When to Prune Your Cannabis Plants

It’s finally time to harvest your cannabis plants, but when do you know when to prune them? Read on to find out the best time to prune your cannabis plants!

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Pruning your cannabis plants is an important cultivation technique that can help improve yields and ensure a healthier crop. Although it may seem daunting at first, pruning is relatively easy to do and can make a big difference in the quality of your plants.

There are two main times when you should prune your cannabis plants:

-When they are young and still growing
-When they are flowering

Each stage of the plant’s life cycle requires different types of pruning, so it’s important to know what to do at each stage. In this guide, we’ll go over everything you need to know about pruning your cannabis plants, including when to do it and how to do it properly.

The Different Types of Pruning

Topping, FIMing, LSTing, and defoliation are all types of pruning that can be done to cannabis plants. Each type of pruning has its own benefits and drawbacks, so it is important to know when to prune your plants and which method to use.


One of the most common pruning techniques used for cannabis is topping. Topping involves cutting off the main stem of the plant just above a node (a point where leaves branch out). This causes the plant to grow two new main colas (tops) instead of just one.

Topping is usually done early on in the vegetative stage, when plants are young and have not yet begun to produce flowers (buds). By topping early, you can encourage your plants to grow bigger and bushier, with more main colas. This can be beneficial if you’re trying to increase yields, or if you’re growing a plant that tends to produce small buds (such as certain Sativa strains).

Topping can be done more than once, but each time you top a plant, it will take longer for it to recover and start producing new growth. For this reason, it’s usually best to topping just once or twice per plant.


Fimming, or “FIMing,” is a type of pruning that is done to cannabis plants in the vegetative stage. It is similar to topping, except that instead of removing the entire main cola, only a portion of it is taken off. This leaves several small shoots that will grow into multiple colas. Fimming encourages lateral growth and can be done multiple times on the same plant.

Fimming is best done early on in the vegetative stage, before the plant has put all its energy into growing one large main cola. It can be done more than once, but each time you remove more of the main cola, you are decreasing the plant’s overall yield potential.


Main-lining is a type of pruning that is performed to encourage the growth of the main stem of a cannabis plant. This is done by removing all of the lateral (side) branches from the main stem, leaving only the main stem and the leaves at the top. Main-lining is typically done early in the vegetative stage, before the plant has grown too large.

The Different Stages of Cannabis Plants

Pruning your cannabis plants is important to ensure they are healthy and produce the highest quality buds. But when is the best time to prune them? It depends on the stage of the plant’s life cycle. In this article, we will explain the different stages of cannabis plants and when you should prune them.

Vegetative Stage

The vegetative stage of a cannabis plant’s life cycle is when it is growing and gaining size. During this stage, the plant will develop a strong root system and a dense canopy of foliage. The vegetative stage usually lasts for 4-8 weeks, but it can be shorter or longer depending on the variety of cannabis and the grower’s preference.

Cannabis plants can be kept in the vegetative stage indefinitely by giving them 18-24 hours of light per day. Once the plant has reached its desired size, the grower can begin to reduce the amount of light it receives per day, slowly transitioning it into the flowering stage.

Pruning during the vegetative stage is important for controlling the shape and size of the plant. It is also helpful for increasing air circulation and light penetration to the lower parts of the plant. To prune, simply remove any excess leaves or branches that are crowding other parts of the plant or obstructing light from reaching its lower levels.

Pre-flowering Stage

Pre-flowering stage is the growth stage that occurs after the vegetative stage and before the plant starts to produce flowers. During this stage, the plant will start to develop reproductive organs (such as pistils and stamens) but will not yet produce any flowers. This stage usually lasts for 2-3 weeks, although it can vary depending on the strain of cannabis.

After pre-flowering, the plant will enter the flowering stage, where it will begin to produce buds.

Flowering Stage

The flowering stage is when the cannabis plant grows its buds. This is the most important stage for growers because it is when the THC and CBD levels in the plant are at their highest. The flowering stage can last anywhere from 6 to 16 weeks, depending on the strain of cannabis. indica strains tend to have shorter flowering times, while sativas have longer flowering times.

During the flowering stage, the cannabis plant will need more light than it did during the vegetative stage. The best light source for this stage is either a high-pressure sodium (HPS) lamp or a metal halide (MH) lamp. These lamps emit a lot of light in the blue and red parts of the spectrum, which is what plants need during this stage.

Cannabis plants will also need more nutrients during the flowering stage. The best way to provide them with these nutrients is through a combination of fertilizers and soil amendments. Fertilizers should be applied every 2 weeks, and soil amendments should be applied every 4 weeks.

One of the most important things to remember during the flowering stage is that plants need to be pruned regularly. Pruning helps remove any dead or dying leaves and branches, which allows the plant to focus its energy on growing buds instead of maintaining leaves. It also helps increase air circulation around the plant, which helps prevent mold and mildew problems.

Pruning During the Vegetative Stage

One of the best times to prune your cannabis plants is during the vegetative stage. This is because the plant is growing rapidly and can easily recover from any pruning that is done. Pruning during the vegetative stage will also help to shape the plant and encourage it to grow in the desired direction.

To prune during the vegetative stage, simply remove any leaves or branches that are growing in an unwanted direction. It is also a good idea to remove any leaves or branches that are damaged or diseased. When pruning, be sure to make clean cuts so that the plant can easily heal itself.

Pruning During the Pre-flowering Stage

Pruning your plants during the pre-flowering stage can be a little tricky because you need to be careful not to damage the plant or remove too much foliage. However, if done correctly, pruning can help encourage new growth and improve the overall yield of your plants.

The best time to prune your cannabis plants is during the pre-flowering stage, which typically lasts for about six weeks. During this time, you should remove any dead leaves or branches, as well as any leaves that are yellowing or browning. You should also thin out the canopy so that more light can reach the lower leaves.

To prune your plants, you will need a sharp pair of scissors or pruning shears. Start by cutting off any dead leaves or branches. Then, thin out the canopy by removing some of the larger leaves. Be sure to make clean cuts so that you do not damage the plant.

After you have finished pruning, it is important to fertilize your plants so that they can recover from the stress of being trimmed. Use a high-quality fertilizer that is designed for cannabis plants and follow the instructions on the package carefully.

Pruning your cannabis plants during the pre-flowering stage can be a little tricky, but it is worth it for the improved yield and quality of your plants. Be sure to use sharp scissors or pruning shears and make clean cuts to avoid damaging the plant. Remember to fertilize your plants after you have finished trimming them so that they can recover from the stress of being trimmed.

Pruning During the Flowering Stage

Pruning during the flowering stage should only be done if absolutely necessary, as it can shock the plant and cause stunted growth. If you do need to prune during flowering, only remove a small amount of leaves and wait a few days to see how the plant responds before removing any more.


As you can see, there is no “perfect” time to prune your cannabis plants. It really depends on your personal preferences and growing goals. However, we generally recommend pruning in the early stages of the vegetative phase (around 2-4 weeks after germination), as this will give your plants plenty of time to recover and start producing new growth.

Of course, if you want to wait until the flowering phase to start pruning, that’s perfectly fine too! Just remember that you may need to do more pruning in the early stages of flowering if you want to control the size and shape of your buds.

Regardless of when you decide to prune your plants, always be sure to use sharp, clean shears or scissors. This will help prevent disease and infection, and will also make it easier for your plants to heal themselves after being pruned.

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