building a bed around a tree

I've been looking at a lot of your pictures and see sloped beds. I have an oak tree that we have to redo the bed around, and I'd rather not have a flat bed with edging. I want a sloped one that just blends down into the ground. Am I making sense? Like this!! http://davesgarden.com/showforumphoto.php?imageid=5380

I need help in how to do that so the dirt doesn't just wash down. I really don't want to do it twice:)

Hmm, I'm not speaking from experience here so feel free to be skeptical. I'm thinking a good mulch is probably key to keeping the dirt in place. Either that or keep the slope very gentle. Some of my beds slope a bit, but I haven't had any problems with dirt creeping significantly. But if you want as steep a grade as in Tigger's picture, mulch! Better yet, email Tigger for advice... ;o)

tiG,

How about a low-growing mondo grass to use as edging. It's roots will catch any dirt. I use a variety of grasses for this since my yard is all downhill (I'm thinking positively). Water runs badly in the spring rains here. Monkey grass, which I'm sure you can get plenty of in your own neck of the woods, is also another option. There are some that don't get too high.

Some of the mondo grass in my yard is only 3-4 inches high.

Want some? Come on over and dig to your heart's content.

oh no!!!!!! you're not pulling that one on me!! That's what we're digging up to make a nice sitting area around this bed I want!!! It took over:( It really helped make a hard cement like area workable, but I will never get it all out. I just love the look of Tigger's, so I guess I better go right to the source. it's exactly what I want!