Defoliating In flower??

Kingrow1 said:

Tomatos do not increase yeilds defoliating bushes only vines, this is merely a training practice that works but yes im sure there will be others

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If you do not selectively remove new sets from forming on tomatoes they will never ripen in time for harvests before weather becomes cold.

So for tomatoes at least you need to remove new growth shoots so that the plant focuses its energy on growing the sets you have left to ripen.

I actually found this out this year from my mother who has grown tomatoes for he past 30 years.

My wife and I were growing tomatoes with our children In the garden and my mother pointed me to the removing new sets to allow others to ripen in time.

IME there is a point of no return with defoliation.

Removing all leaves but the bud leaves is too far.

RIDDLEME if anyone remembers him used to do the stair case effect for leaf pruning.

Taking every other leaf off up the stem.

Personally I think it’s a fine line between useable light penetration versus plant matter and plant height.

As I grow using 400w realistically I don’t want a 4ft tall plant with all its leaves on

At most I want to keep 2ft of plant that has the ability to grow what I need on it.

So with a 4 ft plant I would strip the bottom 2ft off it. If that makes sense.

So that I only had 2ft of the top in my active growing area.

ChiefRunningPhist said:

Sounds reasonable but the data, at least with tomatoes, is that defoliating 3/16 lower leaves actually increases yield. @JSheeze might have gone too far (according to the data) but in terms of documented data, some defoliation is better than none. If you can provide some data,your argument would hold a lot more weight, with me at least.

You mentioned defoliating as a precursor to hermie, but the argument that not defoliating leads to PM could also be made. It seems to me that it's situational to the strain and your environment. Some grows are harder than others to control for RH and light height, so there are definitely people that benefit from such environmentally adaptive cropping. It is a tool to be used when needed as necessary and the data points to increased yield with some defoliation.

I'm not sticking my head in the sand. Provide me some data to help me see what so far the one research paper contradicts.

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Finding actual studies on mj is difficult. However applying tomato studies to mj may have ''some'' credit but it needs to be taken with a grain of salt. The growing styles and conditions are often very different leading to miss application. As king pointed out tomatoes are often grown vertically on a trellis. We can apply that concept but not directly. A lot of people grow horizontal but with a net, for example. This changes the way you optimise the canopy, a greater emphasis on topping that in turn appears to play the role of ''defoliating on tomato plants''. If you were to head over to the vertical section you MIGHT find more correlation between mj defoliation and tomato trellis, as they are then a lot more similar in conditions.

The point is, if you take more care over your initial set-up (typically horizontal) to avoid leaf shading or over lapping, you will not have a need to defoliate. Also that defoliating will not yield more than somebody who has got their shit in line.. because if they've topped the correct amount and not over crowding then the canopy is as optimised as it is going to get, as the leaf and bud sizes are as small as they are going to get (in a good way) as to not block each other, or as much.

Yes I also understand people have difficulties with set-ups. But I would be extremely surprised if I could not walk into such a set-up and suggest changes to get the environment more stable. ''I am limited by my set-up'' can often mean ''I don't know, don't want to spend or can't be bothered to change it''.

Thing is for me, nobody has got definitive proof that defoliating works to increase yield on mj when every thing else is in line. That's an important distinction because 99/100 times when a person posts a pic of a defoliated plant it is worse off for it on top of blatant environment/feeding issues. We do have proof that doing too much of it is most definitely bad, so no proof it works, proof it's bad when you do it wrong?. It isn't for me to PROVE it does not work.. since countless growers have already proven that topping and growing in a decent environment with 0 defoliation yields very well. It is up to defoliators to prove this and obviously, given that this topic of many over many of years.. is still raging, that tells it's own story. If it increased yield like topping does, why are these kind of topics not history? you don't see topics from experienced growers arguing ''does topping increase yield''. I am not saying flat out defoliation can not increase yield in a situation where everything else is in line, however.. it is such a huge grey area with 0 evidence of working while having proven downsides for failure that it is better left alone if your goal is max yield. Or better put, if you have not reached max yield potential, why bother with a technique that isn't proven, when you can chase techniques and changes that are.

Flowki said:

Finding actual studies on mj is difficult. However applying tomato studies to mj may have ''some'' credit but it needs to be taken with a grain of salt. The growing styles and conditions are often very different leading to miss application. As king pointed out tomatoes are often grown vertically on a trellis. We can apply that concept but not directly. A lot of people grow horizontal but with a net, for example. This changes the way you optimise the canopy, a greater emphasis on topping that in turn appears to play the role of ''defoliating on tomato plants''. If you were to head over to the vertical section you MIGHT find more correlation between mj defoliation and tomato trellis, as they are then a lot more similar in conditions.

The point is, if you take more care over your initial set-up (typically horizontal) to avoid leaf shading or over lapping, you will not have a need to defoliate. Also that defoliating will not yield more than somebody who has got their shit in line.. because if they've topped the correct amount and not over crowding then the canopy is as optimised as it is going to get, as the leaf and bud sizes are as small as they are going to get (in a good way) as to not block each other, or as much.

