Thoughts please on de leafing

Although i can see some defoliating is necessary, i don’t recommend too much of it. Air flow can be critical if mold is eminent. But your plants need leaves to make buds.
A couple of things I think are worth mentioning when growers bring up “defoliation”. No amount of nutrients will help the plant grow, unless they are first processed through the leaves. Only then, may mobile nutrients, commonly called "plant food” continues to the buds, for growth. The real name for plant food is called “photosynthate”, but for the purpose and ease of this post, let’s use the term “plant food”.

Leaves" have two main purposes:

1st, You can thank the leaves themselves for 99% of all the uptake of water and nutrients. Plants have a very small chain of water molecules that stretch from root to leaf, within the “xylem” (the woody center part). This ionic chain phenomenon is referred to as cohesion, whereas the entire uptake, from root to leaf, is called “transpiration”. Water is basically the blood of the plant. If you cut any leaves off, you limit the plants resources of water.

2nd, Leaves make all the “plant food” that the plants use to grow, while managing waste (O2), through the stomata. The stomata are very small pore-like openings in the bottom of the leaf, which exchanges new CO2 and O2, and water evaporation. “Plant food” is made through a process called photosynthesis, with in the chloroplast. Leaves are like a big food engine, but instead of 2 fuels like a car (gas & O2), leaves have 3 fuels (CO2 & Nutrients & PAR).

So, why remove them?

I’ve never liked the term of “defoliation” as it means “to strip (a tree, bush, etc.) of leaves”, implying all of them. I prefer to use their relative nick-names, “lollipopping”, “schwazzing” or even “pruning”, to limit confusion. These methods are not something I would promote anyone who desires larger yield, especially outside in full sun or if using auto-flowering seeds. Realistically, removing “any” healthy mature leaf will hinder growth & yield. A good rule of thumb would be to let the plant itself decide naturally what she wants to keep.

Distinguishing the different terms of training, or pruning growth is also a factor. Pruning a branch off the main stem, to manipulate growth direction, is not defoliation. Defoliation includes only leaf matter.

Growth “time span”, is also something that plays a roll. Depending on the cannabis grower’s view, any plant manipulation while in vegetation cycle may not be viewed as playing a role in final yield, while referring to defoliation. As an example, a farmer could prune half the vegetation off in veg cycle, but gives enough time for the vegetation to grow back, before entering into flower. If the factor of “time” itself is removed, the outcome of yield could be viewed differently. This does not apply to Auto Flower strains, as the cycles are fixed, and not based on light cycles.

Understanding what the flower actually is, is also important. Cannabis, being an “incomplete flower”, and a “raceme” type, generally has only male or female parts, where a complete flower has both. Nowhere within the flower itself, is there any leaves. Leave form around each flower. A “Raceme” is a flower cluster with the separate flowers attached by short equal stalks at equal distances along a central stem.

The “flowers” them self, do NOT require any light. No amount of light that’s exposed to each flower will help it grow any measurable amount, or yield more. It the physical features simply aren’t there for any measurable amount of photosynthesis to occur.

In botany, a “bud” is a knob-like growth on a plant that develops into a leaf, flower, or shoot. Only in the cannabis world does it mean “flower clusters”, in a slang fashion. Realistically, referring to a “bud” would be closer to saying “cola” or “meristem”, as it contains flower and leaf, and usually the primary growth area of the shoot.

Where/what is this sink?

“Sinks cells” are areas of new growth with low osmotic pressure. Leaves are areas of high pressure, hence why “plant food” or “photosynthate”, flow from high pressure leaves, to low pressure sinks; commonly called “osmosis”. Sinks can be in the roots or the shoots of the plant (new growth). After the plant food has been manufactured in the leaves, it enters into the phloem, starting at an area in the leaf called “source cells”. From here, osmosis carries “plant food” to its destination and use.

Now for an overall recap. Nutrients use the water to hitchhike a ride, up the xylem, to the chloroplast in the leaf. The leaf processes the raw nutrient into plant food. Then, plant food, enters into the phloem, and high pressure pushes it throughout the plant to areas of low pressure and use.

I do not recommend the removal of any healthy, mature leaf.

Good luck & happy growing


@GFDuke :+1: :+1:
My understanding from many agricultural studies on many different plants confirms all of this.
But there will still be those who think differently.

