Landscaping with native and drought tolerant plants like pinon, juniper, aspen, and serviceberry will aid in water conservation and erosion control of slopes.
Growing conditions in the American Southwest are difficult at best. Rainfall averages about 15" a year. Soils are clay and alkaline. Often there is an expansive layer of caliche, a solid rock, just below the surface. The wind blows hard almost constantly, and the sun is hot and strong.
For these reasons, it is easiest, for landscaping purposes, to grow native plants or others that are suitable for this harsh environment. All plants need water and protection when newly planted, but once they are established, they will tolerate poor desert conditions. All should, however, be watered deeply in a severe drought, even in winter. Of course, the more supplemental water they receive, the more they will grow. That is true of all the plants in this list.
Herewith are five trees and shrubs that are suited to southwest desert conditions.
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Pinon - Pinus edulis
This is a slow-growing evergreen tree that will eventually get to 30'. Its deep roots make it drought-tolerant. It also is wind-resistant and heat/cold tolerant. Planted with other shrubs and trees, it is an effective screen and windbreak. It naturally occurs in pinon/juniper forests. In the yard its bushy twisted shaped makes it a beautiful accent plant with wildflowers. The seeds are prized by humans and wildlife alike.
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One Seed Juniper - Juniperus monosperma
This is another evergreen growing to 20'. It too is a slow grower with an irregular shape and a deep root system. It is more tolerant of drought and alkaline soils than the Rocky Mountain Juniper. It grows well on slopes, making it effective for erosion control. It provides food (blue berries) and shelter for wildlife. Plant with other shrubs and pinon as a windbreak, or underplant with wildflowers as an accent plant.
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Aspen - Populus tremuloides
This is a deciduous tree that grows to 40'. It's very graceful, as it moves in the slightest breeze, giving it the name "Quaking Aspen". Aspens do better with supplemental watering, although they will tolerate poor conditions. They do need a cold winter, and do best planted on the north side of the house. Plant in groves, for erosion control, or as a wind break mixed with pines and juniper. As an accent plant, aspens go well with perennials or wildflowers. They are famous for their golden fall color throughout the Rocky Mountains.
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Serviceberry or Shadbush - Amelanchier alnifolia
This is a deciduous shrub/tree that grows to 20'. There are beautiful white flowers in early spring, followed by blue berries in late summer that birds love. You can also make jelly from them. This can be pruned to a tree shape, or left to grow wild and sucker into a thicket. This makes a good screen, although it can be planted with junipers and pinons for the same purpose. As an accent plant, it can be attractively combined with perennials. Serviceberry needs a little shade in the southwest - another good plant for the north side of the house.
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Apache Plume - Fallugia paradox
This is a deciduous shrub that grows to 7'. It occurs naturally on steep slopes along roadsides, controlling erosion. It is extremely drought tolerant. It has white flowers all summer and into fall, which are followed by feathery seed heads (plumes) that glow when backlit by the morning or evening sun. In the yard it needs full sun, and can be pruned for shape. It attracts birds for shelter and food.
