i would plunder through that thing and toss any daffodil bulbs you find over to the side. then put in some new soil, maybe stir it up a bit and replant the daffs if you want them back in there. fall is the time for planting bulbs.
if you jsut cover them up you may get them too deep and they...
i think a big yeller hibiscus would love that greenhouse!
Joe, what do you use your old truck for? you could make a chicken coop out of it...
maybe even a greenhouse!