Growers often consider autoflowers to be extremely fragile strains that do not do well under high and low stress training techniques. However, that was before breeders started to produce better genetics that could withstand and even benefit from these techniques.
Defoliation is a fantastic way to increase the overall health, yield and potency of the plant, but it must be done correctly and at the right times. It is particularly important to know when to defoliate autoflower plants and how far you can go without causing stress.
Schwazzing or extreme defoliation is also another point that growers often wonder about in the context of autoflowers. In this article, we will cover all the main points of how to defoliate autoflower cannabis plants. So come along, let us dive into the defoliation of autoflower crops, how to do it and when to stop.
What is autoflowers defoliation?
The term defoliation means the systematic removal of foliage from a plant. In the case of cannabis, we only remove the fan leaves that have either already started to die or are getting in the way of the plant’s growth. Cannabis, like most other plants, produce extra leaves to compensate for leaves lost to herbivores and insects.
Fan leaves are the energy generation centers for the plant. This is where the bulk of the photosynthesis happens and where most of the mobile nutrients – N, P, K, Mg and Mo – reside.
Thus, the plant always produces extra leaves to ensure an adequate supply. However, in controlled conditions with no pests these leaves become a drain on a plant’s nutrients and cause shaded areas that receive less light. So, we can help the plant out by removing them.
What are the benefits of defoliating?
Defoliating is done for multiple reasons, all of which contribute to the steady and distributed growth of the buds and overall plant. The core principle of defoliation is to allow more light and air to enter the plant from every direction so that all bud sites (where the flowers will grow) get enough room to breathe and receive light energy.
This prevents uneven growth and maximizes the growth potential for each plant. As a result, all bud sites end up producing to their maximum capacity generating bigger yields. However, it is important to take it slowly and learn to read the response of each plant carefully when carrying out defoliation. Each strain and each plant will react differently, so you must be careful and moderate your efforts to produce the best results.
Defoliation also prevents infestations and mold. There is no dark place left for bugs to hide, so they will find it difficult to make your plant their new home. With no space where moisture can stick around, there will be no wet spots for mold to develop in. This is how defoliation can also help you to manage the health of your plants.
Summary of defoliation benefits
- Increases yield
- Improves airflow
- Improves light and nutrient distribution to buds
- Reduces risk of mold developing
- Reduces risk of pests or disease
When should you defoliate autoflowers?
Understanding when to defoliate autoflower plants is a very important part of the process. The best time to begin is during the vegetation stage, which is normally between weeks 3 to 5. Around week 3 is the ideal time to give your plant the first trim. The plant still has around 6 to 7 weeks of growth left and about half of those will be spent in flowering mode. So, this will allow the plant to recover fully from the stress of losing those fan leaves.
Heavy defoliation can be performed around week 3 and 4 and it should ideally be done only once. Although if the plant responds well you can try it a second time, but no more than twice in the entire lifecycle of the plant. If there is a drastic loss, the plant may go into shock, and this could cause it to not fully recover in time before it starts flowering resulting in smaller yields.
Defoliation just before or during the first two weeks of the flowering stage is okay but never beyond that because the plant will not have enough recovery time. During the stretch phase, the plant will still be putting a lot of energy into growing its foliage. So, this is a great time to guide its energy usage via defoliation. It will likely lead to increased yield and potency, even if you haven’t defoliated before this phase.
DO NOT defoliate during the transition phase to flowering. Do it before the plant switches and then wait for the stretch period to commence before you do it again. The transition period is a delicate one, so leave the plant alone during this time. Autoflowers will usually go into bloom around weeks 5 to 6.
One last trim, which may even be considered a wet-trim, can be done right before harvest. Do this one or two days before harvest, but no earlier than that. Your flowers may become more potent when you defoliate in this manner. But since the plant is not growing anymore and you will chop it off right after, this is more like preparing your bud for the drying and curing phases while it is still on the plant.
Risks of autoflower defoliation?
There are several risks associated with defoliation and they are all related to incorrect timing and removing too many fan leaves. The main principle of defoliation is to be moderate. As explained earlier, fan leaves are the energy production units of the plant. Take too much off and the plant will not have enough energy to do recover. So, it might go into shock and a female plant might start producing male flowers, turning the plant into a hermaphrodite.
Too much defoliation can also happen when you do not give you plant enough time to recover between sessions. Allow at least one week between each session so that the plant has enough time to get back its growth spurt and heal its wounds. If you take off too much in this manner, it may stunt the growth of the plant.
Defoliation done beyond the stretch period during the flowering stage is also a bad idea. At this stage a plant does not produce any more fan leaves and so removing them could reduce the amount of photosynthesis and therefore nutrients that reach the buds. As a result, you may get smaller lower quality buds, or the flowering period might extend a few weeks while the plant recovers from the loss.
So, it is important to understand how and why defoliation works and how each plant responds to this method. Once you get a feel for it, it will be hard to go wrong.
How many fan leaves should I remove from my autoflower?
This is a critical part of understanding how to defoliate autoflower plants correctly. A simple rule of thumb – never take off more than a third of the leaves in a single session. You should always start at the bottom of the plant and work your way to the top and only trim those leaves that have stopped growing.
- Look for leaves that are already dying, these need to be removed first. Then look for overlapping fan leaves where the light is not reaching the inner or lower parts of the plant. In such a case, remove the upper leaves so that air and light can enter.
- If one upper branch is shooting straight up and casting shadows on all the others, you can easily remove the leaves from that branch to slow it down. This will allow the rest of the plant to catch up to it and thus promote an even growth. Our goal here is to have a light, airy canopy where every part gets an equal amount of light and air or as close to this ideal scenario as possible.
- Be selective and critical, err on the side of removing less rather than more unless you are very sure of what you are doing. It is okay to experiment as a tool for learning but always carry your lessons forward to create better yields for future growth.
Can you use Schwazzing on autoflowers?
Schwazzing is a form of extreme defoliation that was made popular by a book called Three a Light, referring to a yield of 3 pounds per 1000w light. It was developed as a technique for photoperiod strains and was not meant for autoflowers. However, extreme defoliation is still done by some growers in the hopes of achieving the same results from super-cropping their autoflowers.
This has always given mixed opinions and thus should be avoided by new and amateur growers. You must be really in tune with your plants to push them to the extremes of schwazzing. Even then, there is not much evidence to suggest that this really does help in increasing the yield of the plant or the potency of the buds.
Autoflower leaf tucking as an alternative method
Leaf tucking is a safer, low stress training alternative to defoliating autoflowers. Here, we take two opposing fan leaves and tie them together to create more space within the canopy. Since there is no open wound on the plant, it slowly adjusts to the new situation without experiencing much stress. This helps us achieve our goal of guiding the energy of the plant towards an even distribution of the canopy without risking any shock or extending the growth/flowering period.
Leaf tucking just needs a little extra care when it comes to moisture retention because the tied-up leaves will create a pocket where moisture might be retained.
Most professional growers will use very minimal defoliation to achieve the desired results. In most cases, the plant will not look drastically different after a session. This is because they are removing leaves very selectively and with extreme care. There is a balancing act between releasing more energy for the bud sites and taking away the plant’s source of nutrients.
Remember to feed the plant adequately as you go through the process so that there is no nutrient deficiency resulting from the loss of leaves. However, if you are being minimal to moderate about it, it might not need much modification in the feeding pattern. Always be vigilant and observe the plant because each one will be different, even if they are the same strain.
In any case, don’t be afraid to experiment with your grow and most importantly have fun doing it.