Hello! I'm hoping that you can offer me some advice about what to plant.

We have a small area in front of our house, bisected by stairs. I really want a purple-leafed deciduous tree, and thought I had found the perfect one with a royal frost birch. I planted it last spring and it did beautifully all growing season. Unfortunately it never leafed out this year, and just today I found lots of evidence of birch borers. It seems I will need to replace it with something else.

I'm looking for a purple-leafed tree with a mature spread of 20' or less to fit between the stairs and the property line. Height is not an issue. It would be wonderful if it had interesting bark as well, and I'd prefer not to have something that's going to be messy (like the thundercloud plum). I also prefer not to have to prune if at all possible, and basically have a very low-maintenance tree. It will be planted on the west side of the house in full sun, in a slope. I'm in zone 6. The hardier the better, because I don't seem to have the greenest of thumbs, and we can get some nasty winters. Is there anything you know of that fits this bill?

Also, if you think a royal frost birch still might make it here and have any tips, I'd appreciate them since I really wanted that tree to work here. This was my first time planting a tree, and I think I planted it too deeply. It was planted as deeply as it was in the pot from the nursery, though I finally dug it down about a month ago and found the root flare about 3" down. If I planted a new one and planted to the appropriate depth, would it be likely to be healthy enough to resist borers (as this type of birch is supposed to do), or do I just give up on my hopes for this kind of tree here?

Thank you so much for your help!