It’s a running debate among growers, should you top autoflowers or not? Well unfortunately the answer isn’t a straight forward yes or no. It depends on a few things such as your level of experience and the autoflowering strain that you are growing.
Let’s talk through what you should consider when training weed plants before you go ahead with topping your autoflowers.
What is topping?
To explain what topping is and exactly how it works first you need to understand why it is done. Topping is done to break a cannabis plants apical dominance. Don’t worry it’s not as complicated as it sounds.
What is apical dominance?
The apical dominance of a plant is its inbuilt nature to grow with one tall main stem and other smaller branches coming out the side. The main stem naturally gets most of the plants energy and this is to allow it to grow tall and compete with other plants for the suns light.
Topping is a high stress training (HST) method used to train cannabis plants whereby you cut of the main central stem, preventing it from growing with apical dominance. You then bend and tie the other branches into favorable positions so that they each have an even share of the light. Instead of growing in a traditional Christmas tree shape, a topped autoflower will then grow laterally and produce a flat canopy.
Will topping autoflowers damage them?
The whole point of HST is that you interrupt a plant’s growth pattern by lightly damaging it, then allow the plant to recover, and hopefully the outcome will be a bigger and better plant.
The reason that many growers advise against topping autoflowers is because of their much shorter vegetative and flowering periods there is much less time for the plant to recover. If a cannabis plant does not have enough time to recover from HST before the flowering stage its yields will seriously suffer.
Going back to my original point, if you are planning on topping your autoflower because you have heard that it’s the best training method for increasing yield, you need to first take a few things into consideration.
What strain are you growing?
After topping an autoflower it will need a few weeks to fully recover, because of this it is better suited to cannabis strains that have longer growing times. If you want to try topping an autoflower, consider growing a sativa dominant variety. Sativa’s generally have longer vegetative and flowering stages.
Have you got any experience growing this strain?
Every cannabis strain reacts differently to stress so it’s important that you have some experience growing the strain before you top it. You should know the plant well so that you have a good understanding of its nutrient requirements, preferred light cycles, humidity and temperature. Remember what you are about to do is going to cause some stress to the plant, so the last thing you want is to cause any further stress by messing up its nutrients.
How experienced are you at growing autoflowers?
Autoflowering cannabis strains grow very differently to photoperiods, so before you decide to carry out HST training methods on them it is best to make sure you have at least a few autoflower grows under your belt first. Due to the risks involved topping autoflowers is something that even some experienced growers avoid.
Overall topping autoflowers can be done, and it can have excellent results if you know what you are doing and have experience with that particular cannabis strain. That being said, there are plenty of other training methods that you can use that inflict very little stress on your autoflowering plants so if you are more risk averse why not try low stress training instead.
How much can you yield from topping autoflowers?
This really does depend on lots of variations, such as genetics, pot size, nutrients, soil, light intensity and overall plant health. But let’s say that you are growing a huge yielding auto and manage to get all of this right along with topping your autoflower, you should expect to yield 200 – 300 grams off of one plant.
Pros of topping autoflowers
- Can produce much larger yields.
- Allows you to make the most of your grow space by filling up more of your grow room with less plants.
- Helps to limit the height of the plant which is perfect for any grower with limited space.
Cons of topping autoflowers
- Stresses cannabis plants.
- If not done correctly it could reduce yields.
- Risky for inexperienced growers.
How many nodes before topping autoflowers?
When cannabis plants are young, they are very delicate, you should wait until your autoflowers have produced at least 3-4 healthy looking nodes before you start any topping. At this point the plant is strong enough to take a little stress and this is early enough in the grow to allow plenty of recovery time.
How to top autoflowers in 2 steps
Remember before you start topping your autoflowers that we don’t want to cause any excess stress, so only top your plants that look healthy and have at least 3-4 nice looking nodes. If you see any telltale signs of an unhappy plant, such as droopy leaves, discolored leaves or dry looking leaves, do not top it until it looks 100% healthy.
Step 1: Topping your autoflower
Take a clean razor blade or pair of sharp scissors and make sure they are clean (run them under some boiling water to make sure). Next is the topping part. To do this you need to remove the apical dominance of the plant by cutting off the tip of the main central stem. Try to get a clean cut and be careful not to damage any other parts of the plant.
Step 2: Training the flat canopy
You can either leave your plant as it is to grow naturally from here, or to further train it to form a flat canopy you need to use LST or ScrOG methods. The most straightforward method of training your plant is to bend the side branches down and tie them in place. Most people drill some small holes around the edge of their pots and use rubber plant ties to hold the branches in place.
What are the best autoflowers to top?
Before you decide to top an autoflower you should choose a strain that has a longer growth cycle to allow for plenty of recovery time. Ideal strains are usually sativa dominant as they have much longer vegetative and flowering periods. Plus, the extra height you get from a sativa usually lends itself perfectly to the tie and bend training approach.
Amnesia Haze Autoflower
20 – 25%
500 – 600 g/sm
12 – 14 weeks
120 – 180 cm
Another sativa dominant strain, Amnesia Haze Autoflower is great for topping and can comfortably produce yields of up to 500 grams per square meter. It has a 10-12 week flowering time and is a robust and stable strain that responds well to high stress training techniques.
Read the full Amnesia Haze strain review.
Acapulco Gold Autoflower
15 – 18%%
300 – 400 g/sm
9 – 10 weeks
100 – 180 cm
Bred from an original landrace sativa, Acapulco Gold is a highly stable autoflower that grows long and tall and produces a bud that is a potent 24% THC. Reaching up to 180cm Acapulco Gold is an ideal candidate for topping where growers will be able to yield up to 550 grams per square meter if done correctly.
Acapulco Gold is one of the best exotic weed strains.
Super Lemon Haze
100 – 120 cm
Not only is Super Lemon Haze Auto a sativa dominant strain but she can also produce enormous yields and has a 12 week flowering period providing plenty of recovery time. Super Lemon Haze’s long branches are perfect for topping and LST and done correctly you will have very impressive yields. Super Lemon Haze is one of the best high yield strains.