Take these tips from Vince Sims: The Garden Rebel!
Vince says: A plant is drought tolerant if it can survive a dry spell of more than 2 or 3 months without supplemental watering. This means that most native plants from regions that occasionally experience 2-3 months without rain (most of the continental US, for example), are drought tolerant.

To reduce the need for supplemental irrigation in your landscape, choose drought tolerant plants. If you want to eliminate watering plants altogether, select species native to your area... like these examples below!

Use these native plants in your yard!

Blue Plumbago Plumbago is an evergreen shrub with whip-like semiwoody stems that form a loose, rounded mound 3-10 ft high with a similar spread. Plumbago can be pruned to grow like a vine into a more compact mounded shrub, or left to sprawl with its long, gracefully arching branches. Plumbago flowers bloom most of the spring, summer and fall in various shades of blue (buy plants in bloom to get the shade that you want). A favorite of butterflies, plumbago also is one of the most popular flowering shrubs in Central and South Florida gardens.	Agave Common names include Century Plant, or American Aloe (it is not, however, closely related to the genus Aloe). The name "Century Plant" refers to the long time the plant takes to flower, although the number of years before flowering occurs depends on the vigor of the individual, the richness of the soil and the climate; during these years the plant is storing in its fleshy leaves the nourishment required for the effort of flowering.
Ilex 'Nana' Ilex 'Nana' is an evergreen shrub or small tree reaching 5-9 m tall, with smooth, light gray bark and slender, hairy shoots. It is commonly grown as a trimmed hedge, screen or windbreak. When used as an enclosing barrier, it is planted approximately 5 feet apart and allowed to grow together. Dwarf varieties like 'Nana' are perfect for foundation plantings and their drought and disease resistance make them ideal candidates for low maintenance landscapes. It's fast growth rate and small leaves make it a perfect choice for topiary.	Crown of Thorns Crown of thorns is grown for its long lasting, colorful petal-like bracts which surround inconspicuous little flowers. Although often grown in pots on the patio, this thorny succulent is perfect for rock gardens and sunny borders. Crown of thorns is salt tolerant and often used in frostfree coastal areas, even quite near the sea. As a low growing hedge, crown of thorns makes a formidable barrier for low growing trespassers.
Weeping Ilex Tree Used to decorate many a home in winter, these are perhaps the most popular of all ornamental berry plants. Their showy berries often last for several months and attract birds. Most compact and fruitful in sun, hollies will tolerate shade. They range from 1-foot dwarves to 50-foot trees. Useful as a hedge, barrier or background plant.	Juniper Parsoni Parson's juniper is a ground hugging evergreen conifer with flat, feathery branches and both scaly and needlelike leaves. Parson's juniper makes a great ground cover in seaside areas because it is very tolerant of salt spray. It will cover an area 2 or 3 ft in diameter in two growing seasons. This is one of the more popular evergreens for bonsai.
Juniper 'Blue Pacific' Shore juniper is a dense, ground hugging conifer with aromatic gray green or blue green needlelike leaves about a half inch long and borne in fascicles of three. The needles are soft but sharp-tipped. Shore juniper gets only about 12-18 in tall, but can cover an area 10 ft across. The female cones are spherical, about a 0.5 in. in diameter, and silvery or bluish black with a waxy glaucus bloom. The whole plant has a soft, feathery look to it.	Yucca Yucca or 'Adam's Needle' looks a little like a small palm, but is actually more closely related to the lilies. The evergreen leaves of Yucca are straplike, about 1 in wide and up to 2-3 ft long. The leaves are basal; that is, they all originate from one point, taking the form of a rosette. Excellent in rock gardens and as an accent among other perennials. Yuccas are very drought tolerant and do well in outdoor containers even without supplementary irrigation.
Purslane Purslane or 'Moss Rose' is a prostrate, trailing, multi-branched annual with semisucculent stems and leaves. It reaches about 6 in tall with a spread of 12 in. The reddish stems and the bright green leaves are thick and soft and juicy. Moss rose is a beautiful, bright colored, low growing annual that blooms all summer long with little or no care required. It is one of very few annual succulents.	Holly Burfordii Burford hollies look distinguished, with their glossy leaves and dense, handsome habit of growth. They are usually planted in a grouping as a hedge or border and sheared evenly; used this way, they are hard to improve on. Burford hollies are mostly seen at 8-12', but over time may reach a height of 20' or more. Lower branches may be removed on large specimens to achieve a tree form. Burfords berry freely and without pollination, and the fruit lasts for months, providing a food source for birds into late Spring.