Especially when you want to pollenate an early flowering type with a late flowering type, Ursala. Then, when you need it, just take it out of the freezer, let it come to room temperature for an hour or so and use what you need. Then refreeze what you don't use.
Prominent hybridizers have told me that fresh pollen is good for about 30 days at room temperature. After that viability diminishes rapidly---so they say.
