I've got a bunch of walnuts stratifying in plastic bags full of damp perlite in the refrigerator. Some of them have some white mold on the shells. Does this matter? If it does, what should I do about it? It will be a few months till I can plant them outside. The bags do have ventilation holes.
hau Gilbert, why did you put them in plastic bags with moisture?
most of the time walnuts do best when placed in dry sand then in the fridge to stratify them. In fact most seeds do better with dry stratification methods.
Take the walnuts out of the bag and see if you can wash off the mold. If you can, then dry them and from there do a dry stratification period.
If the mold won't wash off, toss those walnuts, they most likely will be damaged enough to not sprout.(or do a test run of sprouting them, you could be lucky)
Mother nature stratifies seeds by having squirrels bury the nuts and then makes the squirrel forget where it stashed the nut. Natural nut sprouting is a result of damp/ dry, cold/warm cycles like most winters are.