Introduction
This fast-growing, deciduous, native North American tree reaches a height of 30 to 50 feet, depending upon cultural conditions. It is capable of growing taller in its native habitat. The three to six-inch-long leaves are divided into multiple leaflets and turn a brilliant yellow in fall before dropping. The inconspicuous, green, springtime flowers are followed by the production of showy, persistent fruits. The tree has been widely grown in California and in parts of the west including Texas.
General Information
Scientific name: Fraxinus velutina
Pronunciation: FRACK-sih-nus vell-LOO-tih-nuh
Common name(s): Velvet Ash, Modesto Ash, Arizona Ash
Family: Oleaceae
USDA hardiness zones: 7A through 8B (Fig. 2)
Origin: native to North America
Invasive potential: little invasive potential
Uses: reclamation; urban tolerant; shade; street without sidewalk; parking lot island 100-200 sq ft; parking lot island > 200 sq ft; tree lawn > 6 ft wide; tree lawn 4-6 feet wide; sidewalk cutout (tree pit); highway median
Availability: not native to North America
Description
Height: 30 to 50 feet
Spread: 45 to 60 feet
Crown uniformity: irregular
Crown shape: round
Crown density: moderate
Growth rate: fast
Texture: medium
Foliage
Leaf arrangement: opposite/subopposite (Fig. 3)
Leaf type: odd-pinnately compound
Leaf margin: serrate
Leaf shape: lanceolate, elliptic (oval)
Leaf venation: pinnate
Leaf type and persistence: deciduous
Leaf blade length: less than 2 inches, 2 to 4 inches
Leaf color: green
Fall color: yellow
Fall characteristic: showy
Flower
Flower color: green
Flower characteristics: not showy
Fruit
Fruit shape: elongated
Fruit length: .5 to 1 inch
Fruit covering: dry or hard
Fruit color: green, tan
Fruit characteristics: does not attract wildlife; showy; fruit/leaves a litter problem
Trunk and Branches
Trunk/bark/branches: branches don't droop; not showy; typically one trunk; thorns
Pruning requirement: needed for strong structure
Breakage: susceptible to breakage
Current year twig color: gray
Current year twig thickness: medium, thick
Wood specific gravity: unknown
Culture
Light requirement: full sun
Soil tolerances: clay; sand; loam; alkaline; acidic; occasionally wet; well-drained
Drought tolerance: high
Aerosol salt tolerance: unknown
Other
Roots: not a problem
Winter interest: no
Outstanding tree: no
Ozone sensitivity: tolerant
Verticillium wilt susceptibility: susceptible
Pest resistance: sensitive to pests/diseases
Use and Management
The tree has been traditionally difficult to maintain due to the development of many upright trunks originating from the same position on the main trunk. This condition has lead to the creation of weak trees which often break apart at the base of the multiple trunks. Careful pruning and branch selection is required during the first 15 years after planting to ensure good, strong trunk and branch development. It is important to purchase good quality planting stock which has a central leader and no upright multiple trunks. This will make the tree much easier to maintain in the landscape. Some horticulturists do not recommend planting this tree due to the high pruning requirement and susceptibility to breakage.
Velvet Ash should be grown in full sun on any soil and will tolerate both alkaline and rocky soils. It is tolerant of wet soil and has been extensively used along streets in areas with poor drainage. Roots often grow close to the soil surface causing a nuisance by breaking sidewalks and curbs.
The cultivar `Arizona' is widely planted but reportedly has the same problems as the species.
Propagation is easily done by seed.
Pests
It is very susceptible to borers. Trees often have a short-life.
Diseases
Texas Ash is susceptible to verticillium wilt.