Is Pre-harvest Flushing A Myth?

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Glow

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Like most myths mate your hypothesis which leads to conclusion is flawed. Thus (hypothesis = flawed leads to conclusion = flawed) What is happening is that if you fail to provide N at a time when the plant requires N it will yellow or as you call it fade. If you perhaps read some books you'd come to learn how nutrients are transported and used in photosynthesis and carbon petitioning. N particularly is very important in canopy photosynthesis. I.e. Since about half of leaf nitrogen is invested in photosynthetic proteins, there is a strong correlation between the photosynthetic capacity (the light-saturated rate of photosynthesis at an ambient condition) and leaf nitrogen content per unit area (Field and Mooney, 1986; Evans, 1989a). Thus, to have high rates of photosynthesis, canopies should accumulate a large amount of nitrogen in their leaves (Hirose and Werger, 1987b

Basically N is incredibly important in chlorophyll production. Chlorophyll is what gives the plant the green colour. By starving the plant of N it cannot produce chlorophyll = yellowing of the leaves.

N though and indeed chlorophyll are of interest during the flush which I have made pretty clear. Does this mean the plant eats up reserves of nutrient ions... No it doesn't... Not even close.
 
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I would offer that during flowering time the plant has less daylight thus having less stored nutrients for the night cycle...esp during the time the plant is producing at night resin production

so I would say yes plants do store and use nutrients
 
MIMedGrower

MIMedGrower

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What myth? In about 1989 i met large indoor growers in new jersey and philadelphia. They “flushed” their soil and switched to water only about 3 weeks before harvest.

They explained to me they could “pump” the plants aggresively with nutrients then basically wash out the excess from the soil before the buds ripened and fade the leaves to yellow some.

They said this allowed them to get very high yield but could cure the flowers to taste smoother sooner for faster sale.

This is the original grow book method and the dutch method.


No “myth” about it until the forums I guess.


I have found through my own testing that when fed minimally to the plants actual needs pretty much to the end the results are better.

I dont think those old growers would argue. They were cash cropping for huge money back then.
 
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I dont think those old growers would argue. They were cash cropping for huge money back then

yea but that is not a scientific response just cuz they were doing it does not mean it is best or even right

old timers have also done lots of dumb stuff also

I am mid aged so I can pick on young and old and you can pick on my dad bod


edit
from above link
Essentially all plants manufacture and store starch during daylight hours, breaking it down during the night, irrespective of the type of photosynthesis used

so regardless of photosynthesis as that does not matter that is the process of creating the "starch" during the night when it is used no light is present so that would prove yes plants to use nutrients stored for later times

meaning flushing available nutrients from soil forcing plant to use its own stored reserves I would think does have validity
 
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G

Glow

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During the night cycle (the Calvin cycle) plants don't photosynthesise (t
What myth? In about 1989 i met large indoor growers in new jersey and philadelphia. They “flushed” their soil and switched to water only about 3 weeks before harvest.

They explained to me they could “pump” the plants aggresively with nutrients then basically wash out the excess from the soil before the buds ripened and fade the leaves to yellow some.

They said this allowed them to get very high yield but could cure the flowers to taste smoother sooner for faster sale.

This is the original grow book method and the dutch method.


No “myth” about it until the forums I guess.


I have found through my own testing that when fed minimally to the plants actual needs pretty much to the end the results are better.

I dont think those old growers would argue. They were cash cropping for huge money back then.

I think the original myth may stem from the likes of the old school authors like Rosenthal actually. BTW I am one of those old school growers - I was out in the bush probably before you were born. I too was told the myth and I too believed it and I too once circulated it (which is quite bizarre really because I should have known better). That is the wonderful thing about myths mate. They spread like wild fire because they are taken on as fact and passed on as such and so on. So for example here you are promulgating a myth that flies in the face of all known science. While I don't for a minute believe this myth others who read your info may/will. Then they run off and tell two friends and so on. And yeah the internet has become a place where fake news and myths are amplified rapidly.
 
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During the night cycle (the Calvin cycle) plants don't photosynthesise (t

lol yes i know,but they still use nutrients during the night..edit that were "stored" from the day

the question IMO is not about flushing

it is about why do we flush or why did people say to flush

the reason OP stated not to was because plants simply to not move nutrients the way humans do and water can not possibly transport these nutrients out

the soil was then presented as the source for nutrients

the soil is flushed forcing the plant to use stored nutrients w/i the plant as the medium no longer has them available through roots system

again it is offered plants don't store nutrients

i don't understand what the discussion is about then

plants store nutrients for future use


edit is the link i posted visible yet?
 
