Prunus cerasifera ‘Krauter Vesuvius’ Purple Leaf Plum
up to 20 ft. high x 15-20 ft. wide
Dark purple foliage with masses of pink spring blooms. These ornamental, non-fruiting trees are deciduous and moderate to fast growing with ample water needed during summer in low deserts. They are medium to small flowering accent trees that typically grow 15 to 20 ft. in Phoenix. This variety has soft, thin oval shaped leaves with a deep burgundy to purple color. If they are shaded by larger trees the foliage takes on a green hue. In spring, trees produce pink to white flowers in masses before the leaves sprout out. They are not particular about soil, although well-drained soil is best. Minimal annual pruning for shape and size is all they require.
Quercus virginiana Western Live Oak
Stately, rugged slow growing evergreen oaks. This is one of the most durable, evergreen shade trees for the southwest with a moderate to slow growth rate. They are extremely heat and cold tolerant for western native trees. To perform well, they require deep, regular waterings in summer to develop healthy roots and canopy. Dark green shiny leaves are elongated oval shape as are the acorns that can form and drop. They are sturdy trees with sturdy upright spreading branches that may require periodic thinning or pruning for shape, otherwise they have few pest or disease problems. Immature trees can look shrubby with low branches and leaves virtually to the ground. With regular moisture during the growing season trees will develop a deep wide growth sustaining root system.
Robina Purple Robe/Black Locust Tree
Durable deciduous tree for low, mid, and high desert landscapes. Lacy, emerald green foliage from upright growing canopies. Woody trees typically grow taller than they are wide with dark fissured bark. Their claim to fame for the landscape is long, drooping violet-purple, sweet-pea-like flowers in spring. ‘Purple Robe’ blooms about 2 weeks longer than other similar selections. Easy to grow with moderate to ample summer water, small branches can be brittle and drop, but are easy to pick up, otherwise wood is hard and dense. Use them as ornamental trees in residential landscapes, commercial sites, municipal streets, parks, or open areas with no overhead obstructions. Cold hardy enough to use anywhere in Arizona.
Sophora secundiflora Texas Mountain Laurel
Striking purple hanging fragrant spring flowers. Large evergreen shrubs to small trees. Sometimes single trunks but most often are multi-trunked. They are slow to moderate growing which means container grown plants are slower to gain size and stature. Once in the ground where roots can grow and develop, they will more quickly gain size. Immature foliage is made up of compound, shiny lime-green leaflets, turning darker green with maturity with white pubescence underneath. In spring drooping purple to violet-blue flowers appear that have a strong fragrance, some say grape soda or sweet cinnamon. Bees and humans alike are attracted to the color and fragrance. Flowers morph into fuzzy white peanut-like pods with reddish seeds which are poisonous that can be discarded when cracked open. In low deserts, they perform best with deep periodic watering, especially during summer. Training is like any other evergreen large shrub, however bloom wood is produced in late summer the year prior, so if plants are trimmed at the wrong time, they will fail to bloom the next spring. The best time to prune is during April & May.
Tipuana tipu Tipu Tree
Lovely, fast growing yellow flowering shade trees. These upright woody trees are fast growing with large, soft compound leaflets. They are evergreen to semi-deciduous in low deserts with mature trees becoming more resistant to cold. They have an attractive size, canopy texture, and provide suitable shade for growing a plethora of understory accent plants or perennials. In late spring to summer trees form clusters of sweet-pea-like flowers of bright yellow at the ends of all the branches, which gives them a delightful golden silhouette. Provide moderate to ample water, especially for immature trees and for all trees during low desert summers. Unfortunately, these trees are not conducive to planting in parking lots or areas with intense reflected heat.
Ulmus parvifolia Evergreen Elm, Chinese Elm
Sturdy, predictable shade tree. Evergreen is a bit of a misnomer for these shade trees, since they are really semi-evergreen to deciduous. They are moderate to fast growers with ample water. They have an upright, naturally dense umbrella shaped canopy with strong, flexible wood. Leaves are oval, shiny green with slight serration and their distinctive exfoliating bark is highly ornamental with rough tan and gray appearance. They make excellent shade trees for use in residential, commercial, or municipal landscapes, as well as street or parking lot trees where they can be planted without overhead interference from powerlines or other obstructions. They produce inconspicuously small green flowers in late spring to summer that set into copious amounts of small papery seed pods that then drop in fall and winter. Years with more cold will cause more leaf color and drop, but in spring new foliage emerges with an amazing bright lime green color. Maintenance required is mostly for leaf and seed pod clean up, along with some selective minimal pruning during dormancy for shape and canopy healthy. They appreciate more water than most desert trees, but are still quite drought and heat tolerant once mature.
Vitex agnus-castus Chaste Tree, Lilac Chaste Tree
Summer welcoming lilac-like flowers. For clients longing for bright cheery lilac blooms like they had in the Midwest or northeast, this is the best option, since they are durable to both heat and drought, unlike true lilacs are. These are large shrubs to small multi-trunked deciduous trees with attractive dark green pointed palmate leaves and long wide spikes of bright blue to lilac colored flowers. These heat-loving plants are often the last plants to leaf out in spring, waiting until the nighttime temperatures are quite warm to do so, but shortly after leafing out, masses of blooms form to cover the plants in spikes of bright blue. They are moderate to fast growing which makes them easy to trim and train into spectacular individual specimens or they can be planted as shrubs with narrow spacing to create a more formal hedge or dense, woody barrier. Adaptable, easy-to-grow with minimal maintenance.