Heck, you can throw down some compost/soil and plant right on top, if it comes to that. No, really. I've got a whole shade bed planted on an old gravel parking area that never got used for parking. (So it wasn't compacted.) I put several inches of composted leaves/manure down, mixed in a little topsoil, and planted it up. You should SEE the hydrangeas this year! If I can find hte digital camera (it has gone walkabout again) I'll post some pictures. THAT said...I do feel your pain. I have that nasty white landscape rock down over black plastic in places in my back yard. I hate and despise it...and as soon as I have A Plan I'm going to dig it up and get rid of it. DH tells me I may not mess with it until I have A Plan. (Capitals and all.) melanie

A top dressing is usually used for showing plants or for C&S. Used with a clay pot you can usually tell if a plant needs water by the color of your pot. I have most of my plants right now with a top dressing because I plan on showing them in two weeks time, but as soon as the show is over it is going to be removed. Some houseplants do benefit from a top dressing, but most of those are succulent like Sansevieria or the larger Crassulas. My pony tail palm and fockeas has a top dressing. It does make them look nicer and helps keep the moisture in the soil longer, but if you're prone to overwatering, this could be a problem. If you do use a top dressing, use a light brown with no dies, and a pebble size about 1/4 -1/3 in in diameter not smaller, and larger just looks funny on smaller plants.

there's no "purpose" to that layout, it's simply the previous owners idea of what's attractive - the mulch and gravel were no doubt intended as a visual transition that would keep grass and weeds from growing up into the rocks [temporarily] you won't have to plant anything on top the mulch, it's already happening on it's own as seeds sprout in it and grass roots run under it .... and anything you do won't "harm" anything, but I'd bet you're going to have a life time job pulling unwanted plants out of the whole works .... putting plants [and enough soil to support them] among the rocks will accelerate the process :) Bill

Helen your drawing made me smile:). I have the same crappy clay soil. First I dig the hole and fill it about a third of the way with my pumice/cactus mix, but I combine the crappy clay soil with my mix farther at the bottom. The more I fill the less I combine with the clay soil. Luckily most succulents roots stay fairly shallow. In fact I was digging a hole for an Aloe right next to my San Pedro and I couldn’t believe how shallow and wide their roots were. It’s all about that fast easy access to water. It’s all going to be trial and error. As long as you do your research on the plants first, you should be fine. Will some die? Yes. But others will flourish. Heck I’ve stuck some succulents in the ground without any pumice mix, and they’re doin fine. It’s usually the Aeonium, Aloe, Agave, and Opuntia that don’t seem to care much. Be careful of the sun because if the plants aren’t acclimated they will burn.