My first cloning tries were of plants in flower (probably 5+ weeks, had buds already), as a last effort to keep a strain alive. Tried multiple different techniques, had a horrible success rate. Probably took 15ish clones and 2 rooted. Though i may have thrown some away that might have still rooted if given more time, but the ones that did took at least a month. I thought i was just horrible at cloning, but the 15 i took from vegging plants for my new grow had all but 2 root, plus about another 10 rooted just sitting in solo cups. So yeah, the longer in flower you go the bigger the pain it is, but they do grow crazy if you can get them to root.