How to Prune Marijuana Plants and Boost Growth

Pruning Plants and Increasing Yields
November 25, 2020

Every cannabis grower wants to boost plant growth and productivity. The question is, how do you go about it? There are several methods to choose from, but one of the simplest and most effective is to prune the plants. Really, all you need is a sharp blade to get started.

But, you can’t just start hacking away at the plants. Like any other growing technique, pruning also poses some risks. Make sure you are aware of them so you could carry out the procedure with the least possible damage. If successful, not only do you grow larger, healthier plants but also increase the yields by up to 25%. As if that is not enough, the resulting buds will also be denser and more potent.

Sounds good? Let’s get right to it. In this article, we’ll tell you all you need to know about pruning marijuana plants, including:

  • What is pruning?
  • What are the benefits of pruning?
  • When do you do it?
  • What do you look for when pruning?
  • What are the things to keep in mind before pruning?
  • How do you prune marijuana plants, and what do you do after?

Pruning Marijuana Plants: What You Need to Know

Pruning involves removing certain parts of the plant. Gardeners often do it to keep the plants neat and trim, making them easier to manage. It is similar to grooming, so to speak. But for marijuana growers, it is also a way of boosting growth while increasing the quality and quantity of the yields.

When pruning, the goal is to snip off useless plant constituents – most notably dead leaves and auxiliary branches. These only force plants to use valuable resources.

It is not unusual for the lower leaves to start yellowing and withering at one point in the growing cycle. That is because the upper growth is obstructing their light access. The limited light intake also means that they would never grow the desired large, trichome-rich buds. Unfortunately, the affected foliage takes time to fully die out. And it will continue to sap the resources as long as it remains hanging on the plant. Talk about wasted energy.

As for the auxiliary branches, they are small and could only produce popcorn buds at best. Why settle for tiny florets when you could grow bigger ones?

If you remove these freeloaders, the plant can redirect the energy to more critical parts – such as the healthy leaves and main stalks. Ultimately, the efficient use of resources and light energy leads to improved overall growth and productivity.

When to Prune

When pruning, timing is critical. Typically, it is done during the second week of vegetative growth. By this point, the plant would have developed several internodes already. This will give you a rough idea of its growth patterns, including where the quality buds will sprout from. More importantly, it would be mature enough and can continue growing new nodes and leaves.

Note: Nodes – also called the growth tips – refer to the intersection between the branches and the central stalk. It is also the area where the buds pop up. Internodes, on the other hand, are the gaps between the nodes. If you are growing an Indica, you might have to wait for another week before pruning. That is because they tend to grow more slowly than Sativas.

Marijuana plants usually keep growing until three weeks into the flowering stage. You can prune up to two weeks after flipping the switch, which gives the plants enough time to recover. Never go beyond that, though. Otherwise, the plants end up spending too much energy on healing instead of budding, lowering the quality and size of the harvest.

What to Look for When Pruning

Remember, pruning is mostly about removing unnecessary plant parts. To do that, you need to zero in on areas not getting ample light. With that in mind, here’s what to look for when inspecting the plants.

  • Nodes or bud sites that are too low down to receive enough light.
  • Leaves that are dying off – as indicated by the yellowing and wilting – due to insufficient light.
  • Lower branches with poor light access due to the topmost growth.

At first, it may take some time before you find the areas that need pruning. Don’t be discouraged, though. With experience, it will eventually feel like second nature.

What to Keep in Mind Before Pruning

Being prepared and well-researched plays a massive part in the success of any endeavor – pruning included. If you know precisely what to do, there is less risk of harming the plants and stunting their growth. Listed below are some of the most important considerations.

Not Compatible with Autoflowers

Let’s get this out of the way. You should not prune autos. Due to their short growing cycle, autoflowers will not have enough time to bounce back to health after being shaved off. To be safe, stick to photoperiod plants.

May Not be for Beginner Growers

Pruning is a pretty straightforward technique. Still, there is a bit of a learning curve needed. Not to mention, you could cause irreversible damage to the plants – including reducing the yields – if you do not know what you are doing. So, if you are a novice grower, this may not be time to experiment. Ideally, you should already know the basics of cannabis cultivating before trying it out. But if you really want to, just prune a single plant – not all.

Cut Cleanly and Carefully

While a relatively safe procedure, pruning is not risk-free. If you are not cautious, you could damage or shock the young plants and introduce harmful diseases.

Needless to say, you should not use your bare hands to tear off the branches. Avoid dull and serrated blades as well. Instead, go for a sharp, sterilized cutting tool, such as a pair of scissors to make clean, precise snips. You could never go wrong with these pruning shears from Fiskars.

To prevent the plants from being infected, make sure to sanitize the blade between cuts. All you need to do is dip the tool into isopropyl or rubbing alcohol.

Trim off the Lower Branches Early

Growing productive marijuana plants entails maximizing the available resources. In that regard, make sure to remove the lower, unnecessary branches as early as possible. These will never produce fully-developed buds due to having limited light access.

Always Remove the Dying Parts

We cannot stress enough how wasteful it is to keep dead or dying leaves on the plant. Again, they will only rob the healthier upper leaves of precious resources. Make sure to shear them off as soon as they start turning yellow.

Remember, the affected leaves are typically at the bottom and shaded by the plant canopy. If the yellowing and wilting emerge in other areas, you might be dealing with a nutrient deficiency.

