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Flushing & Leaching & Final Bud Swell

ScienceGrow

New Member
The purpose of this post is to open a dialogue on the root cause of the commonly encountered phenomena of final bud swell, often encountered in the last two weeks before harvest.

Many new growers are warned not to harvest early, as the final bud swell, occurring in the final two weeks before harvest, can pack on significant weight, resin, and aroma.

Growers are also often encouraged to flush at about two weeks from harvest, and cease fertilizer treatments. The intended purpose is to make the plant use up as much stored energy as possible before harvest, improving smell, burn, and effect.

After extensive reading into plant physiology, I've developed a hypothesis that may explain the phenomena we often see in the last two weeks.

Plant nutrients, whether synthetic in a bottle, or organic in a bag of worm castings, enter the plants roots and xylem as mineral ions, inorganic matter. Most nutrients gain access to the inner root via active transport; that is, to overcome the concentration gradient, the plant must spend energy on moving the ions manually. So, rather than just getting sucked up with the water, which is passive, nutrient absorbtion is mostly active and requires energy from the plant to occur.

Further, once within the root, the nutirent ions are then converted to other forms(assimilation), which also has an energy impact. Creating amino acids and proteins from ions and photosynthetic products is a lot of work!

So, that being known, one can well assume that making nutrients unavailable to the roots, and subsequently eliminating energy use from assimilation, should decrease or eliminate the energy expense of nutrient uptake and assimilation.

Growing flowers, and production of resin and terpenes are also metabolically taxing activities of the plant.

So, perhaps by dropping all that energy consumption that was being spent on pulling in nutrients, is now made free to produce larger flowers, more resin, and more terpenes, resulting in what we see as a magical bud swell in the weeks before harvest.

This should be an easy enough experiment to conduct, and I'll be doing so with my current multistrain grow. I'll simply keep feeding one until harvest, and stop feeding the other. More samples would be great, why not give it a shot?

Oh, and for those using organic nutrient lines or supersoil. This applies to you just as much as the synthetic fertilizer users. Organic nutrients are identical to synthetic nutirents as far what actually enters the plant. A nitrate ion is a nitrate ion, it doesn't matter where it came from, ans the plant will only let specific ions in. And if my theory is correct, the point is to force the plant to live on reserved energy and put all of its effort into building buds. So you should give it a shot too!

Discuss!
 

KidGrow420

On Vacation
re: Flushing & Leaching & Final Bud Swell

The purpose of this post is to open a dialogue on the root cause of the commonly encountered phenomena of final bud swell, often encountered in the last two weeks before harvest.

Many new growers are warned not to harvest early, as the final bud swell, occurring in the final two weeks before harvest, can pack on significant weight, resin, and aroma.

Growers are also often encouraged to flush at about two weeks from harvest, and cease fertilizer treatments. The intended purpose is to make the plant use up as much stored energy as possible before harvest, improving smell, burn, and effect.

After extensive reading into plant physiology, I've developed a hypothesis that may explain the phenomena we often see in the last two weeks.

Plant nutrients, whether synthetic in a bottle, or organic in a bag of worm castings, enter the plants roots and xylem as mineral ions, inorganic matter. Most nutrients gain access to the inner root via active transport; that is, to overcome the concentration gradient, the plant must spend energy on moving the ions manually. So, rather than just getting sucked up with the water, which is passive, nutrient absorbtion is mostly active and requires energy from the plant.

Further, once within the root, the nutirent ions are then converted to other forms(assimilation), which also has an energy impact. Creating amino acids and proteins from ions and photosynthetic products is a lot of work!

So, that being known, one can well assume that making nutrients unavailable to the roots, and subsequently eliminating energy use from assimilation, should decrease or eliminate the energy expense of nutrient uptake and assimilation.

Growing flowers, and production of resin and terpenes are also metabolically taxing activities of the plant.

So, perhaps by dropping all that energy consumption that was being spent on pulling in nutrients, is now made free to produce larger flowers, more resin, and more terpenes, resulting in what we see as a magical bud swell in the weeks before harvest.

This should be an easy enough experiment to conduct, and I'll be doing so with my current multistrain grow. I'll simply keep feeding one until harvest, and stop feeding the other. More samples would be great, why not give it a shot?

Oh, and for those using organic nutrient lines or supersoil. This applies to you just as much as the synthetic fertilizer users. Organic nutrients are identical to synthetic nutirents as far what actually enters the plant. A nitrate ion is a nitrate ion, it doesn't matter where it came from, ans the plant will only let specific ions in. And if my theory is correct, the point is to force the plant to live on reserved energy and put all of its effort into building buds. So you should give it a shot too!

Discuss!

