Pruning: The Debate

February 10, 2017   

Leafing, or defoliating as it is known in the growing community, is a very sensitive subject.  In many plants, trimming and pruning help to refocus energy from certain sections of a plant to promote the growth of other parts of the plant, usually around the flowering or fruiting phase of the plant cycle. There exist many innovative methods created through personal experiments by underground growers over the years. Among the various growing and training techniques, what is certain is that there is no major consensus on how and when to prune.

The answer to the question of when and if one should prune the fan leaves, varies grower to grower. There seem to be two camps of thought. Fan leaves are like solar panels that facilitate photosynthesis.  While removing vegetation allows redirection of nutrients and plant food, there is a debate amongst growers as to whether removing large fan leaves unsparingly may hinder the bud growth and quality of the end product. Experimenting with your crop can be a good decision, but pruning largely comes down to timing. One reason people might freely trim fan leaves at what seems like a premature moment, is that they are growing indoors, under stationary lights and must consider shade from fan leaves that block light from smaller leaves and other parts of the plant.

Other growers will point out that older leaves act similarly to a root system, in that they release stored nutrients and sugars to various parts of the plant in need of nutrition. So, if your fan leaf is beginning to yellow it might contain a significant amount of energy it has yet to distribute to the rest of the plant. The plant will shed its unnecessary or dead leaves naturally. If your root system is not strong, pruning these powerhouse leaves could actually harm your plant instead of promoting its growth. Using methods like Low Stress Training, which is when you bend your plants to gain more surface area, light coverage can help a grower avoid the impulse to prune too many fan leaves. Nevertheless, many growers will swear by defoliation as one of their most successful techniques for creating superior buds. Every farmer or grower should discover what methods and techniques work best for them by experimenting with their unique operation and environment.

Tuck, Don’t Pluck!                                                                   

Many growers who choose not to defoliate or prune their fan leaves recommend tucking leaves under branches to maintain the powerhouse leaves, while still allowing  for direct light to reach the rest of the plant’s nodes. These growers argue that the fan leaves are still photosynthesizing, building sugars that turn into THC, storing nutrients and exchanging gases important to the growth and quality of the buds.

If You Are a Plucker:

Avoid plucking outer and upper leaves that are getting the most sunlight and are therefore the most productive and essential leaves.

Some growers recommend minimally pruning in the flowering stage to expose the buds to light, which they claim makes for bigger buds. Taking too many leaves in the flowering state is argued to seriously harm a plant’s yield. Many growers advise against defoliating more than 20 percent per session, over a couple of weeks sparing a week in between leafing. More than this is believed to stunt growth. Pruning combined with certain training methods could be a great experiment for indoor growers.

Many experienced growers agree that when growing outdoors, pruning fan leaves does not matter or is less essential because of the space, aeration and natural damage to the plant from the elements and pests. Pruning fan leaves or thinning out a leafy plant when growing indoors, certainly promotes a healthier environment for your plants by eliminating extra growth that might attract mold or disease.

Experimenting has long been carried out underground. While scientific research on cannabis is continuous, the stories of growers before can guide new or struggling growers in their own experiments. The taboo nature of cannabis’ history pushed growers indoors, essentially encouraging growers to adapt and development some truly creative growing and training techniques. Stay tuned for an upcoming blog about different high stress and low stress training methods.


Contributed by Amanda Williams