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A critical look at preharvest flushing

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
The way I see it, a plant (any plant) needs food and energy right up until it dies. Some food will be stored within that plant, of course - but not all of it. To me, withholding food before harvest day is like turning the lights off for a few days before the chop - you've just wasted the day(s).

Only difficult part is figuring out what food and how much of same they actually need at that point.
 

CareStaker

Nug of the Year: 2014, 2015 - Nug of the Month: May 2014, May 2015 - Creme de la Creme Photos: Jan 2017
Great post...very informative and valuable information. On my previous grow, I did an experiment with my Blue Dream plants. I flushed 3 plants after week 6 of flower. I did not flush the other 3 plants but only fed them ph'd water. There was no noticeable difference in quality or taste. The flushed plants finished 3 days earlier and had slightly smaller buds. My plants were in soil in 7 gallon smart pots. I flushed with 30 gallons for each plant. That's 90 gallons of water used to flush 3 plants. The other issue I dont like is that flushing saturates the medium with so much water that it can take 7-8 days for the plant to dry out...the overwatering condition definitely does not help with final bud size and quality.
This matches my experience, all of it. Flushing with lots of water can release stored nutes into the medium, spiking levels including N levels...and at week six, yeah, small and poorer tasting buds.
 

Doo

Well-Known Member
Is there anything I can do if my buds were dried to quickly? Had some hanging for 5 days and when I checked on them they were crispy as crackers. Went right to a jar when I saw it. I know about adding the stems and will do so immediately. Did I screw this bunch up? The high is still good but the dry/cure process still needs a lot more time.
Bovida Humidpak 62% might help.
 

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
A growing expert, lol? My neighbor is growing fat - which means he's going to be, one day... but he has not actually attained that state yet.
 

Doo

Well-Known Member
A growing expert, lol? My neighbor is growing fat - which means he's going to be, one day... but he has not actually attained that state yet.
Member of the Month...Cool!
My "expert" earns his living that way in a shop. I use his expertise and it has worked out well. I have watched him deal with others at the counter, he is smart. I am smart enough to know when to ask. I am a senior growing my own meds now. I appreciate all the input here. Still learning but really happy so far.
 

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
Yeah, I wouldn't read anything into that user title other than some people were kind enough to vote for me a time or two. Which is nice and all - but it doesn't come with any kind of genius level talent as a prize.

And I apologise for the lame joke; if I don't post one occasionally, they'll throw me out of the Steven Wright fan club.

I prefer not to "flush." I figure it's better to give the plant what it needs - allowing for the fact that it's needs will, of course, change over time - instead of trying to magically rinse a buildup/overabundance of nutrients out of the plant at the last minute (so to speak) as if that plant was an old sock or something.

I've had some pretty good bud that was harvested from cannabis plants that were planted directly into the ground, and it tasted/smoked pretty good. Those plants were not "flushed." Although occasional pre-harvest Autumnal rain events might have made it seem that way... the amount of water that fell upon the bit of earth that made up the root zone area would have been nowhere near the amount that people consider to be a proper "flush."

But that's just my opinion. As in all things in life, YMMV applies. Lots of people don't, lots of people do. It's one of those questions that are great for stating arguments :rolleyes: - like brunettes or blondes, whose God can smite the best, or what brand of oil should you run in your vehicle.
 

Dusted

Well-Known Member
I grow using recirculating hydroponics. I have been internally debating flushing for years. I have tried it in the past and didn’t notice much difference except the sugar leaves were a bit lighter in colour at harvest. No real way to tell if THC levels were effected unless you do a side by side comparison. I’m at that point again in my grow. I have restricted N for the last few weeks, with high K/P levels, and am seeing deficiencies on the fan leaves as expected.

I checked out the feed schedules listed on General Hyroponics website to see what they said. I have had an issue with nutrient suppliers for years, since they recommend way too much of their product, in order to sell more. To my surprise even they recommend a reduced N regime toward the end and a week or two flush. They do want you to use their K/P add-on and flush additive, but the that is just fluff.

I guess I will go with pH 5.5-6.0 water for the next week to ten days. My plants are about a meter high and haven’t been majorly defoliated so they do have a good reservoir of leaves to cannibalize for some nutrients.

