Backyard Designs

Avatar_Sean says:

Rocks are generally better for simply accenting the plants as decoration and for controlling weeds to an extent. But if you are looking to make your plants grow better, mulch is a better choice because it helps to retain moisture and such. But since you said you plants will not be affects either way(I hop you are right), rocks will be better for you.

nabbynurtz says:

I think a little of both would work.

contester says:

Keep in mind that debris can get down between rocks, compost itself and form enough soil that weeds will sprout through the rocks, even if you have fabric under them. I advise you only use rock if your yard is fairly clear of trees that drop leaves or if you have a leaf blower that you can reverse to use as a vacuum every fall.

hong kong says:

i would say use some mulch and put rocks around the drain.