Dry shade can be a real challenge. Trees, no sun, bone dry soil. Pick the right plants and you can still create a beautiful space.
Dry shade is common here in North Carolina where large, mature tree canopy is predominant even in the urban setting. The soil under large tree is bone dry because:
You don’t need a stand of trees to have dry shade. You may also find it on the shady side of your home. House eaves block large amounts of rain from falling on the ground immediately under them.
There are plants that will tolerate dry shade. However, you’ll want to at least improve your chances of having healthy thriving plant by mixing organic matter, such as compost, into the soil, thereby increasing the soil's water-retention. Sandy soils are like a colander and quickly losing whatever water may come their way. Mixing compost into the soil will greatly enhance the soils ability to sponge-up water and hold it for the plants to use.
If you would like a list of tried-and-true plants for dry shade, look over this chart “Shade Gardening” prepared by North Carolina Cooperative Extension service.