I'm having this same issue, reeds,rose,dandy's all drop bags
Haven't tried other crops, and I've harvested at least 50 of each Wheat and pumpkin.
Also I can only seem to crossbreed reeds.
All won't work, I've had them set up for around 10 minecraft days and nights and have fertilized them all as well.
Sorry to highjack a bug thread but I assume its related
I seem to have these issues in 1.95 and 1.95b as well