my daughter gave me a cascade rhizome last year and it seems that this year i will have a bunch of hops. I know that i can't bitter with it because i don't know AU but what do i do with them, dry hop, aroma, flavor?
Use them just as you would any other hops, though as you said you don't know the AA% so that does confound using them for bittering, not that I'd use cascade for bittering anyway. If you dry the hops you can use them weight for weight just as you would store bought hops, note though that if you use them fresh off the bine, or "wet" as many people call them, then you need to account for the fact that the hops are full of water. Hops lose about 80% of their weight when dried, meaning that 1 oz of dried hops is equal to about 5 oz of wet hops.