If you’ve ended up here, there’s a pretty good chance that you already know what shape untrained weed plants typically end up taking. That classic Christmas tree look – a main stalk shooting up to the heavens with a bunch of branches reaching out horizontally, otherwise referred to as ‘apical dominance’.
While this shape has its advantages evolutionarily, and has ensured the plants’ survival up until this point, it does have its downsides. This type of growth leads to the top bud (or cola) receiving the bulk of the light, while those lower down fight for the scraps. It also means that certain strains, Sativas in particular, end up stretching out while they grow tall and thin.
So, what can be done to break this pattern?
How can growers ensure an even distribution of light and maximize their yields?
The answer is – topping. In short, topping is the process of cutting off the main shoot (also known as the apical meristem) of a cannabis plant in order to change the overall shape of the plant, force the plant into producing more budding sites by encouraging it to grow wider instead of taller.
There are a few key reasons why topping has long been the go-to method for growers looking to improve their yields.
Topping just makes sense from a practical perspective. By having multiple budding sites instead of one main cola, you’re going to end up with way more flowering sites, a reduced canopy height, a more even spread of light, and better air circulation – all reducing the risk if something goes wrong with any particular bud – be it mold, pests or anything else.
Topping is one of the easiest and quickest ways to train a weed plant, and it requires very little equipment. With that said, using the wrong equipment is a surefire way to end up with a suboptimal result, and you can even kill the plant if you’re not careful.
All you need is:
Now, this is where you’ll find conflicting information all over the internet. Part of training a plant is learning how it grows, and every strain will respond differently to different methods at different times during its life cycle.
In general, though, we’d recommend waiting until the plant has grown at least 5 nodes. This will ensure that the plant is strong enough to withstand the cut without any major setbacks. It also allows for more potential budding sites to form, leading to a more abundant harvest in the long run.
What’s a node?
A node point where a set of leaves meets the main stem. Once you’ve counted 5 nodes from the base of the plant, you’re good to go. Some growers like to let the plant grow to 6 or 7 nodes before topping at the 5th node, but in our opinion, this is overkill and will slow down the entire process.
As for when in the plant’s life cycle to top, it’s pretty simple. Topping must be done during the vegetative stage – once you’ve got 5 nodes and your plant is exhibiting strong, healthy growth. Topping your plant during the flowering stage of growth, you will end up with a smaller yield, and may even kill the plant. In fact, We recommend doing all heavy stress training during the vegetative stage, and treating your flowering plants like the queens they are.
We’ve hinted at how simple topping is, but what is the actual process?
Topping cannabis is a technique that yields the best results when applied to a strong, healthy and well-developed plant that can withstand significant stress. Topping puts a heavy strain on the plant and will result in at least a short pause in growth while the plant heals.
For the first topping:
That’s it, you’ve successfully topped your plant! The first. Once your plant has recovered, you can repeat the process one or twice more (if the plant can handle it and has a few more weeks left in veg before she starts to flower), and also depending on your goals.
This is an age-old debate in the cannabis cultivation community, and one that doesn’t really have a right or wrong answer.
Fimming or FIMing, which stands for “F*** I missed”, is essentially just a “failed” topping attempt – where instead of cleanly cutting off the top section of the plant, you accidentally miss and only partially remove it. This results in a slightly different effect compared to topping.
Where topping doubles the main cola, FIMing typically produces 3–4 colas instead. It can sometimes produce even more, but it does come with more risk. If you accidentally cut too far down the stem, you can end up killing off the entire top of the plant. It’s a risk versus reward situation, and ultimately it comes down to personal preference and experience. Some growers swear by fimming, but if you are just starting out on your growing journey and want to reduce the risk, we definitely recommend going down the topping route.
Having said that, if you are open to experimentation and have a few spare plants, why not give it a crack?
Topping autos is generally regarded as a bit of a no-no, but with how weed genetics have been heading in the past decade or so, some of the new school autos can definitely be topped. It’s all about how long a particular auto strain will stay in the veg period before starting to flower.
Autos that are bred to be batched out quickly typically have a short window for topping, and it is not recommended as they will likely end up spending too much time in recovery rather than putting on structure size. But, a quick glance at an auto flower’s timeline can tell us if it is worth trying our luck with.
How do you tell if your auto has enough time to top?
Check out the grow diaries or reviews of people who have grown that particular strain before, and pay attention to the timeline. You will want a decent amount of veg time left (ideally 2–3 weeks) before it starts flowering.
Fast flowering strains are different, as while they have had their flowering period reduced by a week or two when compared to the regular version, they are still photoperiodic strains. You have full control over the length of the veg period, meaning you can easily time your topping to perfection. Just remember, fast flowering strains can still take anywhere between 4 and 10 days to recover from topping, so make sure you leave enough time before flipping them into flower.
Topping is a great standalone technique, but to get the most out of your plants, you should consider combining it with other training techniques. Some popular methods include low-stress training (LST – otherwise known as ‘tying down’), super cropping, and using a SCroG net.
With our photoperiod and fast flowering plants, we almost always use a combination of topping, pruning, super cropping, and SCroGging. This combo works wonders for maximizing yields, increasing bud density, and improving overall plant health. Just remember not to hit the plant with everything at once.
Supercropping is where you gently and carefully pop the internal structure of the branches just above the nodes to weaken them, making it easier for the plant to redirect energy and nutrients to other parts of the plant. The result is a bushier and more robust plant with multiple colas. Set up your scrog net just after you finish topping, and then slowly train the branches out horizontally through the net and away from the main stem.
