TheCodeanswered grow question 5 years ago Yes, you can top auto-flowering plants that are growing fast and healthy as long as they haven’t started making buds yet. I top auto-flowering plants around week 3. If it hasn’t grown at least 4-5 nodes (pairs of “real” leaves) by the end of week 3, it may not be growing fast enough to handle topping without getting stunted.
When it comes to growing auto-flowering cannabis strains, there is a lot of controversy about whether they are compatible with the cannabis training technique known as topping (cutting off the tip of the plant while its young).
Some growers say you should never top an auto-flowering plant, while others claim they can top their autos without a problem. How can there be such a big difference in results between different growers? Well, here’s the thing about topping autos…. Auto-flowering cannabis plants are on a tight schedule! Most auto-flowering strains start flowering at 3-4 weeks, and have pretty much stop growing vegetatively by the time they’re 6-7 weeks old. It’s difficult or impossible to change the strain’s individual time schedule. It still takes a few more weeks until buds are ready for harvest, but in that time an auto-flowering plant generally won’t be growing new leaves and stems.
An auto-flowering plant is “full size” at just 6-7 weeks from seed!
Topping auto-flowering cannabis strains is often not recommended because they’re on a tight schedule and may not recover in time, but it can be done if your plant is growing fast enough during the first few weeks of growth. Auto-flowering marijuana strains have a short timeline, which is why it's usually recommended not to top them.
And on top of all that, you don’t need to top your plants to get multiple tops. Autos can grow with just LST/bending and they all will have multiple tops.
All that being said, sometimes topping an auto does go well. If you have a really healthy, fast-growing plant, topping it may not stunt it at all.
In some situations, topping may produce a better structure and increase yields!
So it’s not a matter of whether you should or shouldn’t top autos, as much as a matter of evaluating your situation and deciding if the reward is worth the risk for you!