Topping is a form high stress training (HST) that is debated between even the most experienced autoflower and photoperiod cannabis growers. While most concede that the process is beneficial for nearly all autoflowering strains, much of its effectiveness relies on knowing when to top your autoflowers, how to do it properly, and how often.
We’ve addressed all these questions and much more in this article as we teach you everything you need to know about topping autoflowers. Here, you’ll learn the overarching pros and cons of this form of HST, so you can determine if it suits your strain(s) and growing goals. You can then utilize our tips and guides for topping autoflowers and/or the alternative low stress training (LST) methods we’ve provided.
Do You Need to Top Autoflowers?
The short answer to the question is, no. Topping is just one of many forms of training you can use to benefit your autoflowers. While it might be one of the more highly recommended techniques for maximizing overall yield, there are several viable alternatives.
In reality, as long as you are caring for your autoflowers properly and meeting their needs, they will grow healthy without any form of training. Countless autoflower and photoperiod cannabis growers stand by the belief that untrained plants are best, so as to avoid stunting and unnecessary stress. Maybe this resonates with you more than using HST or LST.
Before you decide to top, or even train, your autoflowers, you’ll want to weigh the pros and cons of the technique while taking strain and preferred results into account. Only then can you decide if it’s the right choice for your plants.
Benefits of Topping Autoflowers
Autoflowers have revolutionized the practice of cannabis growing for their increased hardiness, high CBD content, and uncommonly quick production rate.
This comes from the careful crossbreeding of the C. Ruderalis strain (capable of surviving harsh climates and limited sunlight exposure resulting in shorter growing seasons) with high potency sativa or indica strains (both of which are significantly higher in THC than the C. Ruderalis).
Topping autoflower cannabis plants is a great way to enhance their natural benefits and potentially counteract some of their drawbacks, specifically reduced size and flowering period.
The most influential benefits of topping autos include:
- Denser buds
- Higher yields
- Promotes horizontal, homogenous growth
- Encourages plant to prioritize flower production over vegetation
- Improved airflow
- Increased resin production
Because autoflowers tend to be smaller in size and naturally grow in a conical shape with apical dominance like other cannabis plants, they tend to be smaller than photoperiod strains and are prone to smaller yields. Topping can counteract this by removing or shortening the central stem, which in turn limits the supply of auxins that promote vertical growth and allows the plant to grow outward and a rapid and vigorous rate.
Not only does this result in an even canopy for increased light penetration, but it is means you have a much shorter plant, which is ideal for growers with limited vertical space and/or are working with sativa strains.
Cons of Topping Autoflowers:
The benefits of topping your autoflowers can certainly be tempting, but there are some drawbacks that might convince you to avoid using this technique altogether.
The most notable cons of topping autoflowers include:
- process leaves the plant exposed to dangerous pathogens (especially when performed improperly and without taking necessary precautions)
- inflicts a significant amount of stress
- does not work on all strains
- requires the removal of the main central bloom (often responsible for 20% of total harvest)
It’s important to keep in mind that when you are topping your autoflower, you are creating a wound that can leave the plant vulnerable until the two new branches begin to grow. This risk is increased by the fact that topping creates a dense horizontal growth, which can harbor humidity and lead to issues like mold, mildew, rot, and bacterial infections.
As we mentioned previously, topping is also a form of HST that isn’t really “necessary” for the plant to grow and can be replaced with LST alternatives.
The last drawback of topping autoflowers that we’ll mention has to do with the specific strain you’re working with. Not all autoflower strains benefit from this technique. On average, strains with longer growing cycles, like those with sativa phenotypes, thrive from topping (when done properly).
If you’re attempting this form of HST on a strain with a faster life cycle, like Auto Berry or Auto Blackberry Kush, you might not notice much of a difference, or worse, the plant will suffer.
Why You Need to Top Other Cannabis Plants
If you have a strong preference for growing photoperiod cannabis plants over autoflowering cannabis plants, you might be wondering if the pros and cons of topping still apply.
