Trees are often planted as a reminiscence of childhood, a memory from a vacation or a reminder of people once known. However meaningful, if grown in unsuitable environments, trees will have weak growth and short lives.
Fortunately, some trees (and shrubs and other plants) have proven themselves as outstanding stars in our local landscapes. They are known as Oklahoma Proven and are selected annually by a group of local expert horticulturists in the Department of Horticulture and Landscape Architecture at Oklahoma State University.
One of our best native oaks, the Shumard Oak (Quercus shumardii) stretches 40-60 feet tall at a moderate growth rate of 12-24 inches per year and spreads an umbrella of shade 30-40 feet wide. Pyramidal in its youth, it matures to a broad, open crown. Acorns are not produced until the tree is 25 years old. In autumn, the 6-inch deeply lobed, shiny green leaves turn a quiet red.
Have a smaller yard?
For a smaller yard, the Chinese Pistache (Pistacia chinensis) provides not only shade in summer, but a burst of yellow-orange-red in the fall. At a moderate growth rate of 12-24 inches per year, it matures at 30-35 feet tall with a spread of 20-30 feet. Awkward and gangly in its early years, it matures to a full, rounded canopy. Female trees produce red-ripening-to-blue fruit, inedible for humans but devoured by birds. Deep rooted and drought tolerant, Pistache is often used in xeriscaping, a method of gardening that removes or reduces the need for irrigation.
With its aromatic, soft, scale-like needles, the silvery blue Arizona Cypress (Cupressus arizonica) provides an alternative coloring for the landscape. Growing at a moderate 12-24 inches per year, it can grow 40-50 feet tall and 15-20 feet wide and is drought tolerant once established. It is beautiful planted alone or grouped as a hedge or screen.
Need a smaller patio tree?
Perfect for patios, the Desert Willow (Chilopsis linearis) reaches 15-30 feet tall with a 10-25 foot spread. Violet scented, white to pink, funnel-shaped flowers are a hummingbird favorite in early summer, with blooms erupting periodically into autumn. Winter shows off the twisting branching structure. Drought tolerant, it can be used in the xeric garden.
Tried and true?
And, you can never, ever go wrong with the Oklahoma Redbud (Cercis canadensis var. texensis). Discovered in the Arbuckle Mountains, “Oklahoma” explodes with deep magenta flowers that cover the branches in spring, followed by glossy, heart-shaped leaves. At 15-25 feet in height, this can be a perfect addition to any landscape.
For a full selection of Oklahoma Proven trees, visit oklahomaproven.org/plant-profiles-by-category/trees.