Aqueminianswered grow question 3 years ago If you want vertical growth do not prune, defoliate or top. Any of those training techniques are to create a bushier plant, it will slow down vertical growth. Now on another note, if your autoflower is growing very fast and you seen new leaves everyday then go ahead as it will recover very quickly. But you don't want to do any cutting to a slow growing autoflower. Check out my OG Diesel Kush autoflower diary for an example.