Walk around the neighborhood or visit local publicly accessible displays to see what other people there in your area have looking good in such places.

Plants with shallow root systems--succulents come to mind--they are extremely popular right now and don't need much water.

Got a photo of the Privets?

This is a picture of one privet's canopy taken from my upper deck. One arborist said they are dying and don't bother with pruning or additional water. Another local company is offering some sort of deep watering treatment. I will miss the shade these provide if they become leafless, not to mention the fact that they somewhat obscure an extremely ugly building.
Thanks.

I have your problem, add in the huge poplar trees with roots coming up above ground, it's been impossible to get anything to grow. I have finally gone it pots and planters. I have begun making planters from redwood/cedar fence boards. All the plants I put in these planters are doing great. Here is a picture of my first planter. I am not an accomplished woodworker, but these were fairly easy to make.
Cheryl

Cheryl, that's a great looking planter for someone who is not an accomplished woodworker! You may need to upgrade your status :-).