Defoliation time or nah

I’ve been picking off dead/dying leaves as they grow
I’m about 3 and a half weeks into flower
When is a good time to start defoliating

@21 days seems to be a popular time frame with a lot of growers . I’d say go for it now

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What do you hope to accomplish through defoliation?

@KeystoneCops well this is my first grow so I’m just going with the flow. I’ve just read alot of comments on removing leaves that cover bud sites and I have alot. But on the other hand if those leaves provide nutrients why would i remove.thats why I ask


You can have my opinion on why most defoliation practices are misguided, if you want. You’re correct that some people will heavily defoliate and still manage successful harvests, so I don’t judge people who do defoliate.


I’d start defoliation now pal. Get some more light through your canopy to lower bud sites. Those fan leaves are to get you through veg. Now your in flower you can get rid. Obvs it’s a personal choice. A side view is always handy. Spot any dark shades areas and trim up to allow light through. Plants look really happy and healthy though. Great work. Keep it green brother


Why is it important to get light onto the cannabis flowers?

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Isn’t getting light on the flowers what triggers the flower to protect itself by extruding extra thc (though it might only do that with UV light)

If that was the case, wouldn’t outdoor plants consistently test higher than indoor? The sun’s intensity and UV levels are unparalleled by our indoor lights.


Getting light onto the actual flowers/bud sights will fatten them up. Otherwise you can have lots of bud sites below the canopy, but there be Larfy and crap. You want dense bud, not airy bud. Hope that helps

Why would it lead to any growth, other than the growth of leaves interspersed among the calyxes?

Note: this is my theory on why defoliation appears to work, but in fact does not make calyxes more abundant or potent.

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Well you could cover all your bud sites and examine the final results of your grow. And compare the results. I haven’t so cant argue why, only that my buds are fat and I allow light onto all of them.

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Let me ask it in another way: why is it more important [IYO] to have light hit flowers than to hit leaves?

If the defoliation plan is to remove all leaves except the ones in between calyxes, then my inference is that the plan values light hitting flowers more than light hitting leaves.

Isn’t photosynthesis the foundation of all plant processes? And if that’s the case, wouldn’t we want to maximize photosynthesis? Where does photosynthesis occur in the cannabis plant?

Note: @HanJolo I mean no offense, and I merely hope to help you and others come to sound conclusions about defoliation. I appreciate that you’re sharing info that was shared with you.


No offence taken my friend. Knowledge is power and everyone here is sharing that knowledge.

I wouldn’t say defoliating is to remove all the leaves apart from the ones carrying the calyxes. Only that removing the large ones covering bud sites is necessary. Theres also alot of discussion that the fan leaves are primarily designed to get you through veg and once in flower, Less important. I cant argue the facts of that. Only that it makes sense to me.

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Sometimes common sense out weighs the hive mind. I will tag covertgrower about his opinion. I think this is how you get his attention.


My personal opinion is that the lower 1/3 of the canopy should be defoliated. Growth can focus better on top.

I’m on the fence of complete defoliation, but some people do it, and they’re successful. Personally I keep any leaf that is not a older fan leaf.
The fan leaves during transition, and into flower really are the first leaves to show any deficiencies because anything that’s needed is sucked from them. At that point in time, if they’re yellow, I pull them. This is what I do.
Your grow may vary.


I think a lot of these ideas start with sound science or at least 1st hand empirical data. But like so many things the signal is corrupted with each new transmission. So the ideas around defoliation sound like they’ve passed through a game of telephone (hopefully that’s not anachronistic).

In my experience a shallow, level canopy of fan leaves is optimal in flowering cannabis indoors. The fan leaves are the only part of the cannabis plant where we find meaningful amounts of chloroplasts. Without them, photosynthesis is reduced. Training and pruning during the vegetative growth towards a level canopy is how I approach seed-flower plants; I find clones in a Sea Of Green more preferable overall though. In both cases, I would defoliate the lowest portion of the plant to create a 1’ space between the soil/medium and the underside of the canopy. That’s about airflow in the interest of pest management. If bud sites form there, I leave them alone usually.

The other reason I defoliate is to regulate humidity. Taking a few leaves off can decrease the humidity a bit; conversely leaving more leaves on can raise humidity. That’s a natural way to help regulate the environment.

I’ve seen proponents of aggressive defoliation taking everything off the plants 2-4 weeks into flower, and boasting about how the plant responds by adding more flowers. There’s no evidence that the plants wouldn’t do better if left alone, since they never seem to show high-population side-by-side studies from clone. And again, I postulate that the plant responds by producing more leaves at the flowering sites, not calyxes. Whether that’s actually better, or just aesthetically more pleasing is open to debate.


I would like to add one comment about the hive mind. According to popular belief my plants should never have survived. I grew from bag seeds, grew in used drywall buckets, used miracle grow potting soil, fed with chemical fertilizer very high concentration nitrogen, fed at bloom very high concentration 12-55-6 bloom fertilizer. They not only survived they thrived. Plants are well over 6’ tall as thick as a bush. I can’t even describe how big the colas are or how many nice big dense buds there are. I have about 100.00 bucks invested in this.

It pains me to see how many people have spent many hundreds of dollars and thousands on this to grow a stick. It comes down to diminishing returns. It seems to me at least if someone can not grow a potted plant what makes them think they are going to grow like a commercial grower.
It is cheaper just to go buy some.


I’m with @Covertgrower I use scrog nets so I clean them up down under and at day 21 I thin them out but not a complete strip enough to let air through the canopy


Depends on the area. $600 an ounce, you’ll make the investment. Alaskan weed ain’t cheap.