Gardeners of all stripes have used pruning to help keep their plants trim and tidy since the beginning of cultivation. A lot of plants can simply get too out of hand to deal with in any other way, and pruning is relatively harmless to the rest of the plant. With some plants, like marijuana and tomatoes, pruning actually serves the purpose of creating much higher yields. For cannabis growers, tidy plants and higher yields are two things that are certainly desirable. Below you'll find steps to for successfully prune marijuana plants throughout their life cycle.
1. Cut out lower, non-productive branches early. When the marijuana plant is still relatively small but in vegetative state, you can nix a few of the lower branches along with their attached leaves. There's nothing wrong with leaving those particular branches on the plant, but, when it comes time to flower the plants, they won't really produce much anyway. This little exercise also allows the plant to focus more on the taller and ultimately more productive branches. This will increase growth in the meantime and can potentially increase yield toward the end of the plant's life cycle.
2. Be Careful. When cutting the branches, especially when you prune marijuana plants at a young age, it's important to take great caution. Don't use dull scissors or a serrated blade, and certainly don't rip the small branches off with your bare hands. The last thing you want to do is shock the plant at such a young age. A nice, clean snip with some sharp scissors will do the trick.
3. Remove any dead or moribund leaves. As the marijuana plant ages, it's obviously going to get bigger. The upper leaves will start to fill out and form a canopy above the lower parts of the plant. Unfortunately for the lower end of the, those leaves will likely all die as a result of not getting enough light. Snipping them off even before they start to turn yellow has almost the same effect as clipping your fingernails. Except, in this case, the upper leaves will benefit from the missing lower leaves when you prune marijuana plants.
4. Keep the plants in check. If you're going indoors, then you are likely going to have some vertical (and occasionally horizontal limitations). Pruning can certainly remedy that situation without causing too much damage. If you're growing marijuana outdoors, the plant will have considerably more room to grow. While that's beneficial to some degree (because who doesn't like bigger plants?), it can get you caught. Bigger plants are naturally easier to see than smaller plants, and towering outdoor plants are a recipe for disaster (unless, of course, you have a highly-concealed location).
5. Top the plants. While it might seem counterintuitive to snip off the biggest branch (top cola), it can actually help you produce a much higher yield. The top colas actually have a chemical in them that restricts the growth of the lower branches, and, when you cut the top off, it allows the rest of the plant to flourish. The top colas are also pretty potent and you can use them as a test smoke if you want.
6. Don't force flowering right away. After you've topped the plant, you don't want to immediately start forcing the marijuana plant into the flowering stage. Give it some time to recover. Cutting the top cola late in vegetative growth is not the same as cutting a few shoots or small branches early on in the game. The lower branches and leaves will slowly start to work their way up to fill the vacancy left by the top cola. After about 4 or 5 days, you can start forcing the plants to flower, at which point you should be rewarded with a much higher yield for all your efforts.
7. Don't prune marijuana plants during flowering. Once the marijuana plant starts to flower, it's really a bad idea to try to prune anything else. Of course, if there are a few dead leaves or unproductive branches, you might be able to get away with it. But, any wholesale pruning during the flowering period is a bad idea. The plants are already growing rapidly and any extensive pruning to the plant will likely shock it. Some growers ascribe to the idea that putting stress on the plant will actually force it to grow faster to compensate. There's really not a lot of evidence to back this up and cutting up the plant too much will leave you with considerably less than you might have wanted.
Overall, pruning marijuana plants is a delicate process that should be treated with a lot of care to avoid any major setbacks. Do you have any pruning stories or advice? If so, leave them in the comments below.