30, 2019 at 8:37 am

    Ever tried smoking an I flush plant… smoulders and doesn’t burn!! That’s all the proof you need!

  30. Keith on December 5, 2019 at 5:49 am

    Flushing is a hoax. No commercial grower of foods does this.
    Also, the removal of toxins and nutrients idea is bogus. If there is a build up of potassium in your plant, somehow, how does flushing remove this? Potassium is a solid. Where does it go? Does it jump off the leaves? Trav back down the root system, into the soil? Evaporate? No. No. No. No.
    Flushing is a myth. Don’t waste your time.

    • C on March 22, 2020 at 3:19 pm

      Nitrogen is really the only one that should be flushed out, but that can be obtained by not feeding heavy N few weeks before cut. Maybe a water only feed or two. P and K are naturally released and transformed when drying.

  31. Bill on February 19, 2020 at 7:56 pm

    I don’t flush, did a test with some of snobby friends. Told them they were getting 2 different plants, one flushed, one not. It was the same bud from a non flushed plant. They said the “flushed” plant was smoother than the non flushed :).

    The plant will do whatever it can to keep the nutrients in the bud. Unless you let the flower wilt, it will have the same amounts of nutrients feed or not.

    Be honest, do this experiment yourself, you won’t be disappointed.

  32. Kingkong4293 on April 4, 2020 at 9:04 am

    I’m a new grower and I started my plants off on the 12 12 cycle right off the back is that ok or am I robbing them of nutrients? I have 4 plants 3 are about 11 weeks old and one is about 8 they are all flowering good but the seeds I have I’ve collected over the years so there are both regular and hydro seeds I have but cant tell the difference in them so I’m kinda winging it which is bad but im using mushroom dirt with full spectrum lights and I’m trying to find out when is the best time to harvest because I dont have any tools to look at the tricone color I can only really see the pistils some are white and reddish orange any advice?

  33. Ant on June 21, 2020 at 1:56 am

    You only need to flush if you have a salt build up.

    For example in coco as long as you have not used too many nutes during the grow And every time you water you make sure you get a good run off say 20% Then generally speaking the salts should not build up much.

    Personally I flush anyway even though after 9 weeks of feeding at EC 1.0 to EC 1.4 my run off is only 0.7 or 300ppm.

    My mate that does not bother with run off and used EC 1.4-1.8 his EC run off was 5.0 or 2500ppm!!! No wonder his plants looks dark green and toxic looking with all sorts of Root mass PH issues. Remember less nute is more! Especially in coco.. let the plants take what it needs dont over feed them. The manufacturers say to use 2-5ml per Ltr that’s crazy stuff never use more than 1ml per Ltr of anything apart from root stims.

    I flushed ujng Luke warm water! Important do not poor load of cold water over your girls. Warm the water up over 24hours before. Not too hot either just luke warm.

    Use flawless finish in the first 20ltrs and then another 50ltr of just PH Plain water PH 6.2 in coco give or take. (Based on a 15ltr pot)

    my initial run off was ec 0.7 (low already cuz I don’t over feed and my run of each time I water so salts don’t Really build up)

    As for the flush or not flush debate it’s obvious it does work I’ve been a toker for decades. But if advice would be learn from those that actually do it and have results not the people that have been to university for 4 years and think they know everything…. experience is key to everything in life especially growing! It took my 3 grows over 4 years to finally nail it don’t give up.

    And definitely flush!

    • jesse henson on May 19, 2022 at 10:06 am

      proven bro science just like the 2 day dark period stop spreading bro science

  34. Glen on July 3, 2020 at 10:43 pm

    Flushing has been 100000% debunked.

    Don’t believe people who tell you something is a fact when that fact just happens to sell their product.

    Read this…


  35. jonathan steve Llanos on July 18, 2020 at 10:46 am

    If you dont have a magnifying glass try telling by ur pistols they should be 90-100 orange meaning ready to harvest

  36. Benjamin on August 12, 2020 at 2:21 pm

    How might you be able to implement flushing for an outdoor grow using Top-bud harvest method (instead of whole plant) ? I notice I have one plant where the main cola is ready for harvest, but side branches are still maturing.

  37. Sean Binns on September 2, 2020 at 4:02 am

    Whats in this flushing agent?and how much of its in the plant when i harvest? Id rather just cut my nutes back,more so closer u get to harvest.use nutes that do not have nitrites in them towards end of flower and slowly dry and cure the buds.low and slow is best

  38. URL on November 28, 2020 at 12:12 am

    … [Trackback]

    […] Read More Infos here: cannacon.org/dispelling-the-myths-the-importance-of-flushing-your-plants-before-harvest/ […]

