by J.E. Klett, C.R Wilson and S. Carter* (12/16)
Quick Facts…
- Select trees and shrubs for xeric landscapes based on both adaptation to Colorado’s climate and the ability to prosper in reduced water situations.
- Assess site soil, drainage and exposure before selecting trees and shrubs.
- Apply adequate water during the first years of plant establishment, then gradually reduce irrigation.
- Woody plants are a long-term investment.
Plants that will prosper in Colorado’s climate without benefit of ample irrigation require careful selection. This is especially true of woody trees and shrubs that are more expensive investments than herbaceous plants, both in terms of money and time to grow.
As a long-term investment, select and plant trees and shrubs only after careful evaluation of the site’s soil, drainage and exposure to heat and wind. While some xeric plants tolerate reduced water, they may not function well in soils low in oxygen. Many of the state’s dense clay
soils have minimal room to accommodate enough water and oxygen to meet plant root needs. Preparing soils by adding organic amendments prior to planting can often overcome water-oxygen concerns during initial establishment. Reduced water using trees and shrubs are best planted in
areas separate from lawns, unless lawns are also a reduced water use type. Regardless of how durable woody plants are for survival in xeric conditions, many plants need at least two growing seasons to establish. Water during establishment, then gradually reduce irrigation.
Adequate soil drainage plays an important role in preventing soils from water logging, which leaves no room for oxygen. Conduct a subsoil drainage test by digging an 18 x 18 inch hole, filling it with water and timing how long it takes to drain. Water that stands in the hole for more than 30 minutes indicates poor drainage. If amending the soil doesn’t solve drainage problems, drain tile or planting on berms (mounds) of well-drained soil brought to the site may be other solutions. Build berms to a minimum height of 24 inches.
Some trees and shrubs may perform poorly in hot south or windy west exposures and are better sited in cooler east or north exposure.
The following list of durable trees and shrubs will prosper in reduced water situations. For more specifics, check with your local extension office for the best plants for your area and microclimate.
| Table 1: Large trees for xeriscapes. | ||||
| Plant name | Height/ Spread (ft) |
Growth Rate | Comments | |
|
Acer negundo
|
40 x 30
|
F
|
Fast growing shade tree for harsh sites. ‘Sensation’ is a seedless male tree that doesn’t attract boxelder bugs, yellow to red-orange fall color. | |
| Catalpa speciosa Western catalpa |
50 x 35
|
M
|
Large, heart-shaped leaves with fragrant white flowers in June followed by long, thin seed pods. | |
| Celtis occidentalis Common hackberry |
45 x 45
|
M
|
Irregular habit when young maturing to rounded crown. Distinctive knobby bark. Trees shed leaves during drought. Red-purple berries. | |
| Gleditsia triacanthos inermis Thornless honeylocust |
35 to 55 x 25 to 45
|
M
|
Many varieties available that vary in size. Thornless and many varieties podless. Fine textured foliage turns yellow in fall. | |
| Gymnocladus dioicus Kentucky coffeetree |
55 x 35
|
S
|
Large compound leaves. Females bear seedpods that remain on trees through winter. Ridged bark, stout branches and coarse winter texture. | |
| Juniperus scopulorum Rocky Mountain juniper |
30 x 15
|
S
|
Native evergreen with blue-green foliage. Berry-like cones that are dark blue in the second year. Prefers full sun. Many varieties. |
|
| Koelreuteria paniculata Goldenrain tree |
30 x 30
|
M
|
Compound leaves emerge red turn to green. Yellow clusters of flowers in summer are followed by lantern-like fruit. | |
| Pinus aristata Bristlecone pine |
35 x 20
|
S
|
Native evergreen with dark pine green needles bearing white flecks. | |
| Pinus ponderosa Ponderosa pine |
60 x 30
|
M
|
Native evergreen with long, yellow-green needles in clusters of 2 or 3. Plate-like bark is cinnamon to dark brown. | |
| Quercus macrocarpa Bur oak |
70 x 60
|
M
|
Fiddle-shaped leaves borne on stout, corky-ridged branches. Adapts to alkaline soils. Distinctive fringed acorns. | |
| Robinia pseudoacacia Purple Robe’ locust |
35 x 25
|
M
|
Compound leaves emerge with purple tint. Dark purple fragrant flowers in May to June. Very susceptible to locust borer. | |
| Table 2: Small trees for xeriscapes. | |||
| Plant name | Height Spread (ft) |
Growth Rate | Comments |
