[elli1]

My problem is being on a hill. Erosion has taken dirt from under the trees and we have roots above ground under the canopy. I would like to bring in dirt to cover the roots and plant something to hold the dirt in place, either a grass or ground cover.

Also consider other ways to control the erosion. Such as terracing, using timbers, rocks/boulders, diversions, etc.

I had good luck with a Bluegrass/ creeping red fescue grass mix underneath a large elm tree (in heavy clay soil) when I lived in central Oklahoma. Bermuda in the remainder of the lawn. Bermuda absolutely will not grow (satisfactorily) in heavy shade. The soil beneath a canopy never benefits much from rainfall so you have to be prepared to keep the area irrigated. At least the clay soil helps you out some with that!

You might also look into some of the liriopes ('Monkey grasses' as they're sometimes called.) They are quite hardy in zone 6 (Oklahoma), drought tolerant, semi-evergreen, will hold the soil well when they're established and do well in shade. Another plus is that you can set the mower to a high setting & mow them off to make fall leaf collection easier.

[rightly_dividing]

Thanks, I appreciate all help. It is terraced already in trouble areas. The dirt areas below the trees are a source of erosion and an eyesore. I like the trees but don’t like the exposed roots because there is just enough grass to require mowing, and mowing and roots are not very compatable. We had monkey grass in our hometown home. Boy it would spread if allowed to, but that may be an idea, plant monkey grass between the roots. There is a plant called cast iron plant that does well under tress and spreads which also may help.

[blau993]

I highly recommend the Lariopes for dealing with hillside erosion. Our house in Annapolis sits on a hill with a severe slope about 10 feet down to the water. The trees along that hillside are having the same problem — soil eroding out from below and roots exposed. We have embarked on a major hillside stabilization project, adding dirt around the trees and using Lariope to control the erosion. It works. The hillside is much more stable than it was a few years ago. I don’t know the type of Lariope we use (Frau Blau would know that), but it only grows to about 6 or 7 inches, and, for a border off the lawn, that is fine, so no cutting is necessary. The Lariope is also highly tolerant of shade.