We recently overhauled our Groundcovers web page to include more species listings for certain site conditions (like sun vs. shade, damp vs. dry). Though the lists are not exhaustive, they will hopefully provide some ideas, especially for areas prone to erosion if you use species known to be aggressive spreaders to they hold onto the soil quickly and effectively. The bulk of the species on that page are locally native, but not all; they are kept in separate lists to make that distinction.

Ideally, the existing grass should be removed first, since adding plants to established turfgrass areas may be challenging, in that they might not establish well, or will take longer to do so as the grass competes for resources. If you are unable to remove it, or can't hire someone to remove it, then you could try planting within the lawn and wait for the new plants to gain the upper hand and take over. A biodegradable cover on the soil, placed between new plants, can help reduce the risk of erosion until they can hold or cover the soil on their own. Untreated burlap and paper-based landscape "fabric" are two options that are probably among the best choices for a steep slope, where mulch would probably erode itself. Since they compost in place, they would not need to be removed later, unlike conventional synthetic landscape fabric.

Any new planting will need careful monitoring for watering needs as it establishes (even if the lawn is removed first), especially going into summer. A hired landscaping company might be able to help with this if it is needed.

Miri

Miri,

Thank you for the detailed response. I will talk this over with my wife and if we have any questions may I email you back?

Best regards,
Tom

Peace

You're welcome.
Yes, any follow-up questions (and image to share, if desired) can be posted in this same discussion thread.

Miri