I have learned and use several techniques towards the end of my grows to help swell the resin glands and almost quadruple trichome production. It's a old techinique I have mentioned on here before (around the formus) in guidling and helping people get the most out of their crop... The last 2 weeks of flush is standard. No matter what you grow with or how you grow it. That simple. BUT, in the last 48-56 hours of the plants life another "technique" I use comes into play. I switch the humidity down to 25-32%, then hit em with a 8/16 light schedule. This 8 hours of light and 16 of dark sends the plant into HEAVY Trichome production and swells the resin sacks to the size of grapes. In most cases (with me) the trichome production AT LEAST triples. I also in the last 48 hours like to make a cut at the base of the plants stock. A simple cut half way through the stock or a little less will send this plant into even heavier trichome and resin production. The plant thinks it's being eaten by a deer or animal and when you hit them with the 8/16 sched... Man o Man. It tricks the plant into thinking it's day is defiantly numbered by insinuating winter is upon her and shes getting eaten... These techniques towards in the last 48-56 hours will not only help you get bigger stickier buds. But it will also give you substantial increase in potency. BUT, do not let it go to long or your plant will nanner. And we obviously do not want this. This is why I say the last 48-56 hours. After many tests I find this is the "sweet spot" and wont deal with any nanners. ;) :Namaste::thumb:


PSS: Since this post was about the ending "techniques" used in harvesting cannabis, I thought I would "expose" a few more secrets used by master and advanced growers world wide. :Namaste:
 

ScienceGrow

New Member
re: Flushing & Leaching & Final Bud Swell

Hi there! Yes, these are also commonly used techniques, and, they may be doing what they do for the same reasons as I explained. By eliminating light, you end photosynthesis, a highly demanding metabolic process. By eliminating another energy sink, perhaps the plant has that much more energy available for bud building.

Humidity wise, may just be a stress reaction.

Still all a hypothesis, but it all seems logically sound.

Thanks!
 

ScienceGrow

New Member
re: Flushing & Leaching & Final Bud Swell

I'm also starting to question the efficacy of flushing. On the surface it seems like it works. It's logical, certainly, but I'm not sure the plant can work the way described. Let me explain.

The point to flushing is to remove excess fertilizer salts from the grow medium, forcing the plant to consume it's own energy stores. I feel like this is maybe 100% functional for most parts of the plants, except the part we care about, which are the flowers.

Flowers are sinks, not sources, meaning flowers don't provide anything to the plant, it only receives. So, while it makes sense that maybe the leaves would benefit from a flush, the buds really have nowhere to offload excess fertilizer, if any even exists in an available form within the plant matter. I was also thinking that, rarely do we burn flowers with nutrients. Nutrient burn is caused by excess salts forcing water out of cells, at least in essence. If there were excess nutrients in the flowers, flowers should nute burn. But rarely do they. It appears that the vast majority of nitrogen and other elements we feed as fertilizer, are incorporated into the plant matter, not stored or just sitting, but being part of the cell, so, not something you remove via translocation.

I also joined a forum for growing tobacco. Funny, they're just as tight knit community as over here, with different strains and breeders. Cool stuff.

But anyway, these guys don't flush, and laughed their asses off when I explained it to them.

They then, after composing themselves, explained that flavor and harshness are controlled with the cure. They then described their cure methods, which jive with Ed Rosenthals latest grow guide.

Basically, we all have it backwards. We dry and cure, while they cure, then dry.

It was explained that a proper cure of any plant matter requires a period of fermentation, which begins imediately after chop. Curing without fermentation is apparently not actual curing. The cure breaks down most of the nasty plant material via fermentation, so, cells are broken down, gasses release, and any of those elements that had previously constituted the matter of the cell are released, which these guys say takes between 4 and 16 weeks in low/no light, medium humidity and temperature, with air circulation.

After the cure, they dry it to the right humidity just like us, and then age it for a few years.

No flush, no flushing agents, just a really long, true, cure.

Most of us let the buds dry in about the same conditions tobacco usually cures, little to no light, medium humidity, moderate temps, some air circulation. So, we probably are benefitting from a fairly short cure during our drying period, and if we are letting jars air out regularly (air in, actually, a true cure requires oxygen.) So, if you slow dry, and are good about airing jars out, and you do this properly for longer and longer periods, as everyone recommends, you getter better flavor, as everyone seems to say. If you're doing this, you're benefitting from a true cure.

I also found that while oxygen can degrade thc, light is a much bigger enemy, and if cured properly even in the presence of oxygen, the bud should lose very little potency.

I'm not about to bet the harvest on this, but I will be setting a few buds aside for a proper long ferment/cure. Ed says it's best. Others say the same. All of them say it's all about the proper cure, and that our traditional methods are just quick and easy. They work, but could be much better.

