Trimming your plants can be necessary in almost every type of garden. Trimming foliage off of plants can help prevent or cure diseases, improve air flow, or reduce need for fertilization. In cannabis grows, though, it’s a trick used to increase yields. There are two main styles of trim you can use with your cannabis plants: topping and fimming. Both can help your plants, though the most important thing is to figure out which one will work best for your garden.
Both of these methods work by triggering the growth of multiple stems, or colas. Cannabis naturally grows in a single cola, but this results in an uneven harvest. Buds at the top of the plant are bigger, because they receive more light. By trimming your plants, you get multiple colas, and more of your bud is grown at the top of the plant. This means that you get a better harvest and buds of roughly even sizes.
Cannabis topping is the process of cutting off significant portions of your plant in order to spur the growth of multiple new colas. When a cannabis plant loses the top of a stem, it grows two new stems to compensate (sort of like those limb-regenerating monsters in horror films). So, topping results in more colas, and more flower nodes that can easily reach the light. This high-stress training technique is great for getting the most bang for your buck out of every plant. It’s also good for controlling plant height if you have a shorter grow tent.
How to Top Cannabis
Topping cannabis is relatively simple. The most important thing is to wait until your plant has enough leaves to survive topping. In general, it’s a good idea to wait until your cannabis plant starts growing its seventh set of leaves. This is a sign your cannabis plant is strong enough to survive the shock of topping.
When you top your plant, get a pair sharp scissors or a plant trimmer. Leave at least four sets of leaves to make sure your plant will continue to have enough energy. About an inch above the fourth node, cut the top of the plant off. In a week or so, you should have two healthy new colas growing from that one stem.
Some growers repeat the topping process until they reach eight colas. This is about the most that a cannabis plant can manage, and it may require support such as a trellis or ties. This method is great for growers who want to instigate as much stress on the plant as possible, to trigger more growth.
Fimming is less stressful to your plants than topping. Instead of cutting off significant growth, you just remove small new growth before it can expand. Fimming also triggers more than two new colas, so it expands your plant more quickly. The downside is that, since you aren’t cutting off a portion of the plant’s total height, your plants will grow taller.
How to Fim Cannabis
This method is most easily done by hand, with your fingers. To fim a plant, you’ll want to wait until there are at least four or five sets of leaves. Then, when new growth appears above the top set of leaves, you simply pinch it off. Soon you should see multiple sets of new growth appear from the point where you pinched off the growth.
This method is great for growing bushy plants, but the plants will be bigger in general. Plants that have been fimmed almost always benefit from low-stress training as well, because bushy plants can sometimes block out light to their own colas. Fimming is great if you don’t mind height or if you loathe actually cutting your plants.