I only left the bags (plastic grocery bags) loosely tied one time on top to keep them from molding, didn't think about breathing. I thought only the leaves 'breathed' . I don't have zip bags big enough for the clumps so that will have to suffice for holding in moisture also.
Maybe I will do a check in a week or so and if they look a little dry, spritz, then tighten the tops. Those bags aren't as 'skookum' as zip locks so they might allow a little more in and out of air-humidity. Only 60 days and we are around the corner to spring. Bwahahahah