Choosing drought-tolerant plants is an important part of creating xeriscaping with low-water-use.
Although they are better than using non-native, water thirsty plants, there are still times when even drought-tolerant plants require extra watering.
During their first year even drought-tolerant plants need supplemental watering. Some may require additional water into the second year.
Only after the plants are established you can reduce or eliminate additional watering. Some plants will survive for many years without an extra drop of water from your hose.
Check each plant in your garden for clues to the water it needs.