Pour behind it, then let the material fall back, but don't pack. Depth only needs to be sufficient to keep the spores from drying out while starting, which would usually be 3 inches or less. Do not disturb the ground for some time after adding spores. Prevent vegetation from starting by pulling up if small, or cutting at ground level. If a crust forms, scratch the surface to let oxygen in.
Good drainage is needed, because standing water seals out oxygen.
Dried morels are available from American Spoon Foods in Petoskey Michigan. Other possible sources of dried morels are listed on the links page.