I'm afraid it looks like Botrytis infection (bud rot).
Serenade Garden disease control spray is an organic fungicide Bacillus subtilis that sounds like it is safe to use on MJ, or you can make an organic fungicide of 1 tsp.
baking soda and 1/4 tsp. horticultural oil mixed in 1 qt. warm water. Spray frequently on suspected botrytis victims.