I’m not too much into heavy defoliation, but I see people achieve great results, I see in pics or videos, I don’t smoke it or touch it, so I don’t know. I get great results with very little defoliation, I mean I never bought weed better than mine, not trying to brag. I feel like if you heavy defoliate, the plant is going to try to put out more leaves and not focus so much in resin production. What’s your thoughts?
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It’s just one of many training methods. It’s useful to increase air-flow and light penetration.
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The leaves on my last run were stacked too thick, not to. I think the need comes down to the strain/pheno, training used, and veg length
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When you have a few plants, it’s great, but only until week 2-3 of flower. Any pruning past that point will promote vegetative growth, and we don’t like leafly buds-
When you have a lot of plants, or have really big plants, your priorities will shift away…
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I agree with this. I dont even prune “dead” leaves myself, just let the plant do its thing. Once you pull one leaf more start dropping…more leaves = more photosynthesis = more energy for the plant for flowering.
I think this is an “immune” response in the plants. It sequesters harmful shit in the “dead” leaves…like a kidney.
Plus when you defoliate it stresses the plant stunting its growth…
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I do it for air flow. I veg for a longer time.
I defoilate a few times during the grow
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I like to clean up lower stuff that wont get enough light anyway. I don’t like larf.
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I take anything blocking a bud site, or atleast do my best to remove it. My last round was my first aggressive attempt at this, seemed to help alot.
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If it’s dry, you have a lot of airflow, and you keep plants further apart, you can get away with not doing it.
If its humid and you like to keep plants closer together for more light and better yields of higher quality bud, you almost have to defoliate. Large branching bushes will need it more than single cola small flowered clones.
A bud that doesn’t get light will never be as dense as one that does.
If you have a thick impenetrable interior canopy with lots of leaves touching you will eventually get powdery mildew and/or bud rot. Ask me how I know.
You don’t need to absolutely strip plants bare, but removal of top fan leaves will let much more light and air in the canopy. Lanky plants without much leaf (OG kush for example) will need it less than say, a squat leafy Afghani. Somewhere between no defoliation and bare-stripping is probably best. Good time to remove the larfy lowers as well. I don’t like to defoliate all at once, just a bit here and there as needed. Defoliating all at once and on specific branches can dramatically slow down stretch, which may or may not be optimal for what you’re growing.
TL/DR: Defoliation useful
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I’m going RDWC and if I DON’T defoliate on my bush-babies then I risk PM. This round has been 1 defoliation every week for 3 weeks with my UK Cheese and Pink Cookies and didn’t at all with both my Gelato and Kosher Kush. The current ones (UK/PCookies) are in stretch now and will do 1 more at end of week 2 flower.
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Added to the other reasons people have listed; There’s a point at which a fully grown leaf will draw more nutrients from the plant than it contributes, if it’s not receiving direct light. The threshold iirc is 250uMols.
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This is from a cat that went by the handle nmeeks. Thought he did a really good job at explaining this.
Sources vs. Sinks
First of all, you will need to understand the concept of Source vs. Sink within a plant. Pretty self explanatory, a source is any part of the plant that generates more photosynthate (sugar) than it requires for growth, and a sink is any part of the plant that requires more photosynthate than it can produce (or is producing). What is key to understand with this is that a plant tissue can change from sink, to source, and back to sink all as part of the plants natural process. For example, a newly forming leaf (fan leaf or bud leaf) is always going to be a sink, requiring more sugar to grow than it is currently producing from photosynthesis. . . but once that leaf has reached close to its mature size, it is producing much more sugar than it requires because it is hardly growing at that point. . . .and then again as that leaf becomes older and cells start to get older, the chlorophyll will actually lose effeciency and although the leaf may still look green and healthy, it is no longer generating more photosynthate than it requires to stay alive, and therefore older leaves become sinks again!
There are also parts of the plant which will almost always be sinks. Those are things like the roots (obviously no way of producing photosynthate, but still require it), the flowers on most plants because most flowers contain very little to no chlorophyll compared to a leaf, and seeds are always going to be sinks (the strongest sink).
The important reason I am explaining the Source vs. Sink relationship is because when you have too many sinks and not enough sources, your yield goes down and the overall vigor of your plant is reduced. So to maximize yield and sugar content in the final product (the buds), growers should try to eliminate other sinks as much as possible, while maintaining as many strong sources as they can without risking poor airflow or reduced efficiency with too much shading.
Keeping all this in mind, you can guess that a leaf which is receiving less light (heavily shaded) is most likely going to be functioning as a sink in the plant, drawing sugar away from other sinks that you may be more concerned about such as the buds. Removing leaves above the shaded leaf may give it more light, and maybe enough to start generating more sugar than it needs, but the lower down the leaf, the sooner it will be past its highest efficiency and the closer it is to becoming a sink permanently because of photosynthetic efficiency loss. Therefore, I tend to remove older fan leaves (less efficient) first before I go removing mature newer leaves higher up on the stems because they are more efficient.
Now, once you have removed any leaves that are past their prime, you may still have some fan leaves shading other bud sites, which in cannabis do produce their own smaller bud leaves. The larger fan leaves are MUCH more efficient at producing photosynthate than the smaller bud leaves, and because they tend to be more exposed to air flow they will also transpire more, meaning they help more water and nutrients move through the plant compared to bud leaves which have much less surface area and transpire/photosynthesize much less. So, that means it is better to keep large fan leaves, even if they are shading a bud site or two, because they will function as a source for the bud site (sink) and send its excess sugar to the bud. If you remove the fan leaf, the bud is already functioning as a sink, and so will have to get the rest of the sugar it needs from a different fan leaf on the plant (different source required), meaning a different sink is now getting less than it was because it is sharing its sugar supply from its own fan leaf. . . . this kind of sharing and relocating of sugar pathways takes extra energy in itself, and is not beneficial even if the bud site is no longer being shaded and can produce slightly more sugar on its own from the small bud leaves.
In conclusion, remove old fan leaves especially if they are no longer receiving any direct light. Try to maintain as many sources on the plant as possible by getting as much light and air flow to the newer mature fan leaves as possible. Remove any very low sinks that are far away from any strong sources because they will generate almost no photosynthate on their own, along with drawing photosynthate away from other sinks that are more local to the source leaves higher on the plant. And don’t worry if your bud leaves are shaded, because they are sinks anyways, so the plant is pumping all the excess sugar from local fan leaves to the nearest/strongest sinks it can find (your buds)!!
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Very good info, thanks.
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Bookmarking this post
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I am as well.in my cab I’ve been cleaning up here and there to keep everything open. Ready to get new ten up and see how it goes once have more space!
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When I run mine, I never really defoliate. I like to tuck more than yank. Tuck leaves to expose budsites. I only remove dead leaves and anything that is hiding a budsite that can’t be tucked. I feel like leaves are where excess nutes and energy is stored. Just my opinion. I could be wrong.
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Interesting point of view, but since someone said something like unhealthy and bad looking leaves are a Hotel for pests and diseases I always trim them.
Thanks for sharing, @PlantShepherd, never saw it that way, will keep in mind from now on … 
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You are most welcome sir! I like to think of the production of this plant more as an art form. Everyone gets to paint their own masterpiece, but lets share colors. 
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Do you notice that when you pull one, more pop up but if you dont they remain the few “dead, yelow” ones?
When ever i pulled the leaves on a plant they got replaced by at least 3 more. Kinda like those multiplying balls…
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