I wasn't able to find many threads regarding plants auto topping themselves. From the ones I read the main guess was it is due to the genetics of the plant. However, from previous experience in my grow tent with peppers and cucumbers, it appears the plants auto top themselves once they grow tall enough to be in the 'sweet spot' of the light for that particular variety of plant.
I have some cucumbers still growing along side my others plants, and they all appeared to stop growing vertically at almost the same level (about 3 feet tall, and 3 feet from the LED light). Once they hit this height, the cucumber vines starting putting out massive amounts of blooms/cukes, and the cannabis starting massively pre-flowering on one of the plants as well.
The last 6 inches of growth on the stems was anything but symmetrical. They started off with 2 sets of symmetrical stems on either side, then it just started shooting out stems with no pattern until it topped itself and started growing three new stems at the same level. I cut off the top at that point since I'm not looking for a single cola, especially this strain, as it is supposedly 100% sativa (mama thai). Still trying to decide if it's time to go 12/12 or if they need a little more veg time.
I haven't grown in several years, and the last time I did i was using HPS. Growing under LEDs now proves to be a slightly different experience.
I have some cucumbers still growing along side my others plants, and they all appeared to stop growing vertically at almost the same level (about 3 feet tall, and 3 feet from the LED light). Once they hit this height, the cucumber vines starting putting out massive amounts of blooms/cukes, and the cannabis starting massively pre-flowering on one of the plants as well.
The last 6 inches of growth on the stems was anything but symmetrical. They started off with 2 sets of symmetrical stems on either side, then it just started shooting out stems with no pattern until it topped itself and started growing three new stems at the same level. I cut off the top at that point since I'm not looking for a single cola, especially this strain, as it is supposedly 100% sativa (mama thai). Still trying to decide if it's time to go 12/12 or if they need a little more veg time.
I haven't grown in several years, and the last time I did i was using HPS. Growing under LEDs now proves to be a slightly different experience.