Ya folks! I’m keeping it bushy! Updated photos!


Also… I don’t smoke. I eat edibles… So the undergrowth goes into the butter!

It’s really like any other plant. Would you go out into your garden and trim all of the leaves off of your Tomatoes or any other plant? Would you trim all of the leaves off of your fruit trees or the flowers in your flower garden? The simple answer is no. But like other planting, you have to be mindful of spacing. Your plant in the picture are crowding eachother. Do you have another tent so that you can give them more room?

1 Like

Well I learned 2 things from this.

  1. I won’t take off unnecessary leaves

  2. I should of payed attention in school and gone to college :grinning:


This was a well-done, cogent description that should be made available to all growers.

I’ve harped on leaf removal as well as forcing deficiencies in flower being adverse to peak yields.

Well done sir! Bookmarking.


Agreed. I just posted a link to it in another thread today. Hall of fame post right there.


hey yall thanks for the feed back. it actually takes me a minute to place all the plants under the light after watering. they all are in perfect harmony. no buds or leaves are touching! takes about 3 hours to interlock them in perfect harmony… if you know what i mean :slight_smile:

1 Like

I don’t even try to move the plants anymore. Too old and too much arthritis.
I have a transmission fluid funnel and a stick of 3/4 pvc pipe and just aim it at the right spot to water.


I saw a side by side comparison of clones on another website where one tent got ‘trimmed’ and one tent was just let to grow as it wanted…https://www.growweedeasyDOTcom/summary-of-cannabis-defoliation-side-by-side-experiment .the end result was the trimmed plants had a bit higher THC content, higher yeild with better quality buds…the plants were grown in soil, not hydro…so which do I believe something that someone wrote above in this forum or something someone documented over a grow period with actual results posted…we all want to grow the best we can and I find that almost every day we find out something we did that is not necessary and something we haven’t done that is really needed…


that link doesnt work

I thought I had to write DOT for the .com to not offend the forum rules

nice try… but a 1 ounce difference doesnt prove anything… the phenotypes in each tent would make that difference… not the leaves

It’s actual science. Not just something that was just thought up. Go start a vegetable garden and trim all the leaves off of your plants. let me know how that works out for you.
I will say though that some stressing at the end of the plants life (the last 3 or 4 weeks) will increase it’s production of bud. As it see’s it as a threat and will produce a bigger thicker bud. some pruning might work in this way. But it doesn’t work when the plant needs it’s leaves during the grow cycle.


Its an interesting experiment. However its not what we mean when we see this topic posted.
Nobody here recommends letting the plants grow foliage to the degree in this experiment.
Neither do we mean defoliation in the manner he used. Those plants still have a large number of big fan leaves. In fact what is called defoliated in this picture is just what all of us do to keep airflow and plant health in good shape. I don’t know of a single grower here that would let the undergrowth get to the state of those plants he left unpruned. If anything I would call this a test of proper plant maintenance vs neglect. I would also like to know details of watering and feeding for each as they would be different due to transpiration. Even @GFDuke said to remove any unhealthy growth and this was obviously not done.
There is a balance to plant maintenance. I am not surprised by the test results in that link at all. But neither do I think its exactly what we are talking about. We all tend to the plants by removing parts to some degree. The ones on the right in this photo look like all the best ones we see on the forum. I never see ones like on the left.

This is what I would like to see tested vs a plant left with healthy foliage.


My brother trimmed one of his plants like the one on the bottom (behest my advice). The buds were small and airy. The plant stayed small as well. Like you said, plant maintenance is different from defoliating. And, we are talking auot-flowers here as well. They have to short of a life span to recover from such stress. Now, if they were photo’s then they would most likely be able to recover since they wouldn’t bud until you told them too.

1 Like

…I don’t think me or anyone else is proposing that you strip all leaves from her…but removing some leaves and branches will help most plants grow better in my experience .


That’s all just Maintenace. Not defoliating. I agree that some bottom foliage can be removed to help better the plants health. In fact in the grow facilities here thats how it’s done. But, in the grow facilities they grow photos not auto’s. You can Google picture of grow facilities to see how the maintain their plants and you will see how much they actually trim. Like this one.


:rofl: that’s the difference between them and me…I grow for quality not quantity…

1 Like