When I grow from seed I always top at the 4th node, but when growing from clone I usually wait a little longer. a) to give them a little longer to establish a root system, and b) because clones are usually brachier anyway. I've got some clones that are about 8 nodes and they still look to small to top. What are your opinions about this? When do you top clones?
I'll top & leave two nodes on the plant but I don't rush into it. The clones may have five nodes by the time I top and I just take more off. The two shoots from the top node grow fastest after topping because they're closest to the light, but waiting to top usually results in larger branches from the bottom node at the time of topping. The two top shoots are both topped, leaving one node on each. By the time these four shoots get going, the two shoots from the bottom node reach canopy level. The plants go into flowering with six stalks, each at almost exactly the same height.