how to top cannabis plants

Topping Cannabis Plants – Why, When and How

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  • Escrito por : Ciara
  • 12/11/2020
  • Crop articles
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Topping cannabis plants is an old method used both indoors and outdoors that consists in essentially cutting off the top part of the plant. This is done to stop growth and force your plants to grow more branches rather than growing vertically. For each cut that you make, two Y formed branches should grow, and the plant will recognize both branches as “central” stems. Don’t worry about losing yield using this method; the two new apical branches will produce a larger quantity of smaller flowers.

Cannabis plants tend to naturally grow with a sort of pine, Christmas tree shape. This is essentially due to the fact that they’re genetically designed for being tall, skinny plants. You can use methods included low-stress training (LST) in order to train the branches outwards and make for a wider plant, although the best possible way to cause the plant to stop growing vertically is to top the plant – remove the entire upper part of the plant.

Auxins are the hormones that seem to be in charge of the shape cannabis plants’ take; the tip of the main stem is where the auxins are produced, flowing down through the plant and stopping it from producing lateral growth. These auxins find it harder to reach the bottom of the plant, which is why when plants grow taller the lower branches grow out wider, giving them their classic Christmas Tree shape. However, topping allows you to remove the Apex (the top growth tip) and therefore break apical dominance, allowing side branches to grow more.

Topping Cannabis Plants: Why?

One of the main reasons for topping cannabis plants is lack of space or discretion; cannabis can grow to be quite tall, and sometimes low-stress training simply isn’t enough to keep them down, whether you’re trying to keep them away from prying eyes or if you’re trying to fit them into a small grow room or tent.

Plus, successfully topping cannabis plants can also lead to quite a large increase in yield, especially outdoors and combined with a SCRoG when growing indoors. This pushes a lot of people to maximize their yield via the topping technique. Thanks to this method, you can fill out your trellis net, making sure that the light reaches each and every branch. This makes for amazing buds at the tip of each branch, maximizing your harvest.

How to Top Cannabis Plants

Once your plant has produced 5 to 7 leaf nodes it should be strong enough to top. Keep in mind that this is a practice that stresses out your plants, so you’ll need to ensure that they’re as healthy as possible before beginning. You don’t want to top too low either, as depending on the strain auxins may still be present when regrowth occurs, causing vertical growth again.

The general rule to follow is to cut your plant above the 5 th leaf node in order to make sure that it’s sturdy enough to deal with the stress. You’ll also want to wait until your plants are at least 30 days old. This also leaves you with a decent amount of lower branches that can now grow outwards. Once you’ve topped once, you can keep topping both branches created, although make sure to top above the second or third node in order to give them time to grow out sturdy. Secondary toppings are usually only done by professional growers looking to grow absolute monsters outdoors and maximize yield.

First, you need to grab your tools and make sure to clean them thoroughly. You’ll need your sharpest pruning scissors for this, as you’re looking for a clean cut. We highly recommend sterilizing your tools before using then – they come into contact with the plant in a way that could cause infection of they contain any bacteria.

Pick out the spot you want to cut. Topping requires you to get rid of the newest growth from the main stem entirely, completely removing the top of the plant. Topping creates two brand new branches that sprout from the cut, although there is another more risky method called fimming with can create up to 8 new stems.

Once done, make sure to keep a close eye on your plants to make sure they’re recovering nicely. If cutting outdoors we highly recommend using plant sealing paste in order to prevent any possible infections; these types of cuts make it really easy for fungi and bacteria to get to your plant.

Topping VS Fimming

Both of these techniques are often confused; while they may be similar, they actually produce widely different results.

Topping involves cutting off the top of the plant from the stem, above a leaf node. Fimming, however, is a clean cut through the new growth on the top of the plant. This technique is considered to be less harsh and traumatic for your cannabis plants, although it does require extensive plant training afterwards as the new stems created by this method can grow out quite weak. The term FIM actually comes from the phrase “f**k, I missed” and it’s thought that the first person to try this technique actually made a mistake when attempting to top their cannabis plant. The FIM technique is done by grabbing the top of the plant and removing about 75% of the tip of the plant. It may not be the prettiest pruning method, but it is highly effective. It’s great for those with 1-2 plants in a small growing room. Keep in mind that fimming doesn’t actually slow down vertical growth as much as topping does.

A topped cannabis plant produces two extra stems that act like apex stems, producing thick and dense cannabis flowers. Fimming can produce up to 8 new stems that need to be trained; it’s a great way for novice growers with small grow tents to add a little extra to their yield.

Learn about topping cannabis plants, why it's beneficial for your plants and how it creates compact plants and helps increase yield indoors.

Marijuana Pruning: Topping Vs Fimming

Do you dream of long-running, resinous, chunky cannabis colas? Make it a reality in your marijuana garden with high-yield cultivation methods. Topping and Fimming are two proven techniques. Keep reading to find out which one is the best method for you.

  • 1. What is topping cannabis?
  • 1.a. When to top cannabis
  • 1.b. How to top cannabis
  • 1.c. Equipment for topping cannabis
  • 2. What is fimming cannabis?
  • 2.a. When to fim cannabis
  • 2.b How to fim marijuana
  • 3. Limitations of topping and fimming
  • 4. Pruning and training for maximum yield
  • 4.a. Lollipopping
  • 4.b. Scrogging
  • 1. What is topping cannabis?
  • 1.a. When to top cannabis
  • 1.b. How to top cannabis
  • 1.c. Equipment for topping cannabis
  • 2. What is fimming cannabis?
  • 2.a. When to fim cannabis
  • 2.b How to fim marijuana
  • 3. Limitations of topping and fimming
  • 4. Pruning and training for maximum yield
  • 4.a. Lollipopping
  • 4.b. Scrogging


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.


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.


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 5cm 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.


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.

Top and FIM your plants with accuracy and ease using these Curved Trimming Scissors. The sharp blades slice through cannabis stems without leaving a mess behind—allowing plants to recover swiftly.

Top and FIM your plants with accuracy and ease using these Curved Trimming Scissors. The sharp blades slice through cannabis stems without leaving a mess behind—allowing plants to recover swiftly.


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.


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).


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.


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.


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.


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.


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.

Push your marijuana into maximum overdrive with high yield pruning methods. This one is all about Topping and Fimming cannabis plants.