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A critical look at preharvest flushing

bluter

Well-Known Member
If your market wants it flushed and you will realize a higher return selling that product, then do it.
Market capitalism really is not hard.
truthfully the market doesn't care. most purchasing legal product have no clue how it is produced.


edit : they actually consider the plant finished before the final water takes place (flush). it's part of the cure process, not grow process.
 
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Elvin

Well-Known Member
truthfully the market doesn't care. most purchasing legal product have no clue how it is produced.


edit : they actually consider the plant finished before the final water takes place (flush). it's part of the cure process, not grow process.
If the market does not care and if not flushing increases the amount of product you can produce, what exactly is the argument?
 

Remystemple

Well-Known Member
I understand the concept of "flushing" in regards to inert growing mediums but how does one flush the nutrients away from the root zone when using soil that contains nutrients?
agreed. like for an out door grow with a dug in bed, there's no flushing that.
 

Emilya

Member of the Month: Mar 2019 - Grow Journal of the Month: Jan 2020
I think you all are analyzing this under some misconceptions. A whole lot of your commercial grows are done hydroponically, and periodically they are going to flush their reservoirs and start with new mixes as is the nature of hydroponics. Commercial growers do flush. Even if I were to grow commercially in large soil containers, I would find a way to bring in a garden hose or something so I could do a flush if needed, and without hesitation several times during the grow... if of course I was using synthetic nutes in soil, which of course I would try not to ever do again.
 

bluter

Well-Known Member
If the market does not care and if not flushing increases the amount of product you can produce, what exactly is the argument?

they are already past the point they consider the plant yield to be increasing when they do the final water and begin the harvest/cure process.

i found this really curious myself. as in, if the plant takes up water, is it not growing ?

to be certain, it's not like they are watering the plant for all that long. once, maybe twice during the seedling to veg stage, that again at the veg to flower stage, once at harvest. again, they are not pouring buckets through. same amount as a standard feed.

it's not really an argument for or against the practice. it's just the industry approach. at least this particular producer. they grow for a very large multinational, and are just one supplier out of hundreds or even thousands. all of their produce is spoken for, they are 100% contracted to one wholesaler.

the whole conversation frankly left me with more questions after lol.
 

Elvin

Well-Known Member
I think you all are analyzing this under some misconceptions. A whole lot of your commercial grows are done hydroponically, and periodically they are going to flush their reservoirs and start with new mixes as is the nature of hydroponics. Commercial growers do flush. Even if I were to grow commercially in large soil containers, I would find a way to bring in a garden hose or something so I could do a flush if needed, and without hesitation several times during the grow... if of course I was using synthetic nutes in soil, which of course I would try not to ever do again.
I find that just by watering until it comes out the bottom keeps my soil from suffering from nutrient buildup so I don't bother with flushing
 

Elvin

Well-Known Member
they are already past the point they consider the plant yield to be increasing when they do the final water and begin the harvest/cure process.

i found this really curious myself. as in, if the plant takes up water, is it not growing ?

to be certain, it's not like they are watering the plant for all that long. once, maybe twice during the seedling to veg stage, that again at the veg to flower stage, once at harvest. again, they are not pouring buckets through. same amount as a standard feed.

it's not really an argument for or against the practice. it's just the industry approach. at least this particular producer. they grow for a very large multinational, and are just one supplier out of hundreds or even thousands. all of their produce is spoken for, they are 100% contracted to one wholesaler.

the whole conversation frankly left me with more questions after lol.
I look at it stickly as a business. The Market does not care so that removes that from consideration. Fertilizer costs money;

Does continuing with these inputs up until harvest increase weight enough to cover the expense with a greater amount of product that you can sell or not?
That is really the only thing a business is concerned with, is it not?
 

bluter

Well-Known Member
I look at it stickly as a business. The Market does not care so that removes that from consideration. Fertilizer costs money;

Does continuing with these inputs up until harvest increase weight enough to cover the expense with a greater amount of product that you can sell or not?
That is really the only thing a business is concerned with, is it not?
totally.

i'm sure they made all those calculations when they made these decisions.
you probably have it exact.
 

Elvin

Well-Known Member
they are already past the point they consider the plant yield to be increasing when they do the final water and begin the harvest/cure process.
I believe what you are describing, is that the industry is stopping with nutrients at the point where they won't work to increase growth, but the plant is still not mature enough to harvest.
If the industry wants to call not fertilizing anymore because it won't affect growth, as a "flush" (instead of flushing for taste), that's fine but it's kind of marketing "flair" is it not? ;)
 

bluter

Well-Known Member
I believe what you are describing, is that the industry is stopping with nutrients at the point where they won't work to increase growth, but the plant is still not mature enough to harvest.
i pretty much think you nailed it.

If the industry wants to call not fertilizing anymore because it won't affect growth, as a "flush" (instead of flushing for taste), that's fine but it's kind of marketing "flair" is it not? ;)
they didn't call it anything.
how much you wanna bet they are just cleaning out the auto feed systems when they do this ? :p

all the flair is left to the retailer.
 

