Fimming is another HST technique used to increase yield that is similar to topping, but not quite the same.
The objective is still to increase the number of main colas. But instead of doubling down, fimming can give rise to 4+ new top colas. This technique is highly recommended for micro-growers with perhaps just 1-2 plants.
Secondary shoots are juiced with the growth hormone that previously would have been used to develop the main stem. However, most growers report that fimming is slightly less effective at reducing stretching than topping. A fimmed cannabis plant can still grow rather tall, albeit with far more top colas.
WHEN TO FIM CANNABIS
Wait until your plant has developed
3–5 nodes before you FIM it. Like with topping, performing the procedure too early will shock the plant and slow down the growth of your seedling. You should only FIM plants during the vegetative phase to allow plants to focus all of their energy on bud production during the flowering stage. If you want to train your plant during this time, try gentle techniques such as
low-stress training (LST).
HOW TO FIM MARIJUANA
Fimming involves pinching or cutting off around 75% of the tip of a plant. The very word FIM stands for “f*ck I missed”, and hints at how sloppy the technique appears. It looks as though the grower messed up their topping attempt! Looks aside, it’s an extremely simple and effective technique.
Grab the tip of your plant and gently elongate the growth with one hand. Use a pair of clean scissors to snip about 75% of the top. You'll be left with a small turf of growth that will eventually give life to four colas.
I am flushing a couple of plants right now. I will take a picture of one of them shortly and show the results of fim topping vs a main stem. No topping at all.
This gives a good yield and I can control the height of plants in my tent.