Same thing here...growing two Apple Betty strain plants from seeds...stuff grows tall no matter what you do to train it not to...especially when starting flowering...the BIG STRETCH. I used bamboo canes, stuck them in the edges of the bags, 10 gallon bags, bend the branches and tie them to the canes using small zip ties...open up the plant spreading out the branches making it less tall, but it does take up more room horizontally. I was contemplating bring another one outside to grow but I already started tricking them indoors, and I'd rather finish the two indoors rather than have to climatize them gradually to the sun, then put them in the shed at night to cut the sunlight down so it won't reveg...trials & tribulations. How far are your lights from the plants? Mine get really close with zero issues, they're LED, not high pressure sodium...those close up will burn the tops but with LED you should be fine.