Marijuana Pruning: Topping Vs Fimming

Contents:

WHAT IS TOPPING CANNABIS?

Topping is the process of pruning the growing tip of the main stem of a cannabis plant. This is perhaps the most common HST or high stress training technique applied by both indoor and outdoor growers. Marijuana growing naturally will typically take on a Christmas tree structure; One dominant, main central cola and multiple sets of side branches. All plant parts receiving a share of sunlight at some stage during the day as the sun traverses the sky.

In contrast, indoor cannabis plants receive illumination from a stationary grow lamp positioned above. This makes naturally-shaped cannabis plants inefficient to crop indoors, unless you cultivate in large numbers using the SOG or Sea of Green method. Topping is the method of choice for pro growers to increase yields. It is also favoured by home growers that want to fill out their grow space with a handful of plants, rather than pack in as many as possible.

Removing the terminal bud will encourage the development of two new main colas and promote growth of the lower, secondary branches. The aim is to invert the Christmas tree shape to allow more light penetration.Growth hormone is diffused to all of the shoots once the apical bud’s dominance is removed. Branchy, low-profile plants are more desirable to every grower. Indoors, vertical space is often at a premium and outdoors, bushes are stealthier than tall trees. Topping is a great technique to take control of the cannabis canopy.

WHEN TO TOP CANNABIS

Top your plants after they’ve developed between 3–5 nodes, as this is when their roots and stems are strong enough to recover from the stress of the process. Plants typically reach this size after around 30 days of vegetative phase. Be mindful that different varieties grow at different speeds.

Plants can’t handle topping during the seedling stage. If you try topping during this time, you risk killing or stunting your seedlings. Similarly, topping during the flowering phase is sure to cause damage to your precious plants.

Wait about 1–2 weeks before topping new growth. Your plants will require this time to recover from the stress and readjust to the new growth pattern.

HOW TO TOP CANNABIS

To top a plant, make a clean cut to the tip of the main stem using sterile scissors and fully remove the top growth. Be sure to leave about 5mm of space between where you cut and the lateral branches. This will give you slight room for error and help you avoid accidentally severing these important structures.

Instead of forming a solitary central cola, the plant will now grow two separate branches—the main cola will not continue to grow and the two side nodes will take over as colas.

You can repeat this process later on down the line. Eventually, the two branches you just created will be ready to top. This will further divide what was a single terminal flower into four distinct bud sites.

Continue the process until you’re satisfied with your plant’s canopy.

EQUIPMENT FOR TOPPING CANNABIS

Topping cannabis requires accuracy, precision, and cleanliness. Snipping your plant with a blunt tool can cause the stem to break and it can leave a much larger wound than intended.

Use the sharpest blades you can get your hands on. Office and kitchen scissors work, but they’re not as efficient as tools specifically designed for the job, so consider using pruning scissors. Razor blades are also a good option.

Try out these Curved Trimming Scissors made for taming and topping cannabis plants. The sharp blades and robust handle make them perfect for your needs. Their curved design makes them perfect for pruning deep within canopies and trimming off sugar leaves during harvest. You can also use this handy tool to obtain clean cuttings for cloning.

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WHAT IS FIMMING CANNABIS?

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.

LIMITATIONS OF TOPPING AND FIMMING

Topping and fimming will prolong the amount of time cannabis plants will need to spend in the 18/6 vegetative growth stage. Expect a 4-6 week vegetative growth phase if you plan on applying these techniques.

Another oft-overlooked and obvious problem with encouraging the formation of multiple fat colas is that marijuana plants tend to become really top heavy. In the absence of a ScrOG, plants may require staking with bamboo for support.

PRUNING AND TRAINING FOR MAXIMUM YIELD

Do you want the heaviest harvest possible? If you do, then you must be prepared to blend a few techniques. Topping or fimming cannabis plants alone is not really going far enough. Go the extra mile for those extra grams. By adding the following two methods to the mix, you might hit upon the recipe for a scale-tipping harvest.

LOLLIPOPPING

In brief, lollipopping is the removal of fluffy, lower bud sites from cannabis plants. The idea is to focus plant energy on developing big, fat nugs, rather than popcorn buds. Most growers like to strip away lower growth during week 3 of flowering. Pinching off is generally preferred to clipping away with a scissors. ScrOG growers will usually remove all of the lower growth beneath the screen to improve airflow and drive all plant energy to the tops.

SCROGGING

All of the above high-yield cannabis cultivation techniques can be further enhanced with a ScrOG or Screen of Green. A ScrOG is the pinnacle of high-performance marijuana growing. By deploying a mesh screen across the grow space, the whole grow-op is tuned for maximum production. Essentially, the grower must bend and fold shoots to fill out as many of the grid squares as possible. This begins in the vegetative stage and continues on until early bloom.