by Nebula Haze
First of all, I want to thank the thousands of you who have been writing in with feedback, testimonials, questions, and plant doctor submissions. We are totally overwhelmed by the positive response we’ve been receiving.
Many of you have written in with questions about marijuana defoliation as a free, simple way to increase your yields. Many of you have also written in with pictures showing your results with defoliation.
Sirius and I decided we needed to revisit this topic and make sure the whole community gets all your questions answered about defoliation.
Click here to read our original newsletter article about marijuana defoliation:
What is Marijuana Defoliation and How Does it Work?
Marijuana defoliation means to strategically remove leaves in the Vegetative and Flowering stage to control growth and force plants to grow short, wide and bushy.
In the Flowering Stage, strategic defoliation also seems to actually increase size of buds while allowing lower bud sites to get light and develop. Overall, a properly defoliated flowering plant will get higher yields than one that is allowed to keep all her leaves.
It’s not all fluffy clouds, though. There is risk involved with marijuana defoliation. A defoliated plant is less hardy, and has a harder time recovering from problems than a plant with many leaves to spare.
If too many leaves are removed, or if the plant isn’t healthy, a defoliated plant can get sickly, which will severely reduce your yields.
Therefore it is recommended that most growers DO NOT defoliate their plant until they’ve had a few successful grows under their belt. Especially do not defoliate during the flowering stage on your first grow, as the flowering stage can be a rocky time for new growers, and you don’t want to throw this into the mix.
For a beginner-friendly free marijuana growth control technique, take a look at this tutorial on supercropping:
Yet for experienced growers, I highly recommend experimenting with defoliation – at your comfort level – and be amazed at how something so simple gives you so much power over the shape of your plant during the flowering stage, and increases yields so dramatically during the flowering stage.
Remember, a defoliated plant needs less nutrients!
So to answer the most common question about marijuana defoliation, which was recently asked by Sensimilla (@Dank_Racks) on twitter…
@growweedeasy I gotta ask. I know you defoliate etc. but the leaves are used for plants energy etc. so why take good leaves off?
Since Leaves Are Used For Energy, How Can Taking Leaves OFF the Plant Actually Increase Yields and The Size of Buds?
First, a quote from Keef Treez, a respected marijuana grower who’s been growing for over 30 years and has dedicated himself to teaching others the shortcuts he’s learned to producing huge yields on short, indoor plants.
“…I believe what’s most important is studying how the plant actually grows, instead of assuming she grows how we think she should grow. Real experimentation and unbiased observers are the only way growers are going to learn how to get the best yields for the amount of time, money, and effort.”
So in short, as I told Sensimilla:
@Dank_Racks I’m not sure exactly why, but if you expose buds to direct light and air, they explode in growth, like this pic.twitter.com/WnXImciW
Ok, so I know that’s still kind of a cop out answer.
Let me just give you a little more proof about how well defoliation works, then I will reveal exactly why it works:
So first, here’s more proof:
Dj FarrOut (@djfarrout) said about defoliation: “i have been doing this for 6+ years and it goes against most everything you hear/read”
Peter Parker on facebook says about defoliation:
“no brainer,less shade=more light=bigger flowers, and as the plant isn’t keeping those leaves alive, more energy goes into the main reason we grow”
“Joy” says in response to our popular June issue on marijuana defoliation: “Do you find yourself almost “addicted” to the growing of this wonderful plant? The way it responds to things like this defoliating is so fascinating.”
Keef Treez “The Defoliator” says: “I’ve been defoliating intensively for 30 years. I am now training plants to be 32″ tall and 32″ round and yielding 250-400 grams under 400 watt lamp.”
Nebula Haze from GrowWeedEasy.com: Yes, that’s right, he said 8-14 OUNCES of buds of marijuana harvested off each short, easy-to-manage 32″ tall plant, using just a regular 400 watt HID grow light.
In addition to the great feedback, I’ve personally seen how well defoliation works, yet I was still fuzzy about exactly why it works as well as it does.
I knew it has to do with the physiology of marijuana plants, and I made it my mission to go and and research exactly why defoliation works so well.
What I found out surprised me…
Why Defoliation Increases Bud Size and Yields
Now, defoliation is known to increase yields in other flowering plants besides marijuana, and been proven to increase yields for crops such as cowpeas, which experience significant increases in yields when up to 50% of their leaves are defoliated during their flowering stage… (source)
Now some plants are able to recover fine after being defoliated, and some are completely intolerant and will die. Marijuana and its cousin hemp are hardy plants that generally tolerate defoliation well.
Almost all plants have to deal with herbivores in the wild. I know my cat will eat marijuana leaves if he can get to them! This tendency for leaves to be eaten may be part of why some plants are so resilient to defoliation and may even react favorably to certain types of defoliation.
According to J.H. Richards, of the Department of Land, Air and Water Resources, from the University of California explained in a paper back in 1993 that after a “transient period of one to a few days,” plants that have been defoliated go through a second phase that includes a “readjustment of physiological activity and the plant morphogenetic integration that occurs over several weeks.”
He says, “the amount and type of tissue removed, and when the loss occurs in relation to plant development” are the biggest factors that determine how the plant will react.
I believe at least part of the reason defoliated marijuana plants get higher yields may have something to do with compensatory photosynthesis:
J.M. Kilnet said of tomatoes: “Defoliation experiments showed that there was a flowering-inhibition by young leaves. Removal of these young leaves, especially those which were produced just before inflorescence initiation, promoted flowering. It is assumed that defoliation acted by removing the primary sinks for assimilates.” (Source)
In other words, the presence of young leaves seems to STOP the growth of flowers in tomato plants, and so removing these young leaves increases flower production, especially when they’re removed just before flowers start growing.
According to an article published in Photosynthetica, Volume 50, Number 2 (2012), “Defoliation could be used to manipulate source-sink relations by removing lower and senescing leaves to obtain greatest photosynthetic capacity and efficient carbon and nitrogen metabolism under optimal and stressful environments.”
One thing is certain, the relationship between leaves and plant production is NOT as simple as more leaves = more photosynthesis = more buds.
A whole lot of other processes are going on in the plant, and by properly manipulating the plant with defoliation, you can use these techniques to control growth and increase marijuana yields for free.
Defoliation in the Vegetative Stage:
Hey there, I love your site, it is really helpful! I have read through the defoliation section by Keef Treez and I wonder how those plants on the pictures get this bushy shape in the first place. I mean how do you train the clone in early veg state not to be like a xmas tree, but instead this multi-branch bush.. Or is it the snapping technique already? Or do you FIM-cut the early to-be-leaves? I would love to get an answer on this!
I actually wrote a full tutorial to answer exactly how to grow plants in the exact shape you want during the vegetative stage. It involves defoliation, FIMing, as well as a few other simple techniques.
Learn how to grow multi-branch bushy monsters in this tutorial about marijuana growth techniques for the vegetative stage:
About Nebula Haze
Nebula Haze founded GrowWeedEasy.com in 2010 after growing her own medical marijuana for 6 years in the California Bay Area. She has published dozens of growing articles in print and online and is dedicated to showing others how easy it is to grow marijuana indoors.
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