There are many plants with water requirements less than grass capable of functioning as lawn substitutes. The main drawback of any is the potential for disease if the plant is not entirely happy. It would be good for you to get local advice about the plants that are trouble-free where you are. If the geometry and scale of your project works out such that it can be comprised of several species, then you can avoid putting all your eggs in one basket. (But, of course, the more species you add, the "busier" the appearance.) Since you are looking for a list of contenders, you might search "drought tolerant groundcovers" to explore the range and possibilities. Creeping phlox and some of the Sedums are two species of plants that come to mind. But there are many others. The list of possibilities to meet all of your needs is potentially extensive and highly dependent on your taste and the details of your project. Consider also if a plant can tolerate some foot traffic. If you narrow a list down, it will be easier to give feedback on it than it would be to generate a list in spite of so many unknowns. Many of the ordinary landscape plants became popular because of their toughness so don't overlook a plant just because it's common. Look around where you live and see what groundcovers are successful.

Keep in mind that success in implementing a plan for groundcover will be dependent on your ability to keep it weed free. This will take dedication, especially in the beginning.

You are probably vastly underestimating a comparison of required maintenance for lawn versus ground covers or mixed plantings, especially in a part of the country where woodlands are the default landscape. Lawn alternatives will require regular weeding to keep volunteer weeds and tree seedlings out, and require a higher skill/knowledge set to maintain than mow and blow lawns, so will probably cost more for monthly maintenance than lawn mowing.

I'd suggest you research local gardens in your town or a botanic garden with demonstration gardens of lower water use plants to see local regional possibilities, and also get more information on required maintenance levels. The trade-offs between lawn mowing versus weeding/pruning and dividing/end of season garden clean-ups are not clear until you look into it. Maybe posting this same question on one of the other gardenweb forums for your region will get responses addressing these trade-offs.

On the other hand, eliminating lawn from areas where it grows poorly due to intensive tree roots and deep shade from your maples does make sense. Looking for local examples or getting suggestions from a good local nursery on better plants and methods to use them may prove more fruitful.

Well, one plant that I have which I actually hate, and kind of sorry I got started, but which would be ideal for this application, is Lamiastrum, aka Lamium (I guess it was recently moved back into the genus Lamium). I hate it because it is uber-agressive and smothers out everything herbaceous around it in a few seasons. I made the mistake of letting it escape into perennial borders and now I fight it, it's hard to kill without consistent effort.

But I do have it in the original area under trees and shrubs in an island bed in poor clay soil, where it thrives, and it does make a great groundcover under there, no weeds at all, and it looks attractive all season unless there is severe drought, in which case it looks ratty and dies back earier than normal, but springs right back with water.

If you are looking for a straight green groundcover this isn't it, because it is heavily silvery-green-gray variegated. Does have attractive yellow early spring flowers typical of mint family plants.

I think when people contemplate ground cover, they always work within the assumption that the plant must crawl/root along the ground. But in fact, any plant that covers the ground (or any THING for that matter) at even a fairly high level can function to cover the ground and thus suppress weeds.

My favourite examples are always juniper and microbiota, which cover at ground level. But look under a huge rhododendron sometime, or some other shrub with low branches left to expand (or under a trailer that has been parked on dirt) and you will see little or no weed growth, just bare dirt. Many tree canopies serve as well - we get queries without number on the forum here from people asking what they can plant under trees because it is so bare. Lesson: canopies at a variety of heights will shade the ground and thus "cover" it.

When your brain begins at "grass" and explores "ground cover," one always thinks of about 6 inches above the ground. But in most cases, there is considerably more airspace above where the lawn was, and it can be used to much better OVERALL effect to shade the ground than a creeping plant can.

Karin L

White clover?

IMO there is no grouncover that has the equivalent functional utility of grass with respect to keeping the space available for active recreational use, foot traffic, etc. In the situation you describe, perhaps a better idea would be to assess where the grass does best and leave that (smaller) space as a lawn, planting the rest in a mix of plants (groundcover, perennials of various height, shrubs, understory trees) suitable for the shade, soil, water conditions that you have.