Pronounciation: FRAX-in-us ox-ee-CAR-pa RAY-wood

Hardiness zones
Sunset 3-9, 14-24
USDA 5-11

Landscape Use: This is a deciduous shade tree that is relatively diminutive in width compared with other Phoenix ash trees. It's a good residential tree for mesic (much greenery) designed yardscapes. Because of its heat sensitivities, Raywood ash is definitely not a good street tree or mall parking lot tree around asphalt and concrete in Phoenix; though in other higher elevation Arizona landscapes these landscape uses are possible. In sum, it is a good lawn tree.

Form & Character: Upright and oblong canopy, tight, formal, regal.

Growth Habit: Deciduous, woody, broadleaf perennial tree, slow to moderate growth to 30- to 40-feet (can reach 80 feet) tall. This tree's form is especially narrow and upright when young with upright extending branches. With age, it becomes somewhat more spreading.

Foliage/Texture: Leaves of ash are oppositely arranged, but are sometimes whorled at the ends of branches, pinnately compound, seven to nine narrow, lanceolate leaflets, each 2- to 4-inches long, clean-looking, dark green, good fall color (rich red-purple), trunk mostly smooth and light gray especially when young; medium fine texture.

Flowers & Fruits: Mostly sterile

Seasonal color: Strong burgundy fall color, mostly in December in Phoenix.

Temperature: In Phoenix, cold hardy, but VERY sensitive to trunk sunscald. Avoid direct and reflected sunlight and radiant energy off of west-facing buildings, as well as concrete and asphalt surfaces.

Light: Full sun to partial shade

Soil: Tolerant

Watering: Regular, a mesic tree.

Pruning: Raise the crown base as needed, but do so conservatively, especially in areas with reflected heat and western sunlight. Young trees generally do not need staking.

Propagation: Grafted

Disease and Pests: Highly susceptible to ash decline (Spiroplasma), also to a lessor extent, scale and aphids.

Additional comments: The reality is that Raywood ash is a good 'urban' tree for most Arizona cities and towns between the elevations of 2,500 and 7,000 feet; Arizona cities and towns such as Prescott, Benson, Safford, Payson, Cottonwood and even Flagstaff. In Phoenix, Raywood ash is very susceptible to trunk sunscald which can easily kill young trees if their trunks are not painted white with a dilute latex paint. Even though its form is conducive to aerial restricted urban spaces, do not plant this upright tree in Phoenix as a street tree or around large expanses of concrete or asphalt that are in full sun exposures. It is a good small tree for urban canyons or in areas surrounded by greenspaces. In general, Fraxinus oxycarpa works better in lawns than other Fraxinus species because of the narrow width of its upright canopy.

Taxonomic tidbits: The cultivar 'Raywood' was selected in Australia in about 1910, and arrived in the British nursery trade by 1928. It was not introduced into North America until about 1956, and not in large scale commerce until about 1980. Other cultivated selections of Fraxinus oxycarpa include 'Flame' and 'Dr. Pirone'. They are very similar, if not identical. The specific epithet oxycarpa means "with pointed fruits".