This necro thread won’t go away
 

moderngroroom

Well-Known Member
Gonna call bs on that. No one want to smoke the chemicals. We know from experience flushing makes better tasting weed. No diff in yield either.
Ok well call all bs if thats you want to do.. bc science doesnt lie and you need to understand how a plant takes in nutrients idk why such a harsh reply but ok....

Buds do not take up nutrients. The plant uses the nutrients you give it to create the SUGARS that the buds use to bulk up and create the weight that you want at harvest. There is no logical reason to starve your plant just when it should be producing the biggest buds. It's the dry and the cure that create the smoothness and the taste that people think is created by flushing.
 

The Germinator

Well-Known Member
Ok well call all bs if thats you want to do.. bc science doesnt lie and you need to understand how a plant takes in nutrients idk why such a harsh reply but ok....

Buds do not take up nutrients. The plant uses the nutrients you give it to create the SUGARS that the buds use to bulk up and create the weight that you want at harvest. There is no logical reason to starve your plant just when it should be producing the biggest buds. It's the dry and the cure that create the smoothness and the taste that people think is created by flushing.
Keep reading. You'll grow up grasshopper. Much to learn.
 

Dusted

Well-Known Member
If you have grown your plants to maturity there is very little bud growth the final week to ten days. The only thing still going on is resin production in the trichomes (going cloudy then starting to amber), which can be done with existing resources present in the plant. I admit to using a very dilute K/P (contains micronutrients) solution for flush.

Plants growing in the wild will scavenge their fan leaves to support flower production late in the fall, since the nutrient requirement is so high for flower/seed production.
 
Gonna call bs on that. No one want to smoke the chemicals. We know from experience flushing makes better tasting weed. No diff in yield either.
Keep reading. You'll grow up grasshopper. Much to learn.
Wow, I've been on this site for only a few days, and this is the reason I was skeptical of coming on this type of site... "misinformation"... A plants roots are it's filtration system...it will only use what it needs...I use "Organic living soil" so, my plants are constantly getting nutrients, and I never flush...flushing "DOES NOT" make your weed taste better than if you don't flush...It's a myth...Some of the best smoke I've had was grown outdoors, (North Cali) how you gona flush that?....All I have to say is read up on how scientists are using root matter and bark, and in some cases the branches itself to filter out bacteria and other harmful matter in contaminated water supplies, don't rely on everything you read here!!!...Peace and grow green things :peace:
 
If you have grown your plants to maturity there is very little bud growth the final week to ten days. The only thing still going on is resin production in the trichomes (going cloudy then starting to amber), which can be done with existing resources present in the plant. I admit to using a very dilute K/P (contains
Wow, I've been on this site for only a few days, and this is the reason I was skeptical of coming on this type of site... "misinformation"... A plants roots are it's filtration system...it will only use what it needs...I use "Organic living soil" so, my plants are constantly getting nutrients, and I never flush...flushing "DOES NOT" make your weed taste better than if you don't flush...It's a myth...Some of the best smoke I've had was grown outdoors, (North Cali) how you gona flush that?....All I have to say is read up on how scientists are using root matter and bark, and in some cases the branches itself to filter out bacteria and other harmful matter in contaminated water supplies, don't rely on everything you read here!!!...Peace and grow green things :peace:
Thank you so much buddy, finally sumbody with some sense and somebody who believes in science ..don't let the site discourage you buddy there a bunch of great people here and some awesome growers from everywhere.. pictures to melt in for a yr
 

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
I'm more a fan of giving the plants what they actually seem to need (and being conscious of the fact that this need changes over time), so please don't take this as an argument for "flushing," lol - but:

A plants roots are it's filtration system...it will only use what it needs.
How, then, do you explain things like nutrient toxicities and nutrient-burnt tips?

I have also had the misfortune of once buying bud that almost seemed fireproof, lol. Aside from the whole "nasty taste" issue, it was like trying to keep a rock burning (and I think I saw sparkling a time or two). It wasn't because it was wet, either; this stuff was dry.
 
Dang i brought this thread back to life:high-five:, this is a very informative thread that everybody should know instead of wasting time and starving plants on flushing ...science does not lie...........:48: