some strains clone better than others! 1 that is hard to clone is big bud, for some reason the calux takes a bit longer to form the root base, your blueberry hase is sativa and is harder to clone than the white widdow! all this aside, of all the types cloned by me, i have never had a problem realy, just that when cloning 50 or more at 1 time was the time! meaning that it took 8 days diff from the first that rooted! not good for a timed system. sure you are not doing that many so take a few more than you need, and then some more so you have turnaround, so if you want 10, cut nearly 15/20 if you can, expect to loose 5 and have them all 3-5 days apart! good luck grass hopper