Don’t Prune Budding Plants

This has already been mentioned before, but it is incredibly urgent and deserves a reiteration. Never prune marijuana plants once they start flowering. The most you could do is remove a few dead leaves or unproductive branches. But full-scale pruning? Don’t even think about it.

Any extensive snipping will most likely just shock the plants. As you may know, stressing out cannabis plants during the blooming period could compromise the yields. You don’t want to risk it.

How to Prune

There are various ways to prune marijuana plants. Trimming the lower branches is the most straightforward – it is also the most important.

After removing the unproductive growth, you can proceed with more advanced techniques such as topping, fimming, and lollipopping. Each has distinct pros and cons. It is up to you to choose which one best suits your needs and preferences. Many growers opt to use more than one technique.

Regardless of the method, the goal is the same – better growth and higher yields.

Option 1: Trimming Lower Branches

This is the traditional way of pruning marijuana plants. Again, it is all about removing the lower, unproductive growth. Of the four methods, it is the simplest, making it suitable for beginners.

How to do it:

1. Ready the cutting tools. Make sure it is already disinfected.

2. Examine the marijuana plant. Note the sections you need to trim off, including low-down branches and dying leaves.

3. Remove the larger branches first, starting with the ones near the plant base. This can help clear out space, making it easier to find the sections that need more pruning.

4. Snip off the branches in the middle of the plant, directly beneath the canopy.

5. Now, you can focus on more detailed work. Find any small or dying branches and leaves. Trim them off neatly.

Option 2: Topping

As the name suggests, topping involves removing the top part of the plant. Doing so will halt the vertical growth, inducing the remaining branches to grow horizontally. It will help stimulate the growth of new shoots as well.

This setup has a couple of notable benefits. Not only does it help the plant maximize light access, but it also allows you to grow multiple colas instead of a single central cola towering over the rest. More light and more colas basically mean more buds to harvest later on.

Keep in mind that topping may slow down growth to an extent. This rings especially true for strains that naturally take a while to mature. For this reason, you should top as early as possible to give the plants more time to grow while reducing trauma. Ideally, the plant should be about 10 inches tall and already has 5-6 nodes.

How to do it:

1. Select the topmost shoot. Hold it down.

2. Carefully snip it off right on top of the node. Remember, keep the cut clean and exact.

3. After about three days, you will see two new stalks with leaves on them growing on either side of the removed shoot. This pair will eventually grow to become the main colas.

Option 3: Fimming

Fimming is a variation of the topping technique. The primary difference between the two is where you cut the plant. Instead of trimming off the topmost shoot entirely, you only remove it partially. This creates four new stalks – sometimes even more – instead of the usual two. More leaves mean higher light intake, translating to increased growth and yields.

This method does have a few downsides, though. Compared to topping, it could cause more considerable damage to the plants, which means that they would need more time to recover. This results in slower growth.

Outdoor growers also need to be careful when fimming tall, heavy plants – such as Sativa strains. They could buckle under their own weight and split into two. To avoid this, strengthen the plant by taping it under the fimmed area.

How to do it:

1. Ready the sharp, sterilized blade.

2. Take the newest growth. Hold onto it.

3. Cut off at the stem in between the nodes about two-thirds of the way. You’ll mainly be removing the leaves while retaining most of the stem.

4. Again, you should see two new shoots – each with their own leaves – developing in as early as three days. The middle of each stalk, in turn, will form new shoots in the next few days. Eventually, you would end up with four main buds.

Option 4: Lollipopping

Lollipopping involves removing the lower growth of the plants. Doing so sends the energy to the upper sites, resulting in better bud development. This is particularly useful in setups where the light cannot reach the bottom section anyway. If successful, expect bigger, higher-quality colas.

By removing the bottom leaves, you also create extra space, consequently improving air circulation.

There are two ways to lollipop marijuana plants. You can do it either as a continuous process during the vegetative phase. Alternatively, you can do it all at once, two weeks before the flowering stage.

Top-down lollipopping:

Many cannabis growers consider this technique as more extreme. But if you are extra careful when making the cut, there should not be any issues.

Start by deciding where the canopy will begin. Examine the plant to see which areas are being shaded by the upper growth. Some typically choose a point that is around four nodes down from the growth tips. To lollipop, simply remove all the growth – the small branches and the side stalks – below the chosen location. Remember to use clean, sharp scissors.

By the end, the plant should resemble a lollipop – a long, bare stem at the lower section and leafage on top.

Bottom-up lollipopping:

Of the two, this method is considered less damaging. As the name indicates, you start removing the growth from the bottom, slowly making your way upwards.

First, snip off the main lateral branches on the lower growth. Remove any small leaves as well. Keep at it until the bottom third of the plant has been cleared out, leaving only the stem behind.

Note that the bottom-up approach may require some maintenance trimming as the plant vegetates.

What to Do After Pruning

Water your marijuana plants immediately after pruning. Doing so minimizes stress while stimulating growth. Additionally, feed them with the appropriate dose of nutrients to facilitate a speedy recovery.

Make sure not to force them to flower right away. To be safe, keep the plants in the vegetative stage for a week. Make it two if you have the time. You want the plants to be strong and hearty before budding.

Now, all that is left to do is care for the plants during the flowering phase. Come harvest time, get ready to collect a generous yield of large, dense marijuana buds.