In essence, topping other cannabis plants has the same benefits as topping autoflowers. You’re removing the apical meristem (where the auxin hormone is most concentrated) to encourage horizontal growth and double cola production for higher yields.
This technique also makes it easier to control the height and structure of your plants to suit the growing environment and your preferences. You can also expect to experience many of the same cons, with the addition that recovery might take longer for certain photoperiod strains.
One instance where topping a photoperiod cannabis plant can be more beneficial than an autoflowering plant is cloning. While autoflowers can be cloned, it is generally more difficult, and the results are rarely ideal. Photoperiod cannabis plants are often the superior choice for cloning, and topping a mom plant means you’re creating more shoots for potential clones (again, increasing your yield).
When to Top Autoflowers
Once you’re certain your autoflower strain will respond well to topping, the success of this training will hinder on proper execution. This starts with knowing when in your autoflowers life cycle to start topping.
There is some debate regarding when is the ideal to top autoflowering cannabis plants, but most growers agree that the sweet spot is after the tip has developed 3-5 nodes.
Some growers prefer to wait until they see six or seven nodes, but the risk here is that your autoflower might be in its early stages of bloom. Performing HST like trimming at this time could stunt their growth and/or inhibit their ability to bloom, resulting in smaller yields.
On the other hand, you don’t want to start trimming your autoflowers too early in their development, as this could shock its root system and stunt the plant permanently.
How Often Can You Top Autos?
The frequency that you can top autos really depends on the strain you’re topping, the plant’s overall health, and how proficient you are at the training process.
You can feasibly top your autoflowers once its developed those 3-5 nodes and you the new side shoots have grown from the previous top. However, that doesn’t necessarily mean you should top your plant.
Because this is a form of HST, it will likely take your plant several days or even weeks to recover, especially if you are topping multiple side branches at once.
If your strain tends to perform well when topped, it might recover faster, but even so, it isn’t wise to keep your autoflowers in a prolonged state of high stress. You’re better off incorporating other forms of LST or no training than to top your autos at every opportunity.
How to Top Autoflowers
If you’re new to growing cannabis plants, the idea of cutting away parts of your autoflowers might be unnerving. Topping is an easy process (in theory), but a few small mistakes can be costly, so it’s crucial to know how to properly top your autoflowers using the guide provided here.
To top autoflowers:
- Confirm your autoflower has the ideal number of nodes (3-5) and is healthy enough to endure topping
- Obtain a sharp pair of scissors or pruning shears
- Clean and disinfect your cutting tool
- Trim just above the leaf node on the main stem
After you’ve topped your autoflower, you’ll want to wait until the new side branches/shoots start growing before you repeat the process.
Tips for Topping Autoflowers
Whether you’re a beginner, intermediate, or expert grower, here are some tips to keep in mind to ensure topping your autoflowers goes smoothly and promote a speedy recovery for your plants.
Only Use Sharp, Sanitized Tools (No, fingernails do not count!)
The success rate of topping an autoflower largely revolves around when it’s done, but never underestimate the effect of doing it improperly. One of the most common mistakes growers make is using a dull and/or dirty tool.
Because topping is a form of HST, you don’t want to inflict more unnecessary stress on your autoflower. Using a sharp tool will guarantee a clean cut, which is easier for the plant to heal than if the stem had torn and jagged edges from a dull tool.
Ensuring your scissors or pliers are clean and sanitized will also limit the aforementioned risk of disease that is common with topping. This process already leaves the plant exposed, so the last thing you want to do is introduce bacteria into the wound through your tools.
Know the Difference Between Topping and FIMing
Another mistake new growers will make is that they will cut their autoflowers incorrectly and inadvertently FIM the plant instead of topping.
FIM aptly stands for “Fuck, I Missed” because it was born from a grower who did precisely as we described earlier. They attempted to top their plants, but instead of cutting almost directly above the leaf node, they cut off the tip of the main cola, leaving parts of the top behind.