| Acer grandidentatum Bigtooth maple (Wasatch maple) |
25 x 25
|
S | Small tree or large shrub. Tolerant of dry and alkaline soils. Dark green leaves turn red-yellow fall color. |
| Acer tataricum Tatarian maple |
20 x 20
|
M
|
Single or multi-stemmed tree. Pink to red winged seeds in summer with yellow fall color. Tolerates alkaline soils. ‘Hot Wings’ is a newer variety with distinctive red fruits and reddish fall color. |
| Crataegus ambigua Russian hawthorn |
20 x 15
|
M
|
Lightly thorned tree with finely cut, glossy green leaves. Clusters of white flowers followed by bright red fruits. |
| Crataegus crus-galli inermis Thornless cockspur hawthorn |
15 x 15
|
M
|
Thornless horizontal branches bear glossy leaves, white flowers and persistent red fruit. |
| Pinus edulis, Pinyon pine |
25 x 15
|
S-M
|
Native, bushy evergreen with gray-green, stiff needles. Bares small, rounded cones with edible seeds. |
| Prunus armeniaca Apricot |
20 x 20
|
M
|
Glossy, heart-shaped leaves cover a broad, spreading tree. Early, white-pink blossoms, rarely bares fruit due to spring frosts. |
| Pyrus ussuriensis Ussurian pear |
25 x 20
|
M
|
White flower clusters produced before dark green leaves that turn yellow in fall. ‘Prairie Gem’ is a dense tree with an upright, oval form and strong branching. |
| Quercus gambelii Gambel oak |
20 x 12
|
M
|
Native large shrub or small tree with irregular spreading branches dark green leaves and tan acorns. |
| Table 3. Evergreen xeriscape trees. | |||
| Plant name | Height Spread (ft) |
Growth Rate | Comments |
| Cupressus arizonica Arizona Cypress |
60 x 30 | M | Cone shaped evergreen tree with grayish to bluish green scale-like foliage, does well in the Grand Junction area. |
| Juniperus monosperma One Seeded Juniper |
30 x 30 | S | Native shrubby evergreen with dark blue to purple or brown berry-like cones, and dark green scalelike foliage. Culturally significant. Grows at 5,000-7,000’ elevation. |
| Juniperus scopulorum Rocky Mountain Juniper |
30 x 15 | S | Native evergreen with blue-green foliage. Berry-like cones that are dark blue in the second year. Prefers full sun. Many varieties. Sea level to 9000’ elevation. |
| Juniperus utahensis Utah Juniper |
25 x 25 | S | Native short evergreen tree that is very long lived. Juvenile foliage is needle-like. This tree has a large taproot and doesn’t produce seed till about 30 years old. Elevations of 3,000-8,000’. |
| Pinus aristata Bristlecone pine |
35 x 20 | S | Native evergreen with dark pine green needles bearing white flecks, arranged around the branches. Grows in elevations up to 11,700’ (tree line). |
| Pinus edulis Pinyon pine |
25 x 15 | S-M | Native, bushy evergreen with gray-green, stiff needles. Bears small, rounded cones with edible seeds. 4,500-8,000’ elevation. |
| Pinus ponderosa Ponderosa Pine |
60 x 30 | M | Native evergreen with long, yellow-green needles in clusters of two or three. Plate-like bark is cinnamon to dark brown. Grows sea level to about 9,000’ elevation. |
| Table 4: Shrubs for xeriscapes. | |||
| Plant name | Height Spread (ft) |
Flower color/month
|
Comments |
| Amorpha canescens Leadplant |
3 x 4
|
Purple/Jul – Aug
|
Silver-gray foliage, fine texture, fruit not important |
| Artemisia cana Silver artemesia |
5 x 3
|
Yellow/Aug-Sept
|
Stiff, upright branches, slender gray leaves, native of Colorado mountain meadows |
| Artemisia tridentata Big sage |
10 x 6
|
Yellow/Aug-Sept
|
Silver, aromatic foliage; bark shreds with age, native |
| Atriplex canescens Saltbush |
5x 4
|
Yellow/Jul-Aug
|
Gray green leaves, upright spreading form, four winged fruit on female plants, tolerates alkaline soil |
| Berberis thunbergii Japanese barberry |
3 x 5
|
Yellow-Apr-May
|
Dwarf and purple leafed forms available, site in good light, single spines, red persistent fruit |
| Berberis x ‘Tara’ Emerald Carousel ™ Emerald Carousel barberry |
4 x 5
|
Yellow-Apr-May
|
Rounded form, arching branches, prefers sun, red persistent fruit, orange to red fall foliage color appears early and lasts long, good for alkaline soils |
| Buddleia alternifolia ‘Argentea’ – SilverFountain butterflybush |
10 x 8
|
Violet/May-Jun
|
Arching form, silver-gray foliage, fine texture, flowers on old wood, attracts butterflies, extremely hardy |
| Caragana arborescens Siberian peashrub |
12 x 10
|
Yellow/May – Jun
|
Upright, olive-green branches, bears small spines, produces pea–like pods, tolerant of poor soils and windy sites |
| Caryopteris x clandonensis Blue mist spirea |
4 x 4
|
Blue-violet to purple /Jul-Sep
