hi! I started drying them well over a year before my wedding, and I would think as long as there isn't any moisture left in the petals they should be ok to keep for about a year. The blue came from hydrangeas!
I know you said it was a shoe box filled and a container but how many petals in pounds or liters did you have? I keep seeing them being sold by the liter and I want to see if they’ll be cheaper if I make them.
If I had to guess that might have been about 6 liters worth based on the container sizes? I don't have the exact measurement but might have been somewhere around that amount :)
Hmm maybe they weren’t completely dried before storing them, and as long as they aren’t smelling from mold, my guess is some perfume could help or more tea bags to absorb moisture and any odors! If they have gone moldy though best to start over to make sure they are totally dry before storing. Hope that helps!