I take clippings when I have at least 3" of a branch to work with. My system is aeroponics, I have a sprayer spray my clones 1 minute every 5 minutes 24 hours a day, 7 days a week. It takes a full 13 days to sprout a red diesel. My blue cheeses pop roots in 6 days, they have more sativa in their genetics. My red diesels are like diamonds in the rough well worth the extra work.