Topping is a technique in horticulture in which you cut off the top part of a plant to halt its upward growth in order to promote lateral growth in the lower branches.
Although it may seem strange to cut off and throw away part of your cannabis plant, rest assured, topping is an essential step in keeping your plants healthy and getting quality yields.
This bushy shape is also important for a plant to receive light more effectively in a couple ways. It allows light to hit the plant more evenly—because the plant is more wide than it is tall, all of the bud sites will receive a more equal amount of light.
Topping or fimming a cannabis plant is a high-stress training (HST) method that works best when the plant is developed and can withstand a drastic change.
Topping is done during the vegetative cycle to help redistribute growth hormones from the main stalk to new offshoots and stalks farther down the plant. Topping and fimming will create an even canopy as the growth hormones are distributed to all the developing stalks and colas.
We’ll dive into topping, as well as a similar plant training technique popularly called “fimming” or “FIMing” (short for “f**k I missed,” if you’re wondering), something that started as an accident but is also useful in the right circumstances.
In time, these side branches can also get topped, which will created more side branches and make the plant bush out even more. Doing this will also create more bud sites on branches and therefore increase your yields.
If left to grow on its own, a cannabis plant will grow vertically, focusing its energy on one main stalk. The result is one long dominant cola with smaller stalks surrounding it. These smaller stalks will produce small, larfy buds that won’t be that good and the overall size and yield of the plant will be small.
A single plant can get topped a number of times, each time creating more branches and making the plant’s shape bushier.
Topping your cannabis plants is essential for promoting quality growth. Read about why it’s so important and learn how to top or FIM your plants.
In the diagram below, you can see that the natural plant (left – completely untrained) has less parts of the plant in the area with the best light level. As a result, this plant only has one main cola, and the rest of the colas are much smaller because they are further from the grow lights.
Less Powerful Grow Lights – Grow lights like CFLs and fluorescent lights have a “sweet spot” that is only a few inches away. The further you get, the less light your plants get. These types of lights can grow cannabis plants, and may be a good choice for some growers, but with less powerful lights, it becomes even more important that you learn how to train your plants to grow short and wide with many colas. Little weed plants are the best way to take advantage of CFL grow lights! Luckily the methods on this page like topping, FIMing, SoG, ScrOG, main-lining and more will give you the tools you need to get the most from your grow lights. By using plant training techniques, it becomes possible to harvest ounces of bud even from relatively small grow lights.
FIMing – A very closely related technique to topping. The idea of FIMing is to damage or “shave” the top of the plant instead of removing it completely. This can accomplish many of the same goals as topping, but has less of a chance of stressing the plant. The downside is it’s more likely to fail at actually breaking apical dominance (plant may still tend to grow one main cola).
Notice how the plants that get the most direct sunlight grow the biggest
Usually, growers will use more than one of these types of training because they can complement each other, but it’s also possible to use just one and not any others. For example, when growing auto-flowering strains you can’t manipulate timelines and it’s generally advised not to damage the plant since they have such a short life and that could result in stunting. So for auto-flowering plants, the main option is just bending and securing.
This is a huge part of why it’s important to understand how far away your lights need to be, depending on what type of light you have.
Read the complete article on Screen of Green.
This strategic defoliation exposes all the newly forming buds to light and air right when they’re at their most crucial stage of development. Because of how cannabis (a wind-pollinated plant) buds reacts to light and air, this dramatically increase the size and density of the buds as long as you take off the right amount of leaves at the right time (overdoing this or doing it too late in the flowering stage can do more harm than good!). It’s also very important to note that defoliation should only be done to indoor-grown plants, and even then only plants that are healthy!
Many indoor and outdoor cannabis growers prefer to keep their plants relatively short, growing bushy and wide instead of tall and thin. Keeping small plants helps make sure each plant gets plenty of light – light is like “food” for your plants, and providing the right amount of light will give cannabis plants the energy to grow.
Get a summary of all the most common plant training techniques that growers use to increase their cannabis yields indoors!