Q.types of mulch
A thick layer of mulch on the ground around cherry trees may prevent the pests from burrowing into the soil, thus limiting new hatches. ( Controlling Western Cherry Fruit Flies Cherry Trees By: Mary H. Dyer)
When I look at mulches, there are a lot of different kinds, Which kind do I use for my Cherry tree?
Certified GKH Gardening Expert
Cherry trees are not picky about they type of mulch used. It will be up to you, depending on how you would like it to look. Some plants can be sensitive to type, but this will not be much of a concern here.