Why, When, and How to Prune Cannabis Plants

Just like us humans could use a little self-care type of maintenance every now and then, our cannabis plants could use a tune-up too! As growers, it is our responsibility to have our plants looking, and most importantly, feeling their best.

That’s where pruning comes in. Your cannabis plant has finite energy and resources like nutrients and oxygen that it needs to grow, and it will distribute them to its various parts like the leaves, stems, branches, roots, and what we all want, potent, tasty buds! By removing the unnecessary parts of the plant, it now can redirect the energy it is saving to elsewhere more important.

However, pruning is considered HST (High Stress Training), which is usually when any part of the plant is cut or damaged, and these advanced techniques come with their share of risks, the most common being sending the plant into shock and becoming extremely stressed. In this blog post, we’ll cover the why, when, and how of giving your cannabis plants a good pruning and what you should look out for.

Pruning or Topping?

Topping refers to the haphazard way of hacking down tree branches to shape a tree, most likely severely damaging it. Not great! However, like cannabis plants, pruning trees refers to carefully cutting away dead or dying leaves and strategically removing branches to allow the tree to maximize light penetration, optimize growth, and flourish.

Topping is another term used in the cannabis world that you might hear. Topping a cannabis plant means cutting the main stem in order to train the plant to direct energies into growing stronger side branches. This technique is also commonly done on many tree species.

Note that pruning is a high stress training technique that comes with its fair share of risks. For example, if done wrongly, the cannabis plant can do into shock and have difficulty bouncing back. However, cannabis is a pretty hardy plant that’s incredibly forgiving, so don’t be afraid to give it a shot, after all, practice makes perfect!

Why Prune Cannabis Plants

Pruning your cannabis plants often leads to happier, healthier plants that ultimately will yield greater amounts of those high potency buds we all know and love. Here are the most common reasons why good growers take great care in pruning their plants.

Improve Airflow and Prevent Diseases

By removing lower, dying, and wilting leaves, there will be more space on the interior of the plant and better airflow. In plant care, good airflow means you can reduce the risk of mold or fungal issues. If you don’t prune your plants, you’ll risk making the humidity too high which could lead to numerous problems.

Light Penetration

Another benefit of removing unnecessary leaves is better light penetration throughout the plant. This will give the remaining middle and lower leaves a better chance to absorb light and convert it into energy through photosynthesis.

Efficient Use of Resources

Leaves that are wilted and dying don’t need any more nutrients, and the plant would be better off channeling that into its healthy parts. In addition, lower branches and buds that have very little chance of getting the appropriate amount of light can also be taken off since they too, are taking away the plant’s energy that could be better used elsewhere.

When to Prune Cannabis Plants

Now we’ve covered the why, let’s look at the when. The best times to prune your cannabis plants are during their vegetative stage and early flowering stage.

Vegetative Stage

The vegetative stage in a cannabis plant's life is right after the seedling stage and before the flowering stage. This crucial stage is when the plant shoots for the sky and focuses its energy on growing a strong main stem and root system as well as healthy leaves and branches.

At this point, you can consider topping the plant to break apical dominance, which means the main stem could be stunting the growth of other branches.

During this stage, you’re likely to notice a dramatic increase in biomass. Depending on your strain, the vegetative stage could last from 4 to 8 weeks. Ideally, you should start pruning when it grows a sturdy stem and several sets of leaves.

Early Flowering Stage

In the early flowering stage, a female plant will have pistils emerging out of her nodes. You can remove the leaves that are blocking airflow or restricting light, especially if they are casting shadows on bud sites.

You can also look at removing the lower branches and leaves that are not likely to receive enough light to grow significant buds in a technique called lollipopping. This forces the plant to direct energy to the top buds which get the most light exposure, resulting in bigger, denser buds.

Be careful at this stage though. If you over prune, you might stunt its growth and the plant will have too few leaves to generate enough energy.

How to Prune Cannabis Plants

Now you know the why and when to do so, let’s take a look at HOW to prune your cannabis plants. First, prepare a few crucial tools that you’ll need. Here’s a checklist.

Step-by-Step Guide to Pruning Cannabis Plants

Step 1

Prepare your tools and the plant. Anything that touches the plant should be sterilized first to avoid spreading disease. Also slowly start decreasing your plant’s nutrients about a week or so before and after pruning to reduce the risk of shock.

Step 2

Identify the nodes and decide where to cut. During the vegetative stage, aim for branches that have little chance of getting enough light penetration as they grow, and this usually means the lower ones.

You should also look at the plant as a whole. If one particular branch is too high up and blocking the light from reaching the others, you can consider removing it before it affects the others.

Step 3

Make a clean cut using your sterilized shears above the node.

Step 4

To care for the plant after pruning, water it and wait another week before fertilizing so it can adjust to the new state. Consider adding a vitamin B complex fertilizer that you can give along with the water to help strengthen roots.

Final Thoughts on Pruning Cannabis Plants

Pruning cannabis plants is one of the numerous topics that the cannabis community is divided on. Some swear by it and some refuse to do it, but the facts are undeniable, and that is when a plant is properly pruned, it can flourish and reward you with the most glorious, healthy buds when it's time to harvest.

Check out AussieHempSeeds for other growing tips and browse some of our latest strains. We hope you enjoy growing them as much as we do!