Can anyone suggest shallow-rooted shrubs or ground cover that would be suitable for planting over a septic leachfield? Our lot is heavily wooded, so the leachfield is probably too shady to support a decent lawn. Prior to recent repairs to the pipes, it had a covering of pine needles and straggly weeds. Now it is bare clay. The lot is sloped, so the depth of the pipes ranges from about two to four feet under ground.
Ideally, I'd like to use native plants (central North Carolina) but would consider non-invasive exotics. The soil is a fairly well drained red clay, and the trees surrounding the leachfield are mostly pines, sweet gum, and tulip poplars.
Would native rhododendrons work, or do they have deep roots? Any other suggestions?
Nick