I will echo Ottawan. If I put 4 or 5 different varieties of cuttings in the same bag, some get moldy almost instantly, and other never have a hint of a problem. I generally have more problems with cuttings I receive from back east, than I do with my own cuttings. Not bragging, just observing. So some locations and/or some varieties may just have inherently more issues. On cupped cuttings, of late, I have been squirting the mold off, and then leaving the rooting box open to they dry out and have less issues.