A tree is the hardest thing to replace in a landscape, and shade is the cheapest water-saver there is, cooling the soil and cutting evaporation for everything beneath it. The best low-water trees for the cold interior West are bur oak, common hackberry, pinyon pine and Rocky Mountain juniper; for the desert Southwest, desert willow, palo verde and mesquite; for Texas, cedar elm and Texas red oak. Below they're organized by region with zones, size and water, followed by the part most articles skip: how to water a tree through establishment.
One rule applies to every tree here: none of them is drought-tolerant as a sapling. CSU Extension notes that many woody plants need at least two growing seasons to establish, and shade trees often take longer. Drought tolerance comes from a deep, wide root system, and that takes years of deep watering to build.
At a glance
| Tree | Zones | Water once established | Mature size (H × W) | Region |
|---|---|---|---|---|
| Bur oak | 3–8 | Low | 60–80 × 60–80 ft | Cold West, Plains |
| Common hackberry | 3–9 | Low–moderate | 40–60 ft | Cold West, Plains |
| Kentucky coffeetree | 3–8 | Moderate while young, then low | 60–75 × 40–50 ft | Cold West, Plains |
| Honey locust (thornless) | 3–8 | Low–moderate | 30–70 ft | Cold West, Plains |
| Pinyon pine | 5–8 | Very low | 10–30 × 10–20 ft | Colorado, NM, Utah |
| Rocky Mountain juniper | 3–7 | Very low | 20–30 × 8–15 ft | Cold West |
| Gambel oak | 4–8 | Very low | 20–30 × 15 ft | Colorado, Utah, NM |
| Hot Wings® Tatarian maple | 4–8 | Low | 15–18 × 15–18 ft | Front Range, Utah |
| Chinese pistache | 6–9 | Low | 25–40 × 25–35 ft | Transitional, Texas, CA |
| Desert willow | 7–9 | Very low | 15–30 × 10–25 ft | Southwest |
| 'Desert Museum' palo verde | 8–11 | Very low | 20–30 × 20–40 ft | Low desert |
| Honey mesquite | 6–9 | Very low | 20–30 × 20–30 ft | Southwest, Texas |
| Arizona cypress | 7–9 | Low | 40–60 × 15–20 ft | Southwest high desert |
| Cedar elm | 6–9 | Low | 40–60 × 30–50 ft | Texas |
| Texas red oak | 6–9 | Low | 30–50 × 30–40 ft | Texas |
Cold and dry: Mountain West and Plains (zones 3–6)
Bur oak (Quercus macrocarpa)
Zones 3–8 · Water Low once established · Size 60–80 ft tall and wide
Slow, massive and nearly indestructible: the prairie oak that handles drought, cold and alkaline soil. Bur oak is a century tree; plant it where it has room.
Care tip: Plant a small container tree; oaks have a deep taproot and transplant poorly at larger sizes.
Common hackberry (Celtis occidentalis)
Zones 3–9 · Water Low to moderate · Size 40–60 ft
The tough shade tree of the plains, taking wind, poor soil and city conditions. It's a floodplain native, and the Missouri Botanical Garden lists medium-to-wet water, so in dry climates common hackberry is drought-tolerant once established but still appreciates a deep soak in long dry spells. In the Southwest, the smaller netleaf hackberry (Celtis reticulata, zones 5–9) is the drier-country choice.
Care tip: Water deeply every few weeks in summer for its first three to five years.
Kentucky coffeetree (Gymnocladus dioicus)
Zones 3–8 · Water Moderate while establishing, then low · Size 60–75 ft × 40–50 ft
A bold, sculptural winter silhouette and airy summer shade that lets perennials grow beneath it. It's tolerant of drought and alkaline soil once established, but it isn't a low-water tree in its first years: the Missouri Botanical Garden lists medium water. Plan on regular deep watering for three to five years.
Care tip: Choose a male (seedless) cultivar such as 'Espresso' to avoid messy, toxic pods.
Honey locust (Gleditsia triacanthos var. inermis)
Zones 3–8 · Water Low to moderate · Size 30–70 ft, by cultivar
Fast, filtered shade and tiny leaflets that disappear into mulch in fall. Choose thornless, seedless cultivars like 'Shademaster' or 'Skyline'. It's overplanted in some cities, so mix it with other species.
Care tip: Prune young trees to a single strong leader; they tend to form weak forks.
Pinyon pine (Pinus edulis)
Zones 5–8 · Water Very low · Size 10–30 ft × 10–20 ft
A compact native evergreen that's extremely thrifty once established, and the winter backbone of Front Range and Great Basin xeriscapes. Pinyon pine grows slowly and drops edible pine nuts in good years. See the Denver guide for local planting advice.
Care tip: Water evergreens monthly during dry winters for their first few years; winter desiccation is a common killer.
Rocky Mountain juniper (Juniperus scopulorum)
Zones 3–7 · Water Very low · Size 20–30 ft × 8–15 ft
An upright native evergreen with blue-green foliage, good for windbreaks and screening. 'Wichita Blue' is a narrower, silvery selection.
Care tip: Keep lawn sprinklers off it; junipers decline in constantly wet soil.
Gambel oak (Quercus gambelii)
Zones 4–8 · Water Very low · Size 20–30 ft × 15 ft
The scrub oak of the foothills, often multi-trunked, with russet fall color and big wildlife value.