Another option is to run a Sea of Green grow where you top all the plants just once. This technique ensures the fastest harvest by packing in more plants per square foot and involves vegging the crop for just a few weeks before flipping over the flower production. Perfect for when space is limited, or you want a quick turnaround between grows.
With autos, keep the overall training to a minimum and allow the plant to do its thing. That said, a little LST can go a long way! Gently bend and tie down your plants’ main stem as it grows to keep it short and wide rather than straight up. Even just doing this will result in the plants’ growth hormones and nutrients spreading evenly through the branches, potentially leaving you with a bigger harvest.
Pruning should be part of your regular maintenance routine, whether you have topped that crop or not. By removing unnecessary leaves, bud sites, and branches, you enable your plants to focus all their energy on developing the most essential parts – the ones that will produce the biggest yield.
The same goes for topping. When you cut off the top of a weed plant, it forces the plant to redirect its energy and resources to lower branches, resulting in more budding sites and a fuller, bushier plant. Plus, with proper pruning techniques, you can ensure there’s enough air movement throughout the canopy, reducing the risk of pests, mold, and a whole range of other issues that can arise during the growing process. This extra space also allows way more light to penetrate the canopy, providing an ideal environment for healthy growth.
First things first, go grab that set of shears or trimming scissors. If this is your first time growing, you probably haven’t bought a set of dedicated trimming scissors yet. You can use normal scissors when trimming and manicuring your harvested buds, but you’ll have a much more enjoyable time using a more suitable pair of trimming scissors. Trust us on this one.
There are two main options to choose from, spring-loaded or manual. Fiskars are super popular, but there are cheaper options out there that are just as good. These from AC infinity do a great job, and you get two pairs for half the price of a single pair of Fiskars. We prefer manual trimming scissors, and this two pack from Yieldcropper Hydroponic are a great choice for those of you on a budget. Any of these options will work just fine, so don’t overthink it too much. You’ll also want to grab a decent set of shears to help you get through those thicker branches. With shears, we find it’s better to spend just a little more, and these Fiskars have a great balance between cost and quality.
How much does it cost to grow weed? Read our other article to find out!
After cleaning down all your tools, start from the bottom up. The lowest branches that are receiving almost zero light should be trimmed off. The buds that grow down there are simply not worth the effort as they are usually small, wispy, and not even worth smoking. By removing the branches, you’re allowing the plant to redirect its efforts to the higher, larger branches instead.
Next up, look for any lower leaves that are starting to yellow or die off. These are also a waste of energy and should be removed. Don’t go overboard, the general rule of thumb is to remove no more than 30% of the plant’s foliage in one go. This may differ depending on your growing conditions, so just trust your gut and use your best judgment.
While you’re doing all of this, give the plant a good once over. Check the underside of the leaves for any pests or eggs and remove them as needed. Pests love to hide away under the leaves away from the harsh light, so double-check to make sure you’re not missing any little nasties. Last but not least, any fan leaves blocking light from reaching your buds should be removed.
Again, this is a bit of a contentious subject. Weed growers are a passionate bunch, and many have their opinions on the best time to prune. Most people will tell you to prune early on in the vegetative stage, usually around week four. If you are growing outdoors, or running a long veg time for your indoor crop, you might want to hit the plant again at least a week before flowering starts. This allows the plant ample time to recover and adapt before focusing all that energy on bud production.
Pruning during the flowering period is also heavily debated. Some think that any pruning at all once full flower production has begun will stunt the plant’s growth, while others think it fine as long as you keep it light. We tend to side with the latter, as long as you’re only taking off a few fan leaves and not doing any heavy pruning, you should be okay. However, if in doubt, wait until the next grow before trying anything too radical.
Nope, in fact, you’ll probably end up with smaller buds, but the overall weight will be heavier. Think of it like this: instead of your plant producing one large tip cola, it will now produce two slightly smaller ones and a lot more side colas.
Not necessarily. Trichomes are primarily due to genetics, not pruning techniques. However, by allowing more light and air to reach the plant’s canopy, you may see an increase in trichome production.
It’s not 100% necessary, but it can be beneficial for maximizing yields and increasing airflow through the plant. Plus, it can help create an even canopy for more consistent growth.
This is a bit of a controversial topic in the cannabis community. Some growers swear by topping their autoflowers, while others believe it’s best to let them grow naturally without pruning or heavy stress training. Ultimately, it will depend on your growing style and preferences and the genetics you are working with, so do your research and experiment to see what works best for you. So, if you feel like topping your Amnesia Haze auto then please be careful but don’t let that deter you.
Topping is one of the easiest and most straightforward plant training techniques, making it a popular choice for beginners and experienced growers alike. It should be a skill in the back pocket of every cannabis grower, ready to use when needed. But remember, less is often more when it comes to pruning and plant training, so always trust your gut and use caution when making any major changes to plant structure. When done correctly and at the right time, topping can help increase yields, improve airflow, and create an even canopy for more consistent growth.
Sam N. is a content writer with a passion for everything cannabis. After working multiple seasons on weed farms absorbing the ins and outs of cannabis cultivation and culture, he decided to transition into a role that would allow him to work from anywhere, anytime. Sam now writes for multiple weed publications. He has extensive experience with a wide range of canna-agriculture styles, from smaller artisanal farms to large-scale commercial operations, and is here to share his knowledge to give you all the best chance of cultivation success. About this Author