So, anyway, aside from our apparently not curing properly, it looks likely that flushing does nothing at all for the flowers, maybe something for leaves. It definitely clears out soil though, so at the least, you aren't pulling more nutes in.

Again guys, this is meant to be a discussion on what's actually happening in the plant. While I appreciate other harvest tips, that's not what this thread is about. In fact, it's these types of tips I'm trying to understand. Too many people just do things either because they seem to work, or at least do no harm. I want to know why it works, not just that it does.

That's how things like Miracle Grow become so popular. Anyone using it thinks it's miraculous, because they don't understand anything about plant nutrition.

Their shit plant looks great after use. It's a miracle!

No, it's just NPK.

The bud tastes better after flushing.

No, it's just the cure.

And I'll continue flushing until I am convinced one way or the other. I lean toward it not working, but the marketing guys (and at least half of you guys) have me scared to risk it for now.

Debate!
 

ScienceGrow

New Member
re: Flushing & Leaching & Final Bud Swell

Okay, now I'm convinced. Pre harv3st flushing does nothing as far as improving taste, smell, or smoothness of flowers. There may be some benefit to the leaves.

Overall, a proper dry and cure makes for the smoothest and tastiest buds.

Black ash is incomplete combustion, almost certainly an indication of too much water in the buds. The same thing happens when you burn uncured wood in a firepit. It's hard to light, stay lit, hisses and pops, and burns black, at least to start.

Cigar quality is sometimes judged by ash color, with the same myth, of white being better. Of course the real aficionados seem to know better, Cubans produce dark ash. Apparently, according to the cigar guys, white ash is caused by MORE nutrients in the soil.

So cigar people agree white smoke is better, but they attribute it to increased nutrient levels, not decreased.

But the easiest way to resolve this is, keep smoking the black ash. It should end up white. If so, that's incomplete combustion for you.
 

LEDBud

Well-Known Member
re: Flushing & Leaching & Final Bud Swell

Actually the black ash does indicate a build up of nutrients.
a over fertilized plant will taste like its washed out void of its possible great flavor and often causes one to get a sore throat or cough.

Sounds funny but you can test your plants for a its nutrient level by test smoking some of the bottom bud ... I do it all the time.

Before harvest I test some of the bottom bud for the color of its ash and if it burns readily , if the ash is grey and it wants to burn then its good to go

I am smoking some bottom Bud right now or should I say testing , or more accurately both :Hookah:
 

ScienceGrow

New Member
re: Flushing & Leaching & Final Bud Swell

If you believe the ash story to be true, please submit your theory on what is happening. Which nutrients in concentration make flowers burn black? N? P? K? Or is it the sodium, or calcium? Something else?

I'm looking for the truth. But I need evidence, real evidence, not personal experiences. Those are great, worth a lot, but I still need real evidence.

One thing I have evidence for is water content making flowers harder to light, harder to keep lit, harsher to the throat, a bad taste, and the potential to give headaches.

These are all offered as evidence of too many nutes. But they all also can be explained by moisture content, without raising other questions, like which nutrient is causing the problem.

Anyway, I appreciate people's experience and knowledge, but while I may be new to horticulture, in biology, chemistry, and physics I've got an excellent handle. And the best scientific theory for black ash is high moisture content. If better evidence exists for nutrients being the cause, I am more than happy to take a look. I am swayed by science.

Not sure their theory is correct either, but the cigar guys believe the exact opposite as the cannabis guys. They think white ash is an indicator of poor soil fertility. Well, some of them. Others believe it's high calcium and phsophorous. And black ash is magnesium.

The Ash Knows...

And of course, they have their myth busters too.
Cigar 101: Top three cigar myths - Buy Cigars Online

Issues with cigars not being dried enough are: hard to light, keep lit, harsh smoke, bad or no taste.

Sounds familiar.

And for medical taste, I submit ammonia from a bad dry/cure as the chief culprit.
 

ScienceGrow

New Member
re: Flushing & Leaching & Final Bud Swell

If nitrogen is the culprit, why would you check at the bottom of the plant?

No, that provides no new information. Nitrogen is not it. It's moisture.

A bud pulled directly off a plant will 100% not burn anywhere near as well as a dry bud that was fed any amount of fertilizer. If you burn a bud right off the plant you'll end up with a hard black lump in your bowl. Keep burning it and it will eventually go white. But why would you?

Look, flushing cannot work on flowers. Nothing leaves flowers. It's plant physiology. Flowers are sinks, not sources, they don't store anything. It's biology man.
 

LEDBud

Well-Known Member
re: Flushing & Leaching & Final Bud Swell

Nitrogen being a mobile nutrient travels up the plant from the bottom to the top and if need be back to the bottom.. so test from the bottom if you want a by the minute account of the fertilizer level or more so the nitrogen level.
 