|
Silver green foliage, upright branches, persistent dry tan fruit, attracts bees |
| Cercocarpus ledifolius- Curlleaf mountain-mahogany |
20 x 12
|
Cream yellow/Apr-May, not showy |
Large shrub or small upright tree, evergreen foliage, seeds with twisted, feathery tails; foothills native |
| Cercocarpus montanus Mountain-mahogany |
8 x 6
|
Cream yellow/Apr-May, not showy
|
Large shrub or small upright tree, evergreen foliage, seeds |
| Chamaebatiaria millefolium Fernbush |
5 x 6
|
White/Jun-Jul
|
Fern-like gray green leaves, fine-textured and aromatic, rounded form |
| Chrysothamnus spp. Rabbitbrush |
6 x 6
|
Yellow/Aug – Sep
|
Open, rounded form, green to white stems, silvery green leaves, reseeds |
| Cowania mexicana Cliff rose |
6 x 6
|
Creamy White/Apr-May
|
Upright semi-evergreen shrub, gray-green leaves, feathery seed tails |
| Elaeagnus umbellata Autumn-olive |
15 x 15
|
Silvery flowers/Apr-May
|
Large spreading shrub, green leaves with silvery undersides, May may sucker and spread |
| Ephedra equisetina Bluestem jointfir |
4 x 5
|
Not important
|
Upright leafless stems are blue-green year round, red berries midsummer on female plants |
| Fallugia paradoxa Apache plume |
5 x 5
|
White/May – Aug
|
Small leaves, fine-textured, whitish stems, rose-colored feathery-tailed seeds, some suckering |
| Fendlera rupicola Cliff fendlerbush |
5 x 5
|
White/Jun
|
Glossy foliage, new reddish bark turns gray with age, upright irregular growth, fragrant flowers |
| Forestiera neomexicana New Mexican privet |
12 x 10
|
Yellow/Apr
|
Erect arching branches, rounded form, blue-black fruit on female, yellow fall color |
| Hippophae rhamnoides Sea-buckthorn |
18 x 12
|
Yellow/Mar-Apr
|
Upright, spreading shrub with slender thorns, narrow silvery leaves, orange fruit on females persists into winter |
| Holodiscus dumosus Rock spirea |
4 x 4
|
White/May – Jun
|
Upright spreading habit, fine-textured foliage turns red in fall, rust colored seedheads in fall |
| Juniperus spp. Juniper |
Many sizes
|
Not important
|
Available in many foliage colors, forms and textures, see Evergreen Shrubs fact sheet 7.414. |
| Ligustrum vulgare ‘Cheyenne’ , Cheyenne privet |
10 x 6
|
White/Jun-Jul
|
Upright, rapid grower, dark green foliage, black fruit in late summer into winter, used for hedges, fragrant flowers |
| Pinus mugo Mugo pine |
Many sizes
|
Not important
|
Many forms and growth habts, see Evergreen shrubs fact sheet 7.414 |
| Potentilla fruticosa Cinquefoil (potentilla) |
4 x 4
|
Yellow/White/PinkJun- frost
|
Compact, speading and upright forms, varied foliage color, full sun for best flowering |
| Prunus besseyi Sand cherry |
6 x 6
|
White/Apr – May
|
Upright rounded form, gray green leaves, purplish black fruit, red fall color |
| Rhus glabra cismontana Smooth sumac |
6 x 6
|
Yellow/Jun – Jul
|
Rounded, suckering shrub, red fall color, fuzzy maroon persistent fruit |
| Rhus trilobata Threeleaf sumac |
6 x 6
|
Yellow, May
|
Dense rounded shrub, three-lobed leaves turn orange to red in fall, some red fruit |
| Rubus deliciosus Boulder raspberry |
6 x 6
|
White/May-Jun
|
Slender arching branches form vase-shaped habit, small purple fruit in late summer |
| Shepherdia argentea Silver buffaloberry |
15 x 12
|
Yellow/Apr-May
|
Dense spreading branches with spines, silvery-green leaves, yellow to orange-red berries on female plants |
| Symphoricarpos albus Snowberry |
4 x 4
|
White/Jun
|
Arching, spreading habit with blue-green foliage, white blue-green foliage, white berries persist, suckers |
| Symphoricarpos x chenaultii ‘Hancock’ Hancock coralberry |
3 x 6
|
Pink/Jun
|
Spreading growth habit with blue-green fine textured foliage, red berries persist. excellent ground cover |
| Syringa vulgaris Common lilac |
15 x 12
|
Purple/Apr – May
|
Upright vase-shaped form, heart-shaped blue-green leaves |
| Viburnum lantana Wayfaring tree viburnum |
12 x 10
|
White/May
|
Broad rounded form, dark green, leathery foliage with deep set veins, crimson fruit turns black in fall, burgundy red fall color |
1J.E. Klett, Colorado State University Extension landscape horticulturist and professor, department of horticulture and landscape architecture; C. R. Wilson, Extension horticulture agent, Denver County. Revised from original fact sheet authored by J.R. Feucht. Revised from original fact sheet authored by J.R. Feucht. Updated by S.Carter, horticulture Extension agent, Tri-River Area. 10/99. Reviewed 12/16.
Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.
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