A tree is the single hardest thing to replace in a landscape — and shade is the cheapest water-saver there is, cooling soil and cutting evaporation for everything beneath it. So choosing drought tolerant trees is the highest-stakes plant decision in any xeriscape. Get it right and you water a tree for two or three establishment years, then rarely again. Get it wrong and you're hand-watering a dying maple for a decade.

One rule before the list: every tree here needs regular deep watering for its first two to three years. There is no such thing as a drought-tolerant sapling — only drought-tolerant root systems, and those take time to build.

Cold and dry: Mountain West and Plains (Zones 3–6)

Bur Oak (Quercus macrocarpa) — Zones 3–8. Slow, massive, and nearly indestructible — the prairie oak that shrugs off drought, cold, and alkaline soil. Plant it for the next century.

Hackberry (Celtis occidentalis) — Zones 3–9. The tough, fast shade tree of the plains. Not glamorous, but it takes wind, drought, bad soil, and city life without complaint.

Kentucky Coffeetree (Gymnocladus dioicus) — Zones 3–8. Bold, sculptural winter silhouette and airy summer shade that lets grass and perennials grow beneath it.

Honey Locust (Gleditsia triacanthos var. inermis) — Zones 4–9. Fast, filtered shade and tiny leaflets that disappear into the lawn in fall — no raking. Choose thornless, seedless cultivars like 'Shademaster'.

Pinyon Pine (Pinus edulis) — Zones 5–8. Compact native evergreen, 15–30 feet, extremely thrifty once established. The winter backbone of Front Range and Great Basin xeriscapes — see the Denver guide.

Gambel Oak (Quercus gambelii) — Zones 4–8. The scrub oak of the foothills — often multi-trunked, 15–25 feet, with russet fall color and serious wildlife value.

Hot and dry: the Desert Southwest (Zones 7–10)

Desert Willow (Chilopsis linearis) — Zones 7b–9. Orchid-like pink blooms all summer on a fast, airy, 20-foot native that hummingbirds patrol daily. The signature small tree of Albuquerque and Las Vegas xeriscapes. Its hybrid chitalpa stretches hardiness to Zone 6.

Palo Verde (Parkinsonia 'Desert Museum') — Zones 8b–10. Green bark, yellow spring bloom, filtered shade, thornless. The default — for good reason — in Phoenix.

Velvet Mesquite (Prosopis velutina) — Zones 8–11. Deep-rooted native shade with a graceful, twisted habit. Water deeply and infrequently to force roots down; shallow watering makes a shallow-rooted, wind-thrown tree.

Arizona Cypress (Cupressus arizonica) — Zones 7–9. Fast, blue-gray, evergreen — the low-water screen and windbreak tree for the high desert.

Texas and the southern plains (Zones 6–9)

Texas Red Oak (Quercus buckleyi) — Zones 6–9, brilliant fall color on limestone soils; Cedar Elm (Ulmus crassifolia) — Zones 6–9, the tough native shade standard; Lacey Oak, Mexican Plum, and Anacacho Orchid Tree round out an Austin-area palette. Crape Myrtle (Zones 7–9) earns its spot too — long summer bloom on modest water once established.

Small ornamental trees for any dry garden (Zones 4–8)

  • Western Redbud / Eastern Redbud (Cercis) — spring magenta on 15–20 feet; the western species is the drier of the two.
  • Amur Maple (Acer ginnala) — Zones 3–8 — one of the few maples that tolerates dry, alkaline sites; flame-red fall color.
  • Hawthorn (Crataegus, 'Winter King' or native species) — flowers, persistent fruit, and grit.
  • Serviceberry (Amelanchier alnifolia) — flowers, edible fruit, fall color; best with a little supplemental water in the driest climates.

Planting for drought from day one

  1. Plant small. A 15-gallon tree routinely overtakes a boxed specimen within five years, because young roots establish faster. Save the money for good soil prep.
  2. Water deep, wide, and infrequently — a slow soak at the drip line, weekly the first season, tapering through year three. Frequent shallow sips build the shallow roots that fail in drought.
  3. Mulch to the drip line, not the trunk. A 3-inch ring, pulled back from the bark.
  4. Skip staking unless it's windy, and remove stakes after one year — trunks strengthen by flexing.
  5. Water monthly in dry winters for the first few years, especially evergreens. It's the most-skipped task in cold-winter xeriscaping.

Choosing trees by zone first? Start with the hardiness zone guide, then build the layers beneath with drought-tolerant shrubs.