Arizona Ash (© Brandt Magic

Arizona or Velvet Ash (Fraxinus velutina) is a native tree and parent of the widely planted “Modesto” ash cultivar.

Scientific name: Fraxinus velutina

Alternate name: Velvet Ash

Family: Oleaceae, Olive Family

Description: A fast-growing perennial deciduous shade tree native to riparian areas throughout the desert southwest, including the Rio Grande bosque. This is an useful shade tree where summers are long, hot, and dry, and where soils are alkaline. This species, and especially the “Modesto” cultivar (named for the California town from which it was collected) is commonly planted as a shade & street tree in desert areas. This cultivar is considered overplanted in New Mexico, since the abundance of genetically identical trees makes them highly vulnerable to pests. While our Modesto ashes continue to thrive for now, the emerald ash borer has already devastated overplanted ash cultivars in the Eastern United states, and its arrival here would likely kill most of our trees.

Young trees are pyramidal, but the shape becomes more rounded and open as mature height is reached.

Preferred Habitat: Riparian, including the Rio Grande bosque. Widely planted ornamental

Climate-readiness: Tolerates heat and drought, but not recommended due to pest issues and frequent branch breaking.

Leaves: 3-5 narrowly oval leaflets, each about 3 inches long. Foliage turns yellow in autumn. The “velvet” is a gray fuzz that covers the young twigs and leaves of most trees.

Flowers: Generally inconspicuous, blooms in springtime in clusters. Male and female flowers on separate trees. Male flowers drop in the spring in large quantities but quickly decompose.

Fruit: Fruits in the form of samaras that hang in dense clusters, will grow on female only if it is near a male tree. A large quantity are dropped in the fall.

Bark: gray, deeply furrowed into broad, scaly ridges

Elevation: Up to 7000 feet

Frost Tolerance: Hardy to -10° F (-23° C)

Heat Tolerance: Excellent

Sun Exposure: Full sun

Origin: Southwestern USA (Arizona, California, Nevada, New Mexico, Texas, Utah) and Northern Mexico

Growth Habits: 30 feet tall or more

Watering Needs: Moderate water

Pests: The Emerald Ash Borer is an introduced beetle that has devastated ashes throughout eastern North America. Although the Emerald Ash Borer has not yet entered into New Mexico, it is spreading and has been identified just across the Colorado border.