Q: I was at the Atlanta Botanical Garden the other day and they were in the process of putting out composted manure as a top dressing. They were not incorporating it into the soil but leaving on top and exposed. Is this something I should do?

A: The reason for applying a layer of manure on top of the ground is good: to attract and feed earthworms, which carry the material underground. This enriches and loosens the soil. If this were not done the soil would tend to become harder and harder and the Garden would have to dig up and amend their beds every few years.

I suspect that the secondary reason for applying the manure is a practical one: in winter there is little for the garden interns to do outdoors, so spreading manure keeps them busy.