Curious as to when I can top for the first time. Plants are 16 days old. 3 have started developing the 4th node and one has started the 5th. Can any be safely topped yet?
I wait till the roots have filled out the container and until their are 6 nodes or so. The plant will recover faster when it's a bit bigger and has a developed root system. I usually mainline, so I'll top it at node 3 or 4, depending on which has the best growth. Top too soon and sometimes they get stunted.