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MIMedGrower

MIMedGrower

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During the night cycle (the Calvin cycle) plants don't photosynthesise (t


I think the original myth may stem from the likes of the old school authors like Rosenthal actually. BTW I am one of those old school growers - I was out in the bush probably before you were born. I too was told the myth and I too believed it and I too once circulated it (which is quite bizarre really because I should have known better). That is the wonderful thing about myths mate. They spread like wild fire because they are taken on as fact and passed on as such and so on. So for example here you are promulgating a myth that flies in the face of all known science. While I don't for a minute believe this myth others who read your info may/will. Then they run off and tell two friends and so on. And yeah the internet has become a place where fake news and myths are amplified rapidly.


I say again. What myth? The old growers were simply leaching their pots to remove fertilizer. They just didnt know the term leaching.

And unless you are 60 years old you havent been around longer than me. I didnt grow. I distributed for a large organization as a teenager and young man.

And no where in eds book is any misinformation he did not correct over the years. His book is the textbook at the canna university i understand. Every modern finding like far red and uvb he already determined back in the 80’s. He sure did not promote flushing. That was jorje. And he learned it from the dutch growers way back.


Leaching pots is a valid tool to use when necessary. I dont believe any schedules will fit every grow anyway. There are no clear instructions that work for every situation.

Too many variables.


You got any garden pics to show?
 
G

Glow

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lol actually that accidentally posted. I was going to explain the Calvin cycle and why this couldn't result in nutrients being used from where it is stored in the tissue but too hard really. One needs to sometimes have a sense of humour:-)
 
G

Glow

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I say again. What myth? The old growers were simply leaching their pots to remove fertilizer. They just didnt know the term leaching.

And unless you are 60 years old you havent been around longer than me. I didnt grow. I distributed for a large organization as a teenager and young man.

And no where in eds book is any misinformation he did not correct over the years. His book is the textbook at the canna university i understand. Every modern finding like far red and uvb he already determined back in the 80’s. He sure did not promote flushing. That was jorje. And he learned it from the dutch growers way back.


Leaching pots is a valid tool to use when necessary. I dont believe any schedules will fit every grow anyway. There are no clear instructions that work for every situation.

Too many variables.


You got any garden pics to show?

Ah so who then started the myth that plants could "cannibalize" themselves lol
 
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also myths do happen for reasons

its usually because we don't have a scientific explanation yet

and after reading on this subject of how and why plants use stored energy esp in annual plants I dont think one is offered yet...furthermore we are disturbing this process by depriving the plant of reproducing further complicating the subject
 
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who started myth on plants can cannibalize themself

the guy who had his stuff eaten or taken and came to the conclusion they must have eaten themselves
 
MIMedGrower

MIMedGrower

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Ah so who then started the myth that plants could "cannibalize" themselves lol


No idea. I learned everything from books and greenhouse guides and university pages.

I only said my plants fade to quickly if i withhold nutes the last 2 weeks and that i got better yield, quality and flavor/smell feeding less and less to the end.
 
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i think equations for grows will change soon anyways

it used to be short term solutions

I have the same area in my yard for now until I die to grow in, so I don't wanna dump a bunch of crap in that area its awesome to be able to figure this out treating it as an ecosystem rather a spot that nobdoy finds and I can best produce for that season

the solutions to problems can finally be met with some thought not products
 
G

Glow

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No idea. I learned everything from books and greenhouse guides and university pages.

I only said my plants fade to quickly if i withhold nutes the last 2 weeks and that i got better yield, quality and flavor/smell feeding less and less to the end.


Lol so we aren't debating then. Good. Solved:-) And agree
 
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yea funny I think all 3 of us are don't flushers anyways still debating

ha civilized debate just for sake of debate

I do enjoy!

oh darn there is the quote button
 
hyzerflip

hyzerflip

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I 'flush' my coco DTW plants for 2 full weeks before harvest, but not because it makes a smoother smoke (it doesn't). I do it simply because the plants no longer need nutrients at that point and pouring them on would be a waste of money.
 
gwheels

gwheels

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I use autopots. On the last couple of rez top ups before harvest i use pure PH adjusted water to top up.

I think leaching is closer to what people mean. Flushing sounds like pouring water on them until you can fix them (like a PH problem you have to adjust).

I do find the taste is better if i really lighten up on nutes in the last 3 weeks or so. Sometimes though i dont time it right so i have had it without a 3 week reduction and that tasted ok too.

I do it out of habit and will probably always do it.
 
hyzerflip

hyzerflip

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I do find the taste is better if i really lighten up on nutes in the last 3 weeks or so. Sometimes though i dont time it right so i have had it without a 3 week reduction and that tasted ok too.

$100 says you've never compared the difference side by side. Try it! 'Flush' one plant and don't flush the other.

Plants eat what they want, when they want. Soil in nature is never 'flushed', it always has nutrients in it.
 
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