Topping is a central and fundamental plant training practice. It enables you to train your plants to grow horizontally and make the most efficient use of the light. If you are new to cannabis cultivation, topping cannabis plants is a vital step to maximize the overall quality of the yield. It is a tool that helps to control the overall shape of the plant – by redirecting the growing tendency from vertical to lateral.
The process of topping cannabis plants is relatively simple and uncomplicated. It involves cutting off the top part of a plant during the vegetative phase to encourage it to grow more laterally. Cutting off part of your plant might seem like an odd thing to do, but in the long-run, this works to produce large yields of great quality.
When To Top Cannabis Plants
When to top a cannabis plant is a big question and it does not always have a perfect answer. This is because species vary, growing environments vary, and of course, there could be mutations – planned or accidental. Those factors all weigh in to determine “when” is the best time to top cannabis. However, the topping is also planned, and you manage a lot of what your plants do by controlling soil, water, and light.
You don’t want to top a cannabis plant too soon. The plant must be able to handle the pruning process. A cannabis seedling can range from 1-2 weeks old, and you would not want to top the plant at week three. It would likely not survive, even though at week three, it should be in the vegetative stage of its development.
A good rule of thumb is to count the nodes. A node is a junction on the stem where branches grow from the main stem, and cannabis plants tend to node in pairs. The spacing between nodes is called the “internode.” The internode is the stem that grows from one node to the next. Indica plants tend to have very short internodes, as these plants are short and squat. Sativa plants, which are taller, have a longer internode.
We generally recommend that you wait until your cannabis plants have 6 nodes before topping them. This ensures that they get adequate stem and root development before the shock of topping. Because of the nature of how auxins behave and what is most efficient for light, we recommend topping the plant above the 4th, 5th or 6th node.
Topping higher than the 6th node, can lead to uneven dominance and a pattern that prioritizes vertical growth. Manifolds and Mainlines are often topped down to the third node, but if you are not following those training practices, topping below the fourth node will leave too few branches to develop.
How to top cannabis plants
Topping a cannabis plant is a high-stress training (HST) method that works best when the plant is developed and can withstand a drastic change.
For the first topping, a good rule of thumb is to cut the plant above the 5th node—this will give you enough branches on the bottom for the plant to bush out properly.
For subsequent toppings on the same plant, cut each branch above the second or third node, to allow the plant to grow out properly. These toppings are more subjective however, and will depend on how much you want the plant to bush out and how big you want the final plant to be.
- Get your tools and disinfect. You’ll need either a pair of pruning scissors or a razor blade. The sharper the better—you want to make one clean cut. The tool should be sterilized with rubbing alcohol to help prevent infections in the plant (this is very rare, but it doesn’t hurt to be safe).
- Decide where to make your cut. Topping will create two new stalks from where you cut, whereas fimming might create 3-8 new stalks.
- Monitor your results. With both techniques, you’ll see the plant direct more energy to the lower branches of the plants, and they’ll begin to catch up with the newly trained dominant stalk. It’ll take a few weeks for the plant to fully recover, at which point, branches can be topped again if you so choose.
The number one advantage of topping cannabis plants is the tremendous yield potential that the technique unlocks. In comparison with marijuana left to grow au naturel, topped cannabis plants will deliver a heavier harvest nine times out of ten.
Topping can be useful when your growing room isn’t very high. Especially Sativas grow very quickly and can become very tall. Since they don’t get very wide, you have to place many plants close to each other, so no light is lost. Light that doesn’t hit the leaves and falls on the ground is considered lost energy. By topping the plants, they will stop growing lengthwise for a bit, but they’ll mainly grow in width. You can then leave some more room between plants and still have a nice green blanket.
Lastly, topping spreads your risks. You get more main buds, and because they’re not as big, they’re not as sensitive to bud rot and/or other nasty diseases. Once again, this is a major advantage for outdoor plants. Especially because you can’t control the climate and your plants become sensitive to bud rot in the moist fall. Indoor growers could place some more plants without topping them to spread the risks.
- Are you searching for cannabis seeds? Check out our seed store – it’s well worth checking out!