Fimming in Marijuana Cultivation

There are plenty of pruning techniques that are useful to increase plants’ productivity. Difficult methods require a certain degree of experience to prevent mistakes that are too serious for the plant to overcome. Lucky enough, fimming is one of the easiest and most productive techniques and at the reach of any grower, regardless of their level of experience.

What is fimming?

Fimming is a high stress technique that derives from Apical pruning. It was discovered by mistake in the 90’s, by an American cannabis grower who was trying to perform an apical prune to his plants. History says that when he realized about his mistake he said “ Fuck, I missed”, which is where the name FIM comes from.

FIM’s objective is to increase cannabis plants productivity by removing the apical bud partially, instead of removing the first node completely. This way, instead of obtaining two new branches, which is what would happen with an apical prune, you’ll get five new ones that will grow with the same strength as the cut off bit.

How to FIM plants, step by step

Fimming a cannabis plant is very easy and doesn’t require too much experience, as long as you follow each step carefully. This technique consists of removing just some of the apical bud, therefore, all you have to do is hold the tip of the plant firmly and cut approximately 70% of the apical bud.

By doing this you’ll get at least 5 new branches in a couple of days and they’ll grow with the same strength as the stem that was initially in that same spot. We recommend using special tools for this purpose or at least a very sharp knife or scissors, although if you damage the stem, the plant can have difficulties creating new branches. The best option to perform fimming is to use Round Tipped Scissors, sterilizing them beforehand to prevent infecting the plant with any pathogens.

When this technique first showed up, it was difficult to understand why cannabis plants behaved in such a way when the apical bud was partially cut with the fimming method. Nowadays we know a lot more about cannabis structure and composition, making it easier to understand the growth process of the new branches.

How do Cannabis plants react to fimming?

Marijuana plants have a lot of internodes per centimetre in the apical sprout. The apical sprout is a type of bud protected by small layers of leaves. All of those small leaves come out of a node, and the internodes stretch out as the plant grows.

Thanks to the node concentration, cutting the apical sprout on the exact necessary spot forces the creation of between 5 and 10 new branches. However, cutting on the exact spot to promote as many branches as possible is very hard and requires a lot of practice.

When to FIM cannabis plants

In order for plants to overcome the stress caused by fimming and recover successfully, it must have at least between 3 and 5 nodes. This will happen approximately one month after its germination; which is when the stems and roots are strong enough to recover from this process.

It’s important to mention that this method is only suitable during the growth phase. Fimming during the flowering period will ruin the yield and stress the plant beyond recovery. When plants suffer a stressful episode, they center all of their energy in sorting it out and healing themselves; leaving any other process, including growth or flowering, behind.

Advantages and disadvantages of fimming

Advantages

• Increased yield
• Sturdier plants as they have to boost their growth phase
• More branches
• Easy to do

Disadvantages

Although fimming cons are scarce, you should take them into account before applying this technique.

• If the technique isn’t done properly, the new branches will be too weak to withstand the weight of the buds; in such a way that even wind or rain could break them.
• Fimming incorrectly could form a callus where nothing would grow; although the two sprouts that develop with apical pruning would grow.

Differences between apical pruning and fimming

The main difference lies in the way the apical bud is cut. In apical prunes, the apical sprout is completely removed; whereas for fimming, you remove only part of it. Each cut obtains different results. The first one transfers the dominant sprout to the two lower ones, forcing the plant to form two apical buds. Fimming, on the other hand, promotes vigorous branches.

Both techniques are suitable for plants with delicate characteristics; whether that is the need to create short and discreet plants or because the cultivation area is rather small. This technique will increase the yield in those situations.

Fimming is effective in itself, but combined with other cultivation techniques, it can offer extraordinary results. The most compatible growth techniques for fimming are Screen of Green (ScrOG) or lollipopping. You can actually combine the three methods in the same grow; pruning the lower branches with ScrOG to promote proper airflow and encourage the plants to center their energy on the top buds (nearer to the light) during the flowering period.