Previously, we discussed the importance of pruning your cannabis plants. In that article, we explained that the primary objectives in defoliating your plants is to create the ideal shape, as well as remove fan leaves that may constrict air flow or light penetration.
In this article, we will help you understand at what phase of your plant’s growth cycle should you take the scissors to it and start removing fan leaves and other foliage.
A Review of the Reasons for Defoliating Cannabis
Before we explain when you should defoliate your plants, it is a good idea recap why we are defoliating our plants. This will help you understand the ideal times for removing fan leaves and cutting on the plant.
When we grow weed, our goal is to grow the best weed, and get as much as possible. We want to get as much bud per plant as possible, but we also want that bud to be the best quality. We want dense buds, not squishy or larfy buds, signaling lack of development. Bud density is very important.
The biggest contributor to density of the buds is getting enough photons of light to the plant. Buds that are shrouded in bushy foliage will not get the same development as buds that are bathed in the sunshine of PPFD. Nor will the overall yield be as high.
Therefore, our goal is to create a plant canopy that allows as much of the plant to bath in the rays of our lights as possible. We do this by weaving our plant through trellis, and making sure that needless fan leaves and branches are not obstructing the major flower sites.
Which requires proper pruning and defoliation.
You should prune your cannabis plant during the Vegetative Stage
Pruning during the vegetative stage is a great way to get ahead of any problems and start the process of training your plant for maximal yield and quality during the flowering stage.
During the vegetative stage, your plant is immature and therefore malleable. Because of its lack of maturity, plants of this age are capable of being trained and shaped. And one way of doing harnessing this control over your plant is to strategically prune it during the vegetative phase.
Start pruning your plant after your plant has a good root base and is over a foot tall. Start by removing everything at the bottom and working your way up. Within the first six to eight inches of the plant, cut off branches and nodes with abandon. Go even higher if you want.
Get everything up and off the dirt. We want vertical growth. Later in this plant’s life we will want to encourage going wide. But early in veg, like right after rooting a clone and getting a foot tall, we want continued vertical growth. So nip off that stuff at the bottom and encourage this plant to start growing tall.
We actually filmed a session of pruning our plants five weeks after cloning. In that video, you will get a good idea of how to prune your plants during veg.
How many times should you prune during the vegetative stage?
We usually prune our plants twice during the vegetative stage. First, we prune them early in veg, prior to topping, as discussed above. We then wait a week before topping our plants. Later, we will prune and defoliate one more time before flipping into flower.
At this late stage veg, we will really aim for the lollipop shape, which is the same shape we want during the flowering stage.
If you found that article helpful, you might want to check out the entire series Week-by-Week in Veg.
Defoliate your cannabis Plant during the Flowering Stage
Once your plants are in the flowering stage, you will definitely need to defoliate them during or after the post-veg stretch. That is because after switching to the 12/12 light cycle, your plant will go through a tremendous growth spurt for about three weeks.
We recommend defoliating your plant in Wee 2 of Flower. This is usually a good time to go in and get ahead of the mess. You could wait until Week 3 or Week 4. You could also go in and do some pruning in Week 2, with a follow up in Week 4.
It is really up to you and dependent on your cultivation style. You can defoliate multiple times during the flowering stage, or just one heavy defoliation early or in the middle.
We do not recommend defoliating in late stage flower. At that time, you want your plant focusing its energy on bud development, and you don’t want the plant dealing with the stress (and subsequent recovery delay) of defoliation.
This is why we recommend defoliating during the vegetative phase. Get your plant pruned up and looking clean cut going into the flowering stage. This will better prepare you for the stretch phase, and ease up on the amount of work you’ll have to do.
It’s always better to stay ahead than to fall behind.
Another good idea is to remove all fan leaves just prior to hanging your plant up to dry.
Yank off only the large fan leaves, that will not be used for anything — not for processing or for any real use. Get rid of them. They will only put more chlorophyll in the air that will have to be removed.
Additionally, if you want your trim to have any value — to you or anyone else — you will want it to consist mainly of sugar leaf and other plant material that has trichomes or kief. Fan leaves contribute nothing to you biomass other than mass, which simply dilutes the quality and potency.
Having fan leaves in your trim will result in lower yields of your concentrate.
Other Resources on Harvesting, Drying, and Curing
For those looking for a comprehensive guide, we actually wrote a 6,000 word article (about a 20 minute read) that explains everything involved in harvesting, from drying, curing, and hand-trimming.