Not sure if it's the MAC version or maybe I've just missed something but I've been playing for a good hour and haven't had anything to go in the Cropplot. Unlike my palm trees which I have a tonne of and they're growing fine. I also had a small glitch on one of the shark's visit where I thought he'd jumped onto the raft, but he was just floating through the raft and then I killed it.
Update: The "press E prompt to plant and harvest" wasn't coming up because the Cropplot was slightly under some stairs. Got it working now.