Fraxinus quadrangulata Michx.
Oleaceae (Olive Family)
USDA Symbol: FRQU
Blue ash grows 50-70 ft. in height and develops a slender, straight, slightly tapered trunk which supports a narrow, rounded, crown of spreading branches. Young twigs have four winged, corky ridges running lengthwise along the bark. The deciduous foliage is similar to other ashes, turning yellow in fall. The bark is different than other ashes, having a scaