Selection criteria: Plants chosen for this list have the following features: 

1. They need fewer waterings than typical lawn grasses.
2. They can tolerate, resist, or avoid drought AFTER they are established.
3. They have attractive ornamental features.
4. They are relatively easy to grow.
5. They have not been invasive under our growing conditions.
6. We like them (well, there are some exceptions to this rule).

Watering requirements: Most of the plants on this list will require supplemental irrigation in the dry Inland Northwest. The water requirements of these plants vary by species and by the size of the plant. The amount of water that you will need to apply will also depend on your climate, soil type, and sun exposure. It is affected by cultural practices, including how you water your plants, whether or not you use mulch, and where windbreaks such as fences, walls, and other vegetation, are located. All plants require regular watering until their roots are established. For perennials, this means that they will need water on a regular basis at least during their first growing season. Trees and shrubs may require regular irrigation for up to three years after transplanting. 

Additional information:

• Water Conservation in Gardens and Landscapes, a WSU drought advisory.
• Xeriscape Principles for Landscape Water Conservation, from Texas A&M.