Care tip: It spreads by root sprouts into thickets; mow or pull suckers if you want a single tree.
Hot Wings® Tatarian maple (Acer tataricum 'GarAnn')
Zones 4–8 · Water Low · Size 15–18 ft
A Plant Select small tree with scarlet summer seeds and red fall color, one of the few maples suited to dry, alkaline soils.
Care tip: Give it a deep soak every couple of weeks in hot, dry summers for the first few years.
Transitional and Texas (zones 6–9)
Chinese pistache (Pistacia chinensis, zones 6–9) gives brilliant orange-red fall color on modest water and suits Albuquerque, Boise's warmer sites and Texas. Cedar elm (Ulmus crassifolia, zones 6–9) is the tough native shade standard of Texas, and Texas red oak (Quercus buckleyi, zones 6–9) brings scarlet fall color on limestone soils. See the Austin guide for a fuller palette.
Hot and dry: the Desert Southwest (zones 7–11)
Desert willow (Chilopsis linearis)
Zones 7–11 (MBG: 7–9) · Water Very low · Size 15–30 ft × 10–25 ft
Orchid-like pink flowers from late spring through summer on a fast, airy native that hummingbirds patrol. Desert willow is rated zones 7–11 by NC State; the Missouri Botanical Garden is more cautious at zones 7–9. It's the signature small tree of Albuquerque, Las Vegas and St. George xeriscapes. Its hybrid, chitalpa (× Chitalpa tashkentensis, zones 6–9), reaches a zone colder but needs more water.
Care tip: It leafs out late in spring; don't give up on it in April.
'Desert Museum' palo verde (Parkinsonia 'Desert Museum')
Zones 8–11 · Water Very low · Size 20–30 ft × 20–40 ft
Green bark, a long yellow spring bloom and filtered shade, with no thorns. It's the default shade tree in Phoenix for good reason. The native blue palo verde (Parkinsonia florida) is similar but thorny.
Care tip: Water deeply and infrequently; frequent watering makes it grow too fast and break in wind.
Honey mesquite (Prosopis glandulosa)
Zones 6–9 · Water Very low · Size 20–30 ft × 20–30 ft
Deep-rooted native shade with a graceful, twisted form and fragrant cream catkins. In the low desert, velvet mesquite (P. velutina) fills the same role.
Care tip: Shallow watering makes a shallow-rooted tree that blows over; water deeply at the edge of the canopy.
Arizona cypress (Cupressus arizonica)
Zones 7–9 · Water Low · Size 40–60 ft × 15–20 ft
A fast, blue-gray evergreen for screens and windbreaks in the high desert.
Care tip: Give it room; it gets much wider at the base than a nursery plant suggests.
Watering a tree through establishment
Trees are the one part of a xeriscape that need deep supplemental water for years, and they're where most conversions go wrong.
- Water where the roots are. NMSU Extension notes that most of a tree's roots are in the top 18 inches of soil and can spread 1.5 times the tree's height from the trunk. Water at and beyond the drip line, not against the trunk.
- Deep and infrequent. A slow soak to 12 to 18 inches, weekly the first summer, then every two to three weeks, tapering over three years or more for shade trees.
- Move emitters out as the tree grows. Two emitters at the root ball the first year becomes a ring of drip at the canopy edge by year three.
- Water in dry winters. On the Front Range and in the Great Basin, a deep soak once a month when the ground isn't frozen and temperatures are above 40°F helps, especially for evergreens.
- Protect existing trees during a lawn conversion. CSU warns that established trees used to lawn irrigation can be stressed or killed by the "imposed drought" when sprinklers are turned off. Give them their own drip or soaker before you remove the turf.
- Plant small. A young container tree usually establishes faster and catches up with a larger one within a few years. Save the money for good soil prep.
- Mulch to the drip line, not the trunk. A 3-inch ring of wood chips, pulled back from the bark.
From our installs
On the Front Range, the tree losses we see most often aren't from drought; they're from lawn conversions that turned off the water a mature tree was living on, and from new trees planted too deep in clay. We set the root flare at or slightly above grade, never amend just the planting hole, and give every tree its own drip ring on a separate valve from the perennials, because trees need deeper, less frequent water. Hail and heavy spring snow break limbs on fast-growing trees like honey locust, so we prune young trees to a strong central leader. (Xeris Landscaping is owned by Xeriscaping.com's founder.)
Frequently asked questions
What is the most drought-tolerant shade tree for cold climates?
Bur oak is the most reliable large shade tree for the cold, dry West. Hackberry and honey locust grow faster but appreciate occasional deep watering.
How long do I need to water a new tree?
At least two growing seasons for small trees and three to five for shade trees, tapering gradually. Evergreens also benefit from winter watering in dry years.
Can I grow desert willow in Denver?
It's risky. Desert willow is rated to zone 7 and Denver is zone 6a, so it may die back or be killed in a hard winter. Chitalpa is a slightly hardier alternative for a protected spot.
Will removing my lawn hurt my trees?
It can. Trees that relied on lawn sprinklers need their own irrigation before the turf comes out. Set up a drip ring or soaker loop and water deeply every couple of weeks in summer.
For the layers beneath your trees, see drought-tolerant shrubs and dry shade plants. If you're in the Pikes Peak region, xeriscaping in Colorado Springs covers local tree choices. Check your hardiness zone before you buy.
