I waited three long years to pick asparagus and now I’m seeing tall ferns and wonder when they should be cut down.
It’s important not to over harvest a “young” asparagus bed. Never cut any spears which are smaller in diameter than a pencil and stop harvesting after 6 to 8 weeks. Let the rest of spears turn into fronds and don’t cut them until they turn completely brown. Next spring just before you think they’ll emerge, throw a thin layer of compost on the bed. That will feed them every time it rains.