Yes I also understand people have difficulties with set-ups. But I would be extremely surprised if I could not walk into such a set-up and suggest changes to get the environment more stable. ''I am limited by my set-up'' can often mean ''I don't know, don't want to spend or can't be bothered to change it''.

Thing is for me, nobody has got definitive proof that defoliating works to increase yield on mj when every thing else is in line. That's an important distinction because 99/100 times when a person posts a pic of a defoliated plant it is worse off for it on top of blatant environment/feeding issues. We do have proof that doing too much of it is most definitely bad, so no proof it works, proof it's bad when you do it wrong?. It isn't for me to PROVE it does not work.. since countless growers have already proven that topping and growing in a decent environment with 0 defoliation yields very well. It is up to defoliators to prove this and obviously, given that this topic of many over many of years.. is still raging, that tells it's own story. If it increased yield like topping does, why are these kind of topics not history? you don't see topics from experienced growers arguing ''does topping increase yield''.

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Topping is also a tool to use, imo. Topping though, won't negate genetics. If a plant has genetics to produce leaves that cover other leaves, no amount of topping will make it genetically change. I would argue that topping actually leads to more overcrowding and more leaf blockage and leaf touching. ???

The tomatoe study shows increased branch numbers and flower sites with defoliation, as well as increased leaf surface area (which is what you were advocating for, right?, leaf surface area needs to be maximized, right?). Also heavier weight per tomato and bigger yield.

Top all you want, but if any of these tomatoe studies are translational, then additionally picking off 25% of the nuissance leaves beginning of flower will increase your yield that much more.

These tomatoes all had 1 top. I'd imagine the relationship is pretty linear and if they had more tops the results would scale accordingly. That's just my opinion, although the increase in yield of tomatoes based on some defoliation has been demonstrated.

If I grew outdoors again I wouldn't touch it at all, I never did. Maybe not as tall as @doublejj lol but 13ft. Indoors, I think is different, but to each his own. I defo for PM prevention/light penetration, as I try to get as many buds per area as possible and leaves will touch if I don't trim some back.

I agree that propper SCROG spacing and veg planning will help mitigate over crowding and many grows are not perfect. I agree. I agree that people get carried away as well.

Flowki said:

Thing is for me, nobody has got definitive proof that defoliating works to increase yield on mj when every thing else is in line.

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Agreed.

CannaBruh said:

There's theory and then there's practice. I see no new evidence to suggest flowers cannot be grown in cases where leaves have been removed even in edge cases where all leaves have been removed we find flowers still grow.

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Actually this is neither theory nor hypothesis, it's proven fact.
https://sciencing.com/photosynthesis-work-plants-5479729.html

Obviously you can remove a few leaves without major detriment but complete defoliation will hurt your plant's flower production. It's plant biology 101.

Have no wish to fight but cannabis is merely a plant like all the others.

jondamon said:

IME there is a point of no return with defoliation.

Removing all leaves but the bud leaves is too far.

RIDDLEME if anyone remembers him used to do the stair case effect for leaf pruning.

Taking every other leaf off up the stem.

Personally I think it’s a fine line between useable light penetration versus plant matter and plant height.

As I grow using 400w realistically I don’t want a 4ft tall plant with all its leaves on

At most I want to keep 2ft of plant that has the ability to grow what I need on it.

So with a 4 ft plant I would strip the bottom 2ft off it. If that makes sense.

So that I only had 2ft of the top in my active growing area.

Click to expand...

But thats extra veg time over a larger number of shorter plants.

I do agree with you though and i doubt id see loss of yeild from a few leaves.

curious2garden said:

Actually this is neither theory nor hypothesis, it's proven fact.
https://sciencing.com/photosynthesis-work-plants-5479729.html

Obviously you can remove a few leaves without major detriment but complete defoliation will hurt your plant's flower production. It's plant biology 101.

Have no wish to fight but cannabis is merely a plant like all the others.

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I liked my point before that removing a few leaves from an unhealthy plant might make it grow better and reduce water needs etc.

This was also a reason why some might see increase in yeild from defoliation

Red4twenty said:

Lol after all these mixed answers among all the arguing that’s exactly what I decided to do I defoliated a few of them and left the others I’m more towards it yielding less stripping loads of leaves this far into flower hence why I stripped leaves on only a few and just added more fans to stop moisture building on the more bushier compact plants only time will tell I shall let you know lol ...... and no need to argue on the topic I expect everyone has there own way of doing things lol thanks again

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Get a dehumidifier, removing some leaves will reduce harvest but if your other option is mold so you lose your entire harvest, needs must. If your humidity has been that high I would treat for powder mildew now as well. Reducing the number of plants in your grow space to decrease the transpiration humidity is a good idea as well.

Good luck on making it to the finish line.

Kingrow1 said:

But thats extra veg time over a larger number of shorter plants.

I do agree with you though and i doubt id see loss of yeild from a few leaves.

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Fully agree hence why I do 5 weeks of veg and training then flip.


