more important than how long they are look at the color. you want them white and thick. let them build a nice amount of roots before you plant. Soak what ever median you are using in clonex solution and use the clone ex gel. one way to do it is to keep a shot glass half full of the gel and as you cut off your mother just put the cuts in the shot glass to soak in the gel. once you get like 10 or 15 cuts start pluging them into your cubes. keep your clones in a warm place and let them dry out after a week or so. you will see them push fat roots when they start to dry out. once you see a good amount of roots hit them with a lite dose of rapid start