  39. Jay on December 1, 2020 at 1:00 am

    First off want to thank those as Trev Matt Allan Jim (Bills honesty 💚) and everybody else that KNOWS about smoking, not eating. Ugh.. All of yous experienced in the field and know what they’re talking about.. Amen! I’m a new grower. First grow, using DWC and AN. Can’t stand reading these commercial food facilities “evidence”… So any advice would be awesome guys. I’m at week 2 of flowering and have been using AN. Does anybody have any recommendations on what flushing agent to use? Been using only the 3 part AN. Am going to, only a matter of what product to use and length of time. (Understand only maybe a day or 2 for DWC?) So don’t try to convince me otherwise please. Should I use AN agent or nitro mag myself? Thanks so much guys. Really learned a ton from both who are correct and wrong. Flushing should be done. Theres TONS of evidence and real knowledge in a firld where it only became legal to grow 10 years ago and barely anybody was. Again, so enough with the commercial companies talk. As somebody stated, even with lettuce it was better overall. Information to not flush is nil and should be ashamed if you believe you’re helping people. When in reality youre hurting their product. So what agent or mix should I use for my DWC 7 liter 3 plant AN 3 part only used throughout? While at it. Any tips on things as Big bud and those to help with yields, would be much appreciated. Currently only been using strictly the 3 part. Thanks for all your guys’ help, honestly. Learning through the process, a lot more to it than i thought. Yet, I love it✌🙏. Any advice at all besides which flushing agent i should use, would be thankful. Again it’s at week 2, 3 plants, 7 liter, full change weekly. Top off daily with correct ppm and ph levels. Seems to be going great. Seeing for the next grow or possibly use in flowering now. Ps. Kept micro 4ml/l grow 3.5ml and bloow 7ml. Gives perfect ppm. An issue is my ph is 6.5 and as yous know AN does it itself. Any solutipn to get it down closer to 5.5. Now i know I need to and will flush 🤝. Now what agent do I use?

  40. How to Grow Cannabis – 1 Hit Wonder on December 3, 2020 at 10:47 pm

    […] This involves running water (with a neutral ph, between 5.5-6.8) through the soil until saturated. Flushing generally improves the potency and flavor of your […]

  41. […] any excess nutrients in the soil. The watering period can be anywhere between a week or more, depending on the medium. The rationale behind this is to allow the plant time to use built-up nutrients and consequently […]

  42. Fk the gov. on September 2, 2021 at 12:12 pm

    Blah Blah Blah,,we all love the feeling of growing your own stone. You visit these blogs to try and further our understanding and obtain the best results for the time invested. I’m a outdoor grower and have been since the late 70s , you will have good years,great years and not so good years,(good weather and bad seasons, The strains you grow and how you grow them) to flush or not to flush that is the question “”” The ONLY way to know what works for YOU is to get a half dozen plants of the same strain and do some science. Flush three,and let the others be.. From grow mediums to nutrients there’s a shit load of “Experts “ out there , From YouTube to blog after blog , Take from it what makes Good sense to you and apply it . And you to will be an EXPERT one day. LOL. It all turns out good, From a 1lb plant to a 10lb plant, To flush or Not,, It’s all good and it’s Yours …The sun is shining, a good smoke in one hand and a beer in the other,LIFE “IS” GOOD..Embrace the ups and downs

  43. […] If you're growing in soil, begin flushing between one and two weeks before harvest. If you're growing in coco, flush your plants for up to one week prior to harvest. If you're growing in hydro, your plants only need to be flushed for one to two days. via […]

  44. CDOG on December 22, 2021 at 10:17 am

    I would like to see charts with data. A good experiment that AN can do and share the results are to grow three of the same plants. All fed the same start to finish in the same environment etc. during the last weeks I’d like to see a flush with fresh water, a flush with their flushing agent and one without flushing. While those are happening, I’d like to see the EC/ PPM of each of the substrates to see what a difference the flushing agent makes versus the fresh flush. When the plants are cut down, I’d like to see the test results for how clean each product is, how potent they are and what the terpenes. Last I’d like to see a smoking experiment where 50 people try the three different outcomes and announce which they think is better without them knowing which buds went through during the flush weeks. If you can do all of this, and the flushed plants with your flushing agent comes out the best than I will buy the flushing agent. Otherwise I cannot go purely based off of your word nor anyone else. I would truly like to know that if and when flushing is done right it produces better flavor. I already know it improves color but I personally have noticed a loss of terps.

  45. Kyuss on January 31, 2022 at 4:05 am

    all scientific evidence says “flushing” is bullshit.

  46. […] and believe your plants are suffering from Cannabis Manganese Deficiency, you should immediately flush your grow medium with fresh, clean pH’d water containing cannabis-friendly nutrients. The dose should be regular […]

  47. How to Flush Weed Plants | Premium Cultivars on April 26, 2022 at 8:23 am

    […] some in the sector argue otherwise, the vast majority of substantial gardeners agree on the relevance of flushing plants. Most seasoned cultivators have tried not flushing before harvest and have seen the glaring […]

  48. […] the plants with water: Flushing your weed plants is the best solution to adjust the pH levels of the soil or growing medium. Moreover, flushing the […]

  49. How To Preserve The Aroma of Your Cannabis? on November 15, 2022 at 1:35 pm

    […] this step properly may cause the excessive nutrients to overshadow the pure aroma of cannabis. Flushing well requires a good amount of knowledge […]

  50. How To Harvest Cannabis Plants - Stoned Masons on December 27, 2022 at 4:16 pm

    […] Flushing is an essential step in preparation for harvesting.  […]

  51. Pete on January 12, 2023 at 4:47 pm

    I’m new to this, and could use some advice. I’m ready to harvest, we’ll pretty sure based on the trichomes. I’ve been sing the GH Flora Grow Three Part Series. I’m their site they say to cut each nute down 10 ml for three days. Then use purified water with molasses for a day to flush. I’m going the flushing route. I’ve been scouring the internet on the proper way to flush and everyone talks about agents. Can I get away with what the recommended?

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