Fimming cannabis: How to maximize your yield


‘Fu$k I missed’, or fimming is a trimming method that you can apply to cannabis plants during their vegetative stage to increase the number of bud sites. 

It’s done by cutting the upper half of the new growths on your plants which will cause them to produce multiple new branches.

Fimming is often confused with topping since both methods involve removing the tops of your cannabis plants

The difference between the two is where the cut occurs. 

Topping removes the entire top growth to produce new bud sites, while fimming only removes the upper half.

How does fimming work?

How to fim marijuana
How to fim marijuana

How do you ‘FIM’ cannabis plants?

When fimming marijuana plants, you need to consider a couple of things before you start trimming.

First, you need sterile tools and clean hands to avoid infection right off the bat. 

To cut, you need to choose the topmost growth of your plant and trim most of it (around 80%).

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Timing: when to FIM

Like most high-stress training methods, it’s best to apply fimming during your weed plant’s early vegetation phase, when they’re at least 3-4 weeks old. 

During this period, your plants prioritize growing larger and producing new growths in this stage, meaning they can handle the stress of pruning those new growths.

If you fim your plants right before they flower, it won’t produce new growths because your weed plants are more focused on growing their buds during their flowering stage.

Fimming marijuana plants in this stage will only cause damage and stress.

Fimming step by step

How fimming helps your grow

Fimming is a high-stress training method. Its main benefit is making your weed plants produce new bud sites, maximizing the yield you get from a single plant. 

Additionally, when you fim cannabis encourages lateral growth in your plants, which will grow outwards rather than upwards.

The process is similar to how you would mainline cannabis plants, wherein you would top the new growths and tie the branches down. 

The difference, though, is that with fimming, the branch structure that it produces is weaker. 

What that means is rather than tying the branches down, you’ll instead need to tie them to a trellis to ensure proper lateral growth.

Fimming isn’t your only option when it comes to increasing the yield of your plants.

There are other advanced growing techniques that you can use if you’re looking to increase your yield, like schwazzing.

Fimming: topping, but different

Fimming vs Topping

Fimming vs Topping

When choosing a trimming method to help increase the number of bud sites on your cannabis plants, you have two options, fimming vs topping. 

Despite their similarities, the two methods have pros and cons, such as the number of new stalks they produce and the branch structure of said stalks.

Fimming can produce more new branches from the cut you make than you would with topping

For comparison, fimmed plants average around 3-8 new bud sites, while topped plants can only produce two per cut. 

Additionally, it encourages lateral growth without tying your branches down.

However, the new stalks produced by fimming are weaker and often require a trellis to support them. 

For this reason, fimmed plants are often paired with scrogging, the same way that topping is paired with mainlining.

Topping vs fimming, which one is better? It depends. Fimming requires less precision than topping, and it produces more bud sites from a single cut. 

On the other hand, topping has more uniformed bud sites and a stronger branch structure than fimming. In the end, choose what’s best for you when deciding between topping and fimming.

Fimming step by step

fimming marijuana plant 1
Use 10 inch plant
fim marijuana plant 2
Select latest shoot
fimming marijuana plant 3
Use your fingers
fimming marijuana plant 4
Cut off 2/3
fimming marijuana plant 5
Just like this
fimming marijuana plant 6
Plant heals wound
fimming marijuana plant 7
 New shoots day 1
fim marijuana plant 8
New shoots day 3
fim marijuana plant 9
New shoots day 5

Step one

The first step to fimming weed plants is choosing the right one to trim. 

You’ll know when your plants are ready for fimming when there are 3-5 nodes on them, typically once the plant is 30 days into its vegetation phase.

Step two

Once you’ve selected your plants, you need to locate the topmost growth tip. 

After doing so, pinch it between your fingers while gently pulling away from the smaller leaves around the tip – this is so you can have a clear view of it before you trim it and avoid accidentally trimming leaves that your plants need.

Step three

The last part is simply cutting the tip. It’s important that you only remove around 80%. 

If you remove the entire topmost growth, you could end up topping your plants instead.


Fimming more than once

One of the more curious questions that growers often ask is ‘how many times can you fim a plant?’ 

Although possible, fimming a single plant multiple times by trimming its topmost growths is not recommended. 

Fimming, like all plant training methods that involve removing parts of the plant, is a type of high stress training (HST). 

HST has the potential risk of overstressing your plants, leading to slow growth, stunted growth, or causing them to hermie.

Additionally, a trait that fimming shares with topping (another type of HST) is that applying it to your cannabis plant increases the time it takes in its vegetative stage.

If you plan on fimming your plants multiple times, get cannabis strains with strong genetics. 

This will yield a better harvest, and by choosing seeds with good genetics, you ensure that the plants that grow from it can handle the stress of fimming and other plant training methods.

Topping vs Fimming
Topping vs Fimming

Topping vs Fimming – which is best for autoflowers?

Typically it’s not a good idea to apply any high-stress training on autoflowers, including fimming. 

With any HST, you need recovery time for your plants after you cut. 

With autoflower strains, it’s difficult to guarantee that time, considering how fast they grow.

Outside of timing, autoflowers don’t handle the stress of being pruned too well. 

Although they can handle harsh drops in temperatures, trimming is more shocking.

Pruning your autos could cause them to flower in response to the shock or, worse, hermie.

Topping also has the same problems that fimming has, but, just like with fimming, it’s possible. So, how does topping work with autos? 

You first need to choose a strain known for its height. Next, it’s a matter of knowing when to remove your plant’s topmost growth (apical bud).

If you don’t like topping or fimming your autoflowers, you can always try defoliating them. This is a safer alternative for autoflowering strains.

Fimming marijuana


Fimming is an excellent trimming method for beginner growers who want to increase their yield per plant using high-stress training. 

Hopefully, this guide helped you learn more about how to fim your plants properly; you can learn more marijuana growing tips in my free Marijuana Grow Bible

Remember, if you want the best results for your plants, you need to choose seeds with strong genetics. 

You can buy high-quality cannabis seeds with good genetics at my online seedbank,

Happy Growing


FAQs about fimming cannabis

When should you top cannabis plants?

You should top your plants during their early vegetation stage – or at least once the plant is 30 days into vegging. Your plants should be strong enough to handle the shock of having their apical buds removed.

How does fimming relate to scrogging?

It is often paired with scrogging because the branches that fimming produces are often too weak to hold the heavy buds that your plants will produce. The net you provide with scrogging helps to act as a way to support the branches.

The post Fimming cannabis: How to maximize your yield appeared first on I Love Growing Marijuana.

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