I planted lots of greens in the hoop house in October, a few days before we put the cover on. They will grow very slowly because we're not getting a lot of light this time of year, but by Christmas we should be able to start to harvest out of the hoop house.
Here is a baby carrot. It'll probably be early spring when they're ready. Just after I planted the hoop house, we had 5 inches of rain one day. It sort of scrambled the seed. My carrots and radishes are no longer in rows in the hoop house. I don't think they care, as long as they have enough elbow room.