Training Methods: Fimming and Topping Marijuana Plants
Before we get into the topic for this weekend, take stroll with me down memory lane to our Bounty Blog entry on Mainlinning and our description of the cannabis plant’s natural structure and terminal dominance:
Picture a pine tree (a perfect example of apical dominance): like medical marijuana cannabis plants, pine trees demonstrate an obvious dominance in the apical/terminal tip–the pointed end where the star tree topper sits on a Christmas tree. At this tip or terminal bud is where the highest levels of a particular auxin (a plant hormone termed indole-3-acetic-acid (IAA)) can be found. In plant physiology apical dominance refers to the control exerted by this terminal bud (or main cola) over the growth of lateral buds. So basically the terminal bud stunts any lateral outgrowth from other bud sites.
While this unaltered model only has one main cola, using training methods such as mainlining, or today’s topic Topping and FIMming, creates a structure where apical dominance is eliminated, allowing for re-routed plant hormones to form more than just one main cola with the goal of generating greater yields.
Telltale signs that a marijuana plant has been topped or fimmed: look for several “main” colas almost always uniform in height.
Now that we have an understanding of why we would want to use the topping and fimming methods, let’s explore the what, when, where, and how to’s.
Topping Marijuana Plants
Topping marijuana plants means completely chopping off the newest node of a cannabis plant at the main stem directly above the leaves of the preceding node. This eliminates apical dominance & redistributes hormones creating 2 main colas instead of 1. You can continue to top the new main colas when they form to multiply the amount of main colas you end up harvesting. You can go from 2 to 4 to 16 colas easily.
Fimming is an acronym standing for “Fuck I Missed.” Fimming marijuana plants is just like topping except instead of taking off the new node in its entirety you only pinch off about 80% of it, leaving 20% of the node behind.
While this technique also eliminates apical dominance, fimming forms 4 main colas instead of the initial 1 or the 2 you get from topping.
The Time for Topping Marijuana Plants
Both techniques should only be performed during the plant’s veg cycle (18:6) and not during flower photoperiods (12:12). The reason being that the plant undergoes trauma and stress to a degree-I mean you are physically altering her structure by chopping part of her off, and it makes most sense for the plant to heal during veg instead of when flowering since most of her energy should be going into bud-site and flower formation.
Another point to consider is the purpose of the techniques; topping and fimming are tools that are meant to be used early on to facilitate structure manipulation and preparation PRIOR to entering the flowering stage, at which point it is too late.
The Place for Topping Marijuana Plants
Topping your marijuana plant should take place when it’s about 5 nodes tall, again during early stages of veg cycle. The same recommendation applies for fimming as well.
Fimming and Topping Marijuana Plants: Basic How-to Guide
For topping marijuana plants, gently take the top node between your index and thumb and firmly press for leverage. With clean scissors cut away at the main stem directly above the 2nd node from the top. Congratulations! You just turned 1 main cola into 2. These two new colas will form the leading part of a “Y” formed with the main stem.
Just like in topping, when you are fimming your marijuana plants take the top node between your fingers, but instead of cutting at the stem below the leading node “chew” off about 80% of it, leaving behind 20% of the node. The top of your plant should look like it’s been recently mowed or “chewed” off.
Fimming and Topping Marijuana Plants: The MissMMJ Geek How-to Guide
Fimming is actually less traumatic on your plants than topping and has less lag in recovery time. Plus, what’s the worst that could happen if you FIM incorrectly? Not too much harm done besides stupidly odd looking leaves where you mowed her.
If you’re looking to increase yield or just want to keep your girls short, then you should definitely consider incorporating topping and/or fimming into your gardening style. These techniques allow you to alter marijuana’s natural 1 leading main cola structure to that of a bushier, more uniformed multi-main-cola plant.
Once again I hope this helped, have fun being a magician amongst your garden turning 1 main cola into 2, 4, 16, etc., main colas! Happy growing!