Ammend, ammend, ammend. Your soil is probably compacted from the construction as well as being backfill. Without knowing your zone, the aspect (n-s-e-w) and other details of the area to be planted, the best advice is I can give is to dig up and add as much organic matter to the crappy soil before you plant anything else. This will give whatever you plant a chance at survival. PS--were the new plantings watered?

I have several ideas for you because I have lived in a series of houses with much the same problem (boo hiss!).

First of all, your best bet is definitely to change the composition of your soil. You can dig into your soil and amend it the traditional way, or you can top it off. I just bought a house with NO flower beds at all, and rather than digging out spaces to put them, I simply killed the grass and covered it over with a lovely load of amended topsoil. The whole topsoil order (five cubic yards) cost a mere $140 and was enough to do several beds at a depth of more than 1 foot deep. Everything I planted has done wonderfully. Even the oakleaf hydrangea (which can be a picky bugger) is exploding in new growth--it's now about three feet bigger than when I planted it in July.

Your other option is just to plant things that will surive in the soil as is. Yes, this can be done, depending on your climate and sun level of course. I have done it and succeeded, much to my own surprise.

I rented a townhouse for several years and did not want to put any money in amending someone else's soil. But I wanted a garden anyway, of course! :) The main bed faced east and got full, baking hot sun most of the day. The soil was rock hard. It probably had not been amended (or even touched) in forty years. And yet several plants did really well:

--rosemary
--lavender
--forget-me-nots
--feverfew
--thyme
--oregano
--marjoram
--borage

Everything else suffered horribly. But these plants absolutely thrived.

If you're not into herbs, one other idea is to plant moss rose (Portulaca). Portulaca hates to be watered. Portulaca hates nice soil. Mine have done brillantly with almost no watering; a six pack of tiny plants has spread to a carpet about a foot wide and eight feet long.

Hope this helps!

Here is a link that might be useful: {{gwi:47511}}

Compacted soil
not watering (the plants dried up)
facing southwest
zone 7

You can either try to find things that can handle the soil conditions, not getting watered, and the full sun, or you can change all three of those conditions by adding amendments, adding shade, and watering.

Since you asked for things that will thrive in these conditions, it sounds like you don't want to add shade, change the soil, or water.

Try ornamental grasses.

Azaleas would not be happy there, but the juniper might have made it. Whatever you plant, you would usually need to water it well for a year or 2 to get established, then if you had chosen drought-tolerant things they would likely hold up.

I have a rare oportunity to redo my yard for free. However there are some mountains I need to climb. The yard gets direct sun 80% of the day and the ground is almost always moist-wet it's dry just about every leap year. My biggest problems are errosion and mosquitos. Any suggestion an plants with a strong root system that can help keep the house where it is and hopefully keep the mosquitos at bay?

You should start a new thread with your question.