Not the quickest for me. The main tops always took 2x longer and harder to root then cuts taken from the lower nodes. I've had many more failures with main tops then lowers. The plant was about 3' tall when I took the cuts. I rooted them in RR under a dome then transplanted when roots where poking out.. I don't keep moms either. Since I couldn't run the plant I took 2 big cut then gave the plant to a buddy.