The interesting thing here is that FIMing is it’s own form of training that you might even find is more beneficial than topping. Still, it’s important to know the difference between the two so you can care for your plants properly and better plan your yield.
Closely Monitor Recovery
Arguably the worst thing you can do when topping your autoflowers is assume that the process is done once you’ve finished cutting. In reality, the hard part has just begun for your plant.
Not only does your autoflower have to deal with the stress of healing an open wound and fighting off potential ailments, but it also needs to be strong enough to promote new growth from the cut.
You’ll want to closely monitor your autoflowers recovery the first few days after topping to ensure everything is going properly and, if not, that you can quickly respond to any issues that arise.
Other Ways to Train or Stress your Autoflower Plant
There might be a lot of support within the cannabis growing community for topping, but that doesn’t mean it is the be-all-end-all of training. If you aren’t full on board with using this method, there are countless HST and LST methods you can use instead.
Some alternative ways to train and stress your autoflower plant include:
- Super Crop
- The tie-down method
Each technique has its own pros and cons you’ll want to consider in addition to your degree of experience and knowledge before you decide to test it out on your autoflowers.
We’ve already touched on the technique of FIMing compared to topping as an alternative form of HST. To reiterate, FIMing is a variation of topping where you only cut or pinch off part of the main cola’s tip to promote the growth of several new colas instead of only two.
Itss pros and cons include:
|Promotes vigorous growthIncreased yieldsCreates four or more shoots versus twoLess stressful than toppingFaster recovery than topping||Inconsistent resultsHarder to create and maintain an orderly shape|
Another popular HST method is super cropping, which involves twisting the stem and branches of the plant to damage its inner herd while leaving the outer herd intact.
Its pros and cons include:
|Promotes vigorous, horizontal growthIncreased yields and potencyQuick and easy training method||Increases risk of disease or infectionCan kill plant when done improperlyProlonged plant recovery|
If you prefer to use LST methods, a great place to start is with SOG (Sea of Green) This technique aims to create a flat even canopy by growing multiple small plants in their own pots in close proximity (usually 1–2ft² ) of one another.
Its pros and cons include:
|Create a thick, even canopyFaster crop cycles than ScrOGHeavier yields than ScrOGLow crop heights||Must maintain more individual plants than other methodsRequires significant amounts of cuttings r seeds for optimal harvestsCan be difficult to reach plants individuallyHigh risk of disease spreading between plants|
Another method of LST that growers might use instead of SOG is ScrOG (Screen of Green). The overarching goal of this method is the same, but instead of keeping plants distanced from one another in their own pots, fewer plants are placed closer together and encouraged to grow around a large screen. This is most easily achieved with photoperiod plants by keeping them in the vegetative stage longer, but it can be done with autoflowers as well.
|Promotes horizontal growthIncrease yields Requires fewer plants than SOGProvides more control over plant height||More difficult to perform on autoflowers than photoperiod plantsRequires ample horizontal space for the screen and room for growthRequires regular maintenance until the plants top growing vertically|
The tie-down method is the most basic form of LST, and involves training plants by either gently bending it’s main stem or tying it down. The goal is to essentially teach the plant to grow in this position naturally so you can eventually remove its binding or stop LST altogether.
|The least stressful method of plant trainingDoes not inflict any damage on the plantCan be performed on very young plantsHelps open up the canopy and boost aerationEnsures all flowering sites receive equal amounts of light which increases yield||Requires regular maintenance, as you need to bend or tie down branches once or twice a weekCan be difficult to do properly, as each plant grows differently, requiring you to adapt to its structure (no exact guide)|
If you’re still interested in trimming your autoplants after reading this article, encourage you to use the tips and guides listed here to get started. Remember that while this can be an effective form of HST, the healthiest cannabis plants with the highest yields are often grown solely using LST or a combination of LST and HST. You can learn more about all these training techniques and more here on our blog.