Here's the deal: I have a nice swamp house, and I herb my fingers off all day long. But of course I can't grow crops, so that onion quest just sat there in my questventory until I lately got a friend with a vanilla house. So I grew my onions and got my badge. Sweet!
But I think there's a potato quest next, and the rock won't give it to me! I have Gardening 1-4 and Croppery 1-3 and I've done the onion quest. So why can't I get the potato quest? >.<