Topping cannabis plants is a well-known method used by experienced growers to increase the number of buds on one plant. It is a simple and above all cost-effective way of stimulating a higher yield with minimum investment. But what exactly is topping and how do you top a weed plant?
Topping Cannabis Plants
Topping is an old and proven technique, applied to a number of different plants. Take a boxwood for example. To ensure a full and thick boxwood hedge, this plant has to be trimmed down once or twice a year. For every branch that’s cut off, at least two new ones appear. Filling up the bush until it becomes impossible to see through it, be it for privacy or decorative reasons.
Obviously cannabis plants are topped with a different motive; though the technique stays unchanged. Pruning the main branch of a weed plant gives the underlying side shoots the opportunity to take over.
So one branch turns into two, giving you not one but two main colas. And instead of focusing all energy on one tall main cola, the energy is divided to the sides of the cannabis plant. Ensuring more ‘lateral’ growth, so a wider and bushier specimen. Moreover, this can be done with all branches on the cannabis plant, not only the main one.
Why Top Weed Plants?
Pruning a weed plant’s main branch doubles the amount of growth tips it can support. Naturally, this also increases the topped plant’s yield in comparison to a cannabis plant that is not topped. And although the two new buds are smaller than the original bud could have been without topping the cannabis plant, their total weight should be higher.
Topping cannabis reshapes the plant in a way that greatly benefits the light distribution. Cutting away one tall branch for several new ones at the same height, ensures lowers (buds on lower branches) get more light too. Considering light equals weight when it comes to cannabis cultivation, this is definitely one of the main advantages of topping weed plants. As you might have guessed, increasing yields is the most important reason for cannabis growers to top their plants.
Another big reason to top your cannabis, is height-management. Logically, the two new branches do not grow as fast as the one would. Topping a weed plant divides the growth of one branch over multiple ones. Making the plant grow less in height, but push more energy into growing wider. This is very convenient for growers, especially for indoor grows in confined spaces. Height-management and wider development is the second biggest reason to top your cannabis plant.
When To Start Topping Cannabis Plants?
As you may have expected, you can’t randomly start chopping away at your cannabis plant to top it. It is advised to wait until it has enough side branches to form new buds. These side branches sprout from the nodes of the plant (see below). This also allows for the plant to grow mature enough to quickly recover from the stress it encounters. No matter how well-performed, topping always remains a stressful event for cannabis plants. Too much stress can turn them into hermaphrodites, or worse, ruin them completely.
If even mature plants can turn hermaphrodites after the stress from topping. Imagine the harm it would do to a seedling with just 3 – 4 side shoots. Besides the possible stress, the (still baby) plant would need too long to recover from the operation for it to be profitable at all.
For the best results, wait until the plant is big enough to have developed a substantial root system. The bigger the roots, the less time a cannabis plant needs to recover from topping (or any other stress causing factors). So whatever you do, make sure your plant has at least developed three healthy nodes; but preferably more.
How To Top Marijuana
The main danger in topping marijuana plants is going too far. In other words: knowing how to top is knowing when to stop. To determine how far to prune a cannabis plant, it is important to know why you’re topping it. If you’re topping your weed to simply get two buds on the site where you used to have one, it’s best to leave as much from the top-growth on the plant as possible. Wait until the plant has around four nodes and cut the plant off high at the stem – to only take off the top part of the growing point. This ensures a quick recovery while doubling the growing points.
Some growers like to cut back their plant by more than one node, to create a firm base and bring down the height of the plant. This can be handy when you have only a limited space to grow in, indoors, but still want a firm stem and healthy root system before you switch to the flowering stage. This is sometimes used with mainlining, a variation of low stress training (LST) methods similar to Sea Of Green (SoG) and Screen of Green (SCRoG) techniques.
Mainlining: Topping And Low Stress Training Combined
In mainlining, growers us topping as the starting point of low stress training (LST). First, the growth tip is cut as with regular topping. Then, once the plant has recovered from the stress, the two new shoots are bent sideways, using special benders or wire. This spreads out the canopy, providing better circulation, allowing more light to reach lower branches, and ultimately supports growth of more buds on the newly created side branches.
The Limits Of Topping Cannabis Plants
It is important to remember that the more you cut away, the longer the plant needs to recover. When applying this technique, make sure the plant is mature enough to handle the stress. There are also certain chemicals to help the plant recover faster and eliminate the chances on developing hermaphrodite cannabis plants. Ask for them in your local gardening store or grow shop.
Not all cannabis plants tolerate stress equally well. In addition, topping takes a bit of finesse – it’s something you’ll just have to learn by trial and error. Once you’ve got the hang of it, though, you’ll find it is one of the easiest ways to improve the results of your grows, whether indoors or outside. Another variation of this technique is known as FIMming. Here, the growth tip is cut in half. This creates extra stress, but it can trigger plants to grow up to four new branches instead of just two. Read all about FIMming in this dedicated grow blog.
Also interesting: ‘How To Spot: Male, Female and Hermaphrodite Cannabis Plants‘
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!