ScienceGrow

New Member
re: Flushing & Leaching & Final Bud Swell

I've read that one several times. It does nothing to explain how nutrients are being leeched from sinks. Especially when N isn't just N but is now part of an Amino acid chain, protein, or sugar.

In plants, there are sources and sinks.

Roots are sources, as they send sugars to other parts of the plant. They're also sinks, as they receive nutrition from the leaves.

Stems are sources as they transport nutrients to other parts of the plant. They can also be sinks, receiving nutrition from the leaves.

Leaves begin as sinks, receiving nutrition from other sources on the plant. At about half grown, they become sources as well as sinks.

Flowers are sinks. Flowers do not provide anything to any other part of the plant. Nutrients enter the flowers as sugars and carbs and become part of the flower material. Nitrogen doesn't leave flowers when it's needed elsewhere, as we see in leaves. It is not mobile in sugar form within the flower.

And the end of that article basically agrees with me, saying most problems attributed to not flushing are likely a result of overfertilizing and a bad dry/cure.

I will agree, over fertilizing is problematic, but flushing doesn't fix your flowers a week or two before harvest.

And I still maintain black ash is a result of moisture.
 

Weaselcracker

Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016
re: Flushing & Leaching & Final Bud Swell

I'm looking for the truth. But I need evidence, real evidence, not personal experiences.
SG, this statement doesn't make sense to me, as personal experience always seems to be far more valuable in real life than what you call 'evidence'. Wouldn't it make the most sense for you to try a couple experiments and just test your flushed buds against unflushed ones, and go from there?
 

ScienceGrow

New Member
re: Flushing & Leaching & Final Bud Swell

I'm sorry but the science is not with you. Flushing cannot remove nutrients from the plant, especially the flowers. It's just plant physiology. You would literally have to change how the plants vascular system works to do what you're saying.

Experience is often priceless, but sometimes, it gets in the way of learning something new.

People do what they do when they see that it works. But sometimes it isnt that particular thing they are doing. Sometimes, it's just associated.

So, say you are a great grower. You do everything by the book. You flush, dry and cure properly. As far as you can tell, it works.

But, maybe it's just that you are a patient and methodical grower. You do everything right, so, even the things that do nothing appear to be helpful.

I fully understand the theory and I was convinced too, until I thought about it more, and then verified it in my plant physiology book. And then verified again with a botanist over at the Mad Scientist website.

There's no science behind the 24 hours darkness thing either.
 

Weaselcracker

Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016
re: Flushing & Leaching & Final Bud Swell

I'm sorry but the science is not with you. Flushing cannot remove nutrients from the plant, especially the flowers. It's just plant physiology. You would literally have to change how the plants vascular system works to do what you're saying.

Experience is often priceless, but sometimes, it gets in the way of learning something new.

People do what they do when they see that it works. But sometimes it isnt that particular thing they are doing. Sometimes, it's just associated.

So, say you are a great grower. You do everything by the book. You flush, dry and cure properly. As far as you can tell, it works.

But, maybe it's just that you are a patient and methodical grower. You do everything right, so, even the things that do nothing appear to be helpful.

I fully understand the theory and I was convinced too, until I thought about it more, and then verified it in my plant physiology book. And then verified again with a botanist over at the Mad Scientist website.

There's no science behind the 24 hours darkness thing either.
Is this addressed to me? If so I'm not sure what you mean by 'the science not being with me' or the mention of 24 hour darkness. I didn't say anything about whether or not I flush or don't.
I'm saying it makes sense to test and observe things in real actual life and work from there.
 

ScienceGrow

New Member
re: Flushing & Leaching & Final Bud Swell

SG, this statement doesn't make sense to me, as personal experience always seems to be far more valuable in real life than what you call 'evidence'. Wouldn't it make the most sense for you to try a couple experiments and just test your flushed buds against unflushed ones, and go from there?
Personal experiences are known as anecdotal evidence, which is not to be trusted in science. Personal experiences are marred by biases of many kinds. Plus, people lie. People exaggerate. People misinterpret, misrepresent, misunderstand.

I've done the taste test, and confirm my own hypothesis. Of course, you could call that a result of bias. And that's the problem. It's also why I researched it. I don't have a problem flushing, it's no hair off my back. It probably isn't deteimental. It's just pointless, so I won't do it anymore.

Personal experience is no replacement for knowledge, if the experiences haven't increased knowledge. I'm worth more money to my company than just a college student because of my experience. But, we've hired others who were supposedly experienced, but were worse than our young guys.

Anyway, the science stands on its own. All I hear is pleading and parroting, no refuting my evidence or offering real evidence. Just personal experiences.

I personally feed my plants Guinness every other week and get great results!
 
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