I second you on the pea gravel. It looks nice for a little bit, but then you get all sorts of dirt and debris in there that you can't remove. And when you decide you want to get rid of it, it is a real bear to remove.

I don't know of any groundcover that could handle kids playing, part shade, and the shallow roots of a maple tree. Hopefully someone with more experience will chime in, but I think astro turf or that soft rubber they put on playgrounds these days may be your sturdiest bet.

(My first thought was creeping thyme, but I don't think it's all that durable with kids playing. Plus it takes a while to get established, and buying plugs will cost an arm and a leg. Even starting plants from seeds yourself could be a pretty time consuming process just to get enough plants in the ground.)

Good luck!

They make a playground product that looks like woodmulch, but is actually ground-up recycled tires. Its great for the kids to play on, a local preschool that I work with uses it on all of their playgrounds. I cannot remember the name, but I'm sure google can help.

Would grass not work? It's tough and natural and I can't imagine that the initial cost for preparation and sowing would be more than pea gravel or rubber mulch.

I'm no expert, but I grew up with grass lawns. I don't remember Dad doing much beyond periodic fertilizing and regular mowing, and the grass looked fine. Since you aren't looking for something pristine you could probably even skip the weeding and fertilizing :-).

If you are open to artificial materials, I second alison's suggestion of recycled composite rubber. If we are thinking of the same material, it's used on playgrounds in sheets and I also used it in tile form for my decking material. It's a nice play surface (kind of soft and springy) and environmentally sound.

I hear a lot of good things about zoysia grass -- supposedly more hard wearing than whatever it is we usually grow. (I'm not much of a grass person.)

I think when it's a small concentrated space like anabananany is talking about would get too much wear for grass. When you have a larger space like a proper lawn, each little bit of grass isn't getting so much traffic, and has more of a chance to recover.

That said, I've seen some tiny courtyard gardens that feature little squares of turf that look like jewels!

Alison's right; in a very small yard, with lots of kid use, lawn doesn't fare well. Also, assuming that maple is casting shade, let alone surface roots, it's a lot for grass to have to contend with.

I think the suggestions of the rubber-ish surface are good ones for kids. Keep the plants off on the edges where they won't get trampled.

I just discovered pine straw. I'm using it as a mulch. It doesn't move (stays where you put it), smells nice (not strongly pine) and is cushy underfoot. I'm really loving it.