if height is a issue topping wont help, like someone else said, tying down the top of the plant to the lowest point you can will make it bush out and shorten the overall height, i would tie it down, wait a day then flip to flower. this should give you the vertical space you need. all topping is going to do is make the plan Y out it wont fix your height problemyeah, ive thought of it. Since this is my first grow, i didnt want to fuck about too much though. Theres alot of info in growing, so thoght id keep it as simple as I can.....wasnt even going to top them, but needs be....