When you think about growing cannabis, pruning and defoliating may not be the first things to come to mind. After all, growers work hard to get more plant rather than less, so cutting feels intuitively wrong. Besides, a robust marijuana plant hardly resembles typical pruning species like boxwood or a rose bush. Also, many growers consider pruning and defoliating cannabis plants unnecessary, or in fact counterproductive. The truth is, though, that pruning and defoliating cannabis plants can be rewarding if you do it right. Learn how and when to cut weed leaves for healthier, bigger plants in this blog.
The Benefits Of Pruning And Defoliating Cannabis Plants
Pruning and defoliation are techniques all gardeners use to shape their plants and keep them looking neat and tidy. Without pruning, plants can easily grow too big for their intended spaces, or they can push out neighbouring plants. When it comes to growing cannabis seeds, however, there are other reasons to consider pruning, and particularly the technique known as defoliation. A grower who handles it the right way can actually use the technique to improve their harvest.
Defoliation literally means removing foliage, i.e., leaves, from the plant. Removing leaves in the right place will allow more light and air to reach other parts of the plant, including the buds and lower foliage. Especially for growers with limited (indoor) space available, learning how to defoliate is really worthwhile. It allows you to make the most of a minimal number of plants. The technique is not very much suited for beginners, however. Defoliating weed plants takes some careful planning. It’s also crucial to proceed with caution if you want to avoid damaging your plants. If you’re not sure whether defoliating is your kind of thing, don’t worry; cannabis plants can manage perfectly well without defoliation or pruning, whether grown indoors or outside.
Different Cannabis Pruning Techniques
Actually, pruning cannabis plants is too much of a catchall term for practical use. Growers have several different pruning techniques to choose from. Some of these are high-risk interventions, since they can easily damage the plant and cause stress as a result. These ‘high stress’ pruning techniques include fimming and topping, for instance. These involve removing the growth tips or cutting them in half to encourage production of more new growth tips.
Defoliating, however, can be considered a ‘low risk’ pruning technique, although stress and damage can only be contained by modest cutting and knowing when to stop. That’s why we’ve added a defoliation crash course below.
What Does Defoliation Mean?
Put simply, defoliation is the removal of leaves. Obviously, this isn’t a random process, but rather a matter of carefully and deliberately picking the right leaves to prune away. The goal is to create a stronger, healthier plant. Defoliating works by giving the plant a fair chance to direct its energy to the parts that need it most. Ideally, these are also the parts that growers like best – usually the buds.
Leaves dying off is a perfectly natural part of the cannabis growth cycle. By removing the leaves that are prone to fall off, you save the plant from spending valuable nutrients and energy in parts that it will shed anyway. Removing these leaves minimizes the effort your plant needs to grow. That means more energy is left to maintain healthy leaves and produce new ones. This is how defoliating cannabis plants can promote growth and production of new branches, which leads to new buds in turn.
The Best Way To Handle Defoliating
Defoliating cannabis plants is a useful technique for growers. However, if you’re not that experienced yet, it is best to start out slowly.
A few tips for beginners:
- Only remove the leaves that already look unhealthy (brown or yellow edges; dry and shrivelled leaves, or foliage damaged by predation);
- You can remove the big fan leaves from branches you have cut before, once you notice they start to grow new leaves. The older leaves will turn brown and die by themselves, eventually. That means you can safely remove them;
- As a general rule of thumb, try not to remove more than 10 – 15% of the total canopy.
If you plan to defoliate cannabis plants, always use the appropriate tools for the job. Don’t tear leaves off by hand. Use sharp cutters, shears, secateurs, or a pruning knife. It’s also generally a god idea to water plants right after defoliation and pruning, possibly adding some extra nutrients, but don’t take it too far. If used moderately, water and the right nutrition can help plants recover faster.
Defoliation: Advanced Grower Tips
These beginner tips can help encourage plant growth and promote better harvests. For advanced growers, however, defoliating cannabis plants can hold many more benefits. The technique enables directing growth, efficient use of lighting, and in doing so, substantially increasing harvest results.
Once a cannabis plant has matured sufficiently, its larger fan leaves can be pruned away. These cast a lot of shade, preventing the light from reaching the lower strata of foliage. Next, you can remove the leaves growing near the main stem, which can also obscure the buds from the light. And finally, you can cut away yellow aging leaves. The trick is to remove enough leaves to maximize the profit for your plant (increased availability of light and improved air flow), without going too far and undermining the plant’s health. If you get it just right, your plants will have more energy left to invest in bud growth, resulting in larger, more compact colas.
When To Start Pruning And Defoliating Cannabis Plants
Never start defoliating cannabis plants before they enter the second week of the vegetative phase, or growth stage, of their regular life cycle. At that point, you can already see the final shape of the plants shine through. If you are growing indica weed, it’s best to wait another week, as these tend to grow at a slightly slower pace than sativas do. You can continue defoliating cannabis plants up until the second week of the flowering stage. After that, pruning is not advisable, as the plant will not have enough strength left to recover.
Pruning And Defoliating Cannabis Plants: Know What You’re Getting Into
So, all things considered, is defoliating cannabis plants a good idea? The tricky bit with this technique is the lack of solid general guidelines. It is basically a matter of developing some grower’s intuition, which results from carefully observing your plants’ behaviour. If you’re just starting out (i.e., if you have less than three grows under your belt), it’s probably best to leave it alone. Take the time to get to know your plants, and learn to recognise a healthy, fully grown cannabis plant first. If you do have a bit of experience, then pick only a few plants to practice your defoliation skills. That way, if anything goes wrong, at least you’ll still have a few healthy specimens left.
Growers who are keen to learn more about the various techniques available for improving harvests should have a look at our other Grow Blogs. Interventions such as FIMming, supercropping, or low stress training can all yield interesting results. Some of these techniques are very easy to use, even for novice growers. Of course, combining techniques is an option too, as long as you don’t stress out your plants too much. Stress can seriously impair a plant’s growth, flowering, and harvest potential as well as turn it into a hermaphrodite, so whatever you do, proceed with caution and use the advice of experts to your advantage!
Disclaimer: Local laws and legislation on cannabis cultivation and germination of seeds vary between countries and states. Amsterdam Genetics products and information are exclusively intended for use in areas where such use is fully legal. Check your local rules; do not act in conflict with the law!