Keeping my plants around 2-2.5ft tall.

Kingrow1 said:

I liked my point before that removing a few leaves from an unhealthy plant might make it grow better and reduce water needs etc.

This was also a reason why some might see increase in yeild from defoliation

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That's nice, I like science, long walks on the beach and white wine

Outdoors the sun arcs through the sky lighting the plants from the sides and top, in this configuration the Fibonacci sequence leaves grow in naturally works best.
Here, most of us have static light sources. I basically look down at the plant from dead centre over the tip, removing large leaves hiding colas from my line of sight.
If you time it right and leave the right leaves unmolested now leaves will fill the spaces behind your cola in 3 to 4 days. Noone suggested removing al leaves... For me, it is deciding which leaves I'm going to allow to grow and getting rid of umbrellas..

ANC said:

Outdoors the sun arcs through the sky lighting the plants from the sides and top, in this configuration the Fibonacci sequence leaves grow in naturally works best.
Here, most of us have static light sources. I basically look down at the plant from dead centre over the tip, removing large leaves hiding colas from my line of sight.
If you time it right and leave the right leaves unmolested now leaves will fill the spaces behind your cola in 3 to 4 days. Noone suggested removing al leaves... For me, it is deciding which leaves I'm going to allow to grow and getting rid of umbrellas..

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Actually someone did

rsvp_gardens said:

No magic just common sense. If theres no leaf then theres no energy going into leaf growth so by removing the leaves youre not allowing the plant to focus on leaf growth it only has to focus on flower growth. And yes please look up photosynthesis because light powers plants not leaves. The point of removing the leaves is so flower sites are exposed to as much light as possible

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rsvp_gardens said:

No magic just common sense. If theres no leaf then theres no energy going into leaf growth so by removing the leaves youre not allowing the plant to focus on leaf growth it only has to focus on flower growth. And yes please look up photosynthesis because light powers plants not leaves. The point of removing the leaves is so flower sites are exposed to as much light as possible

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Photosynthesis occurs in leaves and green stems within specialized cell structures called chloroplasts. One plant leaf is composed of tens of thousands of cells, and each cell contains 40 to 50 chloroplasts.

I may as well start grilling burgers in here, like during trim camp, when all the trimmers show up we break out the big grill and cook in shifts ...

ChiefRunningPhist said:

Topping is also a tool to use, imo. Topping though, won't negate genetics. If a plant has genetics to produce leaves that cover other leaves, no amount of topping will make it genetically change. I would argue that topping actually leads to more overcrowding and more leaf blockage and leaf touching. ???

The tomatoe study shows increased branch numbers and flower sites with defoliation, as well as increased leaf surface area (which is what you were advocating for, right?, leaf surface area needs to be maximized, right?). Also heavier weight per tomato and bigger yield.

Top all you want, but if any of these tomatoe studies are translational, then additionally picking off 25% of the nuissance leaves beginning of flower will increase your yield that much more.

These tomatoes all had 1 top. I'd imagine the relationship is pretty linear and if they had more tops the results would scale accordingly. That's just my opinion, although the increase in yield of tomatoes based on some defoliation has been demonstrated.

If I grew outdoors again I wouldn't touch it at all, I never did. Maybe not as tall as @doublejj lol but 13ft. Indoors, I think is different, but to each his own. I defo for PM prevention/light penetration, as I try to get as many buds per area as possible and leaves will touch if I don't trim some back.

I agree that propper SCROG spacing and veg planning will help mitigate over crowding and many grows are not perfect. I agree. I agree that people get carried away as well.

Click to expand...

I think that a correlation between early topping amount and veg light spectrum/intensity plays a large role in how big or small fan leaves become indoor, although genetics still play into it so I can concede that much. It would be a lengthy post to get into that more so I'll leave it there unless you're interested.

Some leaf lap of upper leaves isn't a problem with good air movement/rh control. I'd personally say about a 5% over lap from one upper leaf to the next is safe, 10% doable but I've never really thought too much about that tbh. What I do feel comfortable saying is that if leaves are overlapping from plant to plant top to bottom then that isn't good. That isn't a genetic issue, it's a spacing/growing technique issue.

I am open minded that some yield benefits found in tomato experiments could show some yield benefits in a dialled in mj grow. However it has been years, nobody has objectively worked it out yet. If growers are happy to run the gauntlet on it then happy hunting. I guess it depends on where you are at as a grower, do you like a bit of mystery or are you happy with tried and tested consistency.

My main gripe with defoliation is that it isn't proven but newbs get the wrong idea and butcher plants expecting crazy yields. Then it's a tail chase of ''did I do it wrong'' rather than chasing proven methods of yield increase. It's just a shame for them to fall into such traps.

I think defoliation is popular with the hobbyist growers but growers that do it for the money need the yield and can't mess around slowing the veg phase with topping or defoliating in flower because they don't have enough room or light. I have been tempted to do it on bushy indicas but I just tuck them out of the way. I haven't had any bushy indicas out yield Sativa trees so they don't stick around very long anyway.