Remystemple

Well-Known Member
i pretty much think you nailed it.



they didn't call it anything.
how much you wanna bet they are just cleaning out the auto feed systems when they do this ? :p

all the flair is left to the retailer.
i've never actually noticed "flushing" or curing every being used as a selling point of any online stores i've ever bought from, now that i think of it.
 

Nunyabiz

Well-Known Member
every feed costs them a few thousand dollars, at just this one facility. there are several places they grow across the country.


i was more shocked to learn they can not compost left over organic material. stems, leaves, roots, etc all have to be documented and destroyed.


it is important to note they have botanists (horticulturists ?) and mineralogists on staff who advised on the growing methods. there is a well-known agriculture college in the province where they hire most of their growing professionals from.
They have on average a loss of 12% yield by flushing.
That wildly makes up for nutrients.
And if it cost that much for nutrients then they're dumber than hell to not go full Living Organic Soil No-till.
Better product, way less cost for "amendments"
 

bluter

Well-Known Member
They have on average a loss of 12% yield by flushing.
That wildly makes up for nutrients.
they aren't flushing by the common procedure described here.

the plants have stop yielding higher weight by the time they do the final water.
at least by their calculation.

they could chop at last feed with zero difference in weight yield.


And if it cost that much for nutrients then they're dumber than hell to not go full Living Organic Soil No-till.
Better product, way less cost for "amendments"
no idea what the cost analysis would be for the way they do it over other methods and media.

the largest richest private investment group in the province pretty much owns it outright. old oil boom money. they likely made sure everyone did their homework.

some sort of organics is a longer term goal. it definitely has a better cost benefit according to what i was told.
there is a regulatory issue currently in the way.

they are growing 48,000 sq ft and are adding two facilities the same size. each place is kind of a big ass square building with another couple squares attached. tornado bait.

i dunno how much it costs to feed that. "thousands" is just the comment i got given.
 

Elvin

Well-Known Member
Here are the biggest takeaways for me:
"To conduct the trial, growers at the RX Green Technologies research and development facility in Colorado cultivated cannabis plants of the strain Cherry Diesel in a coco-based medium. During growth, the plants were fertilized with the company’s brand of nutrients. Four groups of 12 plants each were subjected to different flush times as harvest approached. Each group of plants was flushed for either zero, seven, 10, or 14 days.

Flower samples taken the day before harvest were analyzed for essential plant nutrients. Overall, there was no significant change in the mineral content of cannabis flower as a result of different flushing treatments.

After harvest, the plants were cured and tested for final trimmed flower weight, terpene, and THC concentrations. Lab analysis found no significant differences between the different flushing treatments for flower yield, THC potency, or terpene content."
and
"when the data from the blind tests were analyzed, the researchers discovered that the participants tended to prefer the taste of the flower that had not been flushed at all, although overall, the duration of the flushing period had no impact on flavor, smoothness of smoke, or color of ash. In the results of the study, RX Green Technologies wrote that the trial indicates that “there is no benefit to flushing Cannabis flower for improved taste or consumer experience.” "
Of course, it needs to be replicated and done in other growing mediums but this does seem to show it is unnecessary to do.
 

Elvin

Well-Known Member
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Emilya

Member of the Month: Mar 2019 - Grow Journal of the Month: Jan 2020
Here are the biggest takeaways for me:
"To conduct the trial, growers at the RX Green Technologies research and development facility in Colorado cultivated cannabis plants of the strain Cherry Diesel in a coco-based medium. During growth, the plants were fertilized with the company’s brand of nutrients. Four groups of 12 plants each were subjected to different flush times as harvest approached. Each group of plants was flushed for either zero, seven, 10, or 14 days.

Flower samples taken the day before harvest were analyzed for essential plant nutrients. Overall, there was no significant change in the mineral content of cannabis flower as a result of different flushing treatments.

After harvest, the plants were cured and tested for final trimmed flower weight, terpene, and THC concentrations. Lab analysis found no significant differences between the different flushing treatments for flower yield, THC potency, or terpene content."
and
"when the data from the blind tests were analyzed, the researchers discovered that the participants tended to prefer the taste of the flower that had not been flushed at all, although overall, the duration of the flushing period had no impact on flavor, smoothness of smoke, or color of ash. In the results of the study, RX Green Technologies wrote that the trial indicates that “there is no benefit to flushing Cannabis flower for improved taste or consumer experience.” "
Of course, it needs to be replicated and done in other growing mediums but this does seem to show it is unnecessary to do.
This is only true if you accept the modern perversion of the term flush to include the act of starving your plants at the end by giving them only water.
If you go by the ancient tried and true real meaning of the word flush, attempting to somehow clean out the plant of all nutrients was never even considered... all that was done is to properly "flush" the salt accumulations out of the soil somewhere near the end of the grow so that the buds could finish up properly, feeding them all the way to the end.
 

Elvin

Well-Known Member
This is only true if you accept the modern perversion of the term flush to include the act of starving your plants at the end by giving them only water.
If you go by the ancient tried and true real meaning of the word flush, attempting to somehow clean out the plant of all nutrients was never even considered... all that was done is to properly "flush" the salt accumulations out of the soil somewhere near the end of the grow so that the buds could finish up properly, feeding them all the way to the end.
I'm pretty sure they were studying what "flushing" is considered to be by the Cannabis industry not what you are referencing.
 
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