How To Increase Cannabis Yields With Root Pruning (Updated 2021)

 For many growers, the topic of pruning cannabis can be controversial at best. Is it worth it to prune marijuana plants?

It can increase yield, so I absolutely say yes, but there are risks involved when pruning cannabis.

The thing is, pruning has many benefits, but it’s not the only way to increase yield. There are other plant training methods that you can try. The trick is finding the right one for your comfort level and doing it correctly.

What Is Cannabis Root Pruning?

With root pruning, you prevent your plants from becoming root bound, boosting their health and production potential as a result. Root pruning is especially important if you’re growing mother plants, as these will become root-bound sooner or later. But root pruning is also beneficial for cannabis that you grow for just one season.

The reason for this is that container-grown cannabis is limited by the volume of its pot. As such, when your plant becomes “root bound”, the normal next step would be to repot into a larger container.

But repotting isn’t always optimal or possible. It stresses plants, and not everyone has the space to constantly “upsize” into bigger containers. For large mother plants, constant up-potting may not be a solution either. At some point, you may need a gigantic container. This isn’t just impractical; with root pruning, it’s also unnecessary.

There are two ways by which you can go about root pruning: One is manual pruning of the roots, and the other is air pruning. Let’s look at the differences between the two.

Air Pruning vs Manual Pruning

As opposed to manual root pruning, where you take a knife directly to your plant’s roots, air pruning happens automatically. Once roots come into contact with fresh air, which happens when they reach the edge of a permeable container, the roots are naturally pruned and grow a double tip.

The new tips will then make their way through the medium again until they again reach the edge of the pot. Compared to plants grown in ordinary (closed) pots, the roots will continuously grow sideways and prune themselves many times. As a result, the root mass will increase significantly, up to 5x more than in an ordinary planter.

Increase your yield with pruning techniques

Want to know one of the easiest ways to increase your yield?

It’s pruning.

Gardeners of every type prune their plants to keep them trim and tidy. For many of them, it’s simply because the plants can grow out of hand and become too difficult to deal with any other way.

Plus, it has little risk since pruning is relatively harmless to the rest of the plant.

But there are more benefits to pruning:

For some plants, such as marijuana and tomatoes, pruning can also cause higher yields.

What cannabis grower wouldn’t want tidy plants with higher yields?

Pruning cannabis plants helps keep plants small while also optimizing it so that the bud sites receive the best light and airflow.

This is especially useful for places where the laws limit the number of plants you can have. Pruning helps a grower have fewer plants while enjoying the same yields as before.

If you do it right, your valuable marijuana plants can become even more valuable.

Pruning is one step beyond the basics of giving plants life and keeping them happy and healthy. It’s not, however, for beginners.

Here’s why:

You need to give the process some thought and planning beforehand. The process of pruning marijuana plants is delicate, and you could damage your plants. If you don’t fully know what you’re doing, don’t prune at all.

Keep in mind, you don’t have to prune.

Some experienced growers never prune their plants. They prefer to let nature do its thing. This is not that bad of an idea since pruning has its risks.

However, pruning in a controlled, moderate way can be extremely useful. When done correctly, you can produce the healthiest, best-growing plants with the most THC.

Cannabis Training Matters

Cannabis plants are usually clonally propagated and transplanted during various stages of development. Cannabis training involves guiding the plant’s form, through physical manipulation, to alter hormone levels in various plant parts. The translocation of hormones and other biochemicals results in a slowing of root development when biomass is removed from the phyllosphere and slowing of shoot production when root expansion is restricted.

Bending plants to change the apical orientation of shoots can result in significant changes to plant form without slowing development or stressing the plant. Due to the labor required to bend and secure branches, this technique is usually applied to small plants, where radical structural changes can result from simply bending a plant, and securing a selected fan leaf to its container with a clothespin.

Well-rooted plants can quickly recover from more intensive forms of training including topping and heavy pruning. Topping a plant involves removing the shoot apex. This intervention results in accelerated lateral branching and suppressed root development due to reduced auxin translocation to lower plant parts and the resultant shift in hormone ratios.

Supercropping refers to physical compression of vascular tissues in stems to limit auxin transport. This is usually achieved by squeezing a branch between a thumb and forefinger. The effect on lateral branching of nodes below the compression is similar to topping, but more transitory, with less inhibition of general plant development. If done carefully, no wound is created for potential pathogen ingress. This technique can be difficult to standardize and implement at scale, as the amount of pressure required to compress vascular tissues without rupturing the epidermis is variable, and the effect is temporary.

Root training requires no additional labor and results in significant benefits for plant productivity. Nutrient uptake is highly related to surface area of the rhizosphere. Container selection, substrate structure, and irrigation methods contribute to development of a fibrous root mass. Air pruning pots guide root apexes to holes where they desiccate, stimulating lateral root branching and eliminating root circling issues.

Why Root Pruning Is Essential for Mother Plants

Cannabis is an annual plant, which means nature didn’t intend for you to keep a single plant around for a very long time. If we want to keep a mother plant in the growing phase, this means we need to cheat a little in order to keep her healthy and give us quality cuttings. We can do this “cheating” by pruning the roots, which is indeed essential for mother plants.

When grown in an ordinary container, plants will soon reach a limit determined by the volume of the planter and substrate available. In addition to the roots “choking” themselves at some point, when plants have been growing for too long in the same container, the substrate becomes compacted, with layers of minerals forming on the surface. The poor structure of the substrate makes it difficult for water to penetrate, which leads to dry pockets in the soil and makes uptaking water more difficult. The health of your mother plant will slowly suffer, and so will the quality of your cuttings.

Root pruning can prevent this from happening. Any time you root-prune a mother plant, you’re renewing the plant’s root system, plus you’re also adding fresh substrate. Your mother plant will be happy at all times!

What’s more, some cannabis strains, like certain Hazes, are particularly sensitive to the stress of becoming root-bound. This can even cause plants to start flowering. Not exactly what you want for your precious mother.

Conclusion

So, the takeaway? Just grow! Grow, and don’t be too worried about failure. Cultivating cannabis is a massive learning curve. Obviously, we all want massive yields of the most potent bud around, but you’re likely to be disappointed if you set your expectations too high. For novice growers, getting any kind of crop is an achievement.