Defoliation is the definition of controversial in weed cultivation circles. Some growers swear by it, others not so much.
But when you are trying to maximize your crop yield, selectively and carefully removing some of the fan leaves (especially ones shading bud sites) can help.
Some cultivars grow super bushy, to the point where airflow and light penetration are restricted, and humidity levels rise. That's when defoliation may be the help you're looking for.
- What does it mean to defoliate cannabis?
- Advantages of cannabis defoliation
- Risks of cannabis defoliation
- How to defoliate cannabis plants - step by step guide
- Can you defoliate autoflowering plants?
- Can you defoliate and top cannabis?
- How many leaves should you remove?
- What happens if you defoliate too much?
- Can you remove all of the fan leaves during the flowering stage?
What does it mean to defoliate cannabis?
There are a couple of different weed defoliation techniques, but at its core, defoliation is the process of removing some of the fan leaves, usually to help increase light exposure and airflow for the plant.
It can be as simple as snipping off a couple of the bigger fan leaves or as heavy as Schwazzing (where you remove almost all of the fan leaves).
Advantages of cannabis defoliation
We have mentioned the two big advantages of defoliation, which are improved light exposure and airflow to the budding sites. But there are a couple of other advantages that this technique can offer:
- Increases in yields: By removing some of the fan leaves, you are allowing more light to reach the plant's lower and inner bud sites. This can lead to bigger and denser buds, resulting in higher yields.
- Reduction of pests and disease: Dense foliage is an enticing home for pests, and high humidity levels can lead to mold and mildew growth. By defoliating, you reduce the chances of pests making your favorite plants their new home.
- Better energy distribution: Removing some fan leaves can help redistribute nutrients to other parts of the plant that need it more, leading to overall healthier growth and development.
Risks of cannabis defoliation
Now, it's not all sunshine and rainbows when it comes to defoliation. There are some risks that you should be aware of before taking the snippers to your plants:
- Over-defoliation: Removing too many leaves can stress out the plant, leading to stunted growth and potentially lower yields. Some growers may find great results from heavy defoliation, but it's not a one-size-fits-all technique.
- Infection entry points: When you make any cut on a plant, bacteria or fungi can enter and cause an infection. This risk can be minimized by using sterile tools and making clean cuts close to the stem.
- Timing: Defoliation should be done carefully and at the right time in a plant's growth cycle. You could harm your plant's development and yield potential if the timing is wrong.
How to defoliate cannabis plants - step by step guide
![man defoliating cannabis leaves with scissors](https://www.420-seeds.com/wordpress/wp-content/uploads/webp_image/sites/2/2024/07/man-defoliating-cannabis-leaves-with-scissors.webp)
Before we dive into the steps, let's talk about when you shouldn't defoliate a weed plant.
Removing healthy foliage can stress your plants, so you should only defoliate plants that are super healthy. Look to only defoliate plants that have strong, upright stems, green leaves, rapid growth, and a well-draining, fast-drying medium.
Avoid defoliating any plants that are frail or are potentially being hit by nutrient deficiencies, improper watering, nutrient or light burn, wind damage, or pest/disease issues. Defoliating stressed plants will make things worse, so only carry out this technique on healthy plants.
You may also see advice stating, "only defoliate indoor plants". We don't subscribe to this theory and think outdoor plants can also benefit from defoliation. Just be conscious of the strain you are growing, timing, weather conditions (hothouses and high humidity are an exception), and the overall health of your plants. And if you have had any issues with pests, it's probably best to just let your outdoor girls do their thing.
Right, with that out of the way, here are the steps to successfully defoliate your cannabis plants: The larger fan leaves can be removed next. They block more light and airflow
- Go for any yellowing or damaged leaves first: Yellowing leaves are a sign that they have stopped producing energy, so they should be removed first. These leaves won't help in photosynthesis and will eventually fall off anyway.
- Remove the larger fan leaves: The larger fan leaves can be removed next. They block more light and airflow, and removing them will help the smaller leaves below get more access to both.
- Trim any shaded bud sites: If you have dense foliage on your plant, you may have some bud sites that aren't getting enough light. Trim away the leaves above them to give these buds more direct light exposure.
- Treat them like the queens they are post-defoliation: Once you have made you cuts, make sure to give your plants some TLC. This includes watering, providing adequate nutrients, and adjusting lighting and temperature if necessary.
But we haven't mentioned timing properly yet...
During the vegetative stage
There's a lot of info out there regarding when the best time to defoliate a cannabis plant is. Some people say defoliating during the vegetative stage will delay flowering, but others say it won't affect it at all.
Our advice?
If you are growing indoors, we recommend doing one decent defoliation during the vegetative stage (around 15 days before the flowering stage begins). This will give your plants plenty of time to recover and grow before switching to flowering.
Outdoor growers can be a little more liberal, and just carefully remove any damaged or yellowing leaves whenever they like during the vegetative stage.
During the flowering stage
Things get a little trickier during the flowering stage. Removing too many leaves can definitely shock the plant, resulting in smaller yields or slow growth.
Our advice?
Indoor growers should target the third week of flower production as the best time to defoliate. This gives your plants enough time to recover and produce healthy buds for the remaining weeks of flowering. It's also important not to remove too many leaves at once, so try to spread out your defoliations over a few days this week.
Outdoor growers can just remove leaves that are blocking the sun as they see fit, just don't overdo it.
Can you defoliate autoflowering plants?
Yes, but just keep in mind that when defoliating autos they don't have as much time to recover as photoperiod plants do. Be gentle and conservative with your defoliation techniques, and only remove leaves that are causing problems.
Can you defoliate and top cannabis?
Yes, you can defoliate cannabis and top it. You should be topping cannabis much earlier than you would defoliate it, therefore they should not affect each other. However, you should still play by the same rule, that if your plant shows any signs of stress then avoid defoliation until it has recovered. You should be able to top then LST train and then also use defoliation on the same plant in that order.
How many leaves should you remove?
We like to keep it around the 30% mark (of fan leaves).
What happens if you defoliate too much?
Over-defoliation may not harm your plants at all. Some growers see great results with super-heavy foliage removal. But keep in mind that fan leaves act as nutrient storage for your plant, so removing too many could result in nutrient deficiencies and slower growth.
Can you remove all of the fan leaves during the flowering stage?
You can, but we don't recommend it. We just haven't seen the type of results that match the effort put in. But, if you are feeling a little intrepid and have an extra plant to experiment with, give it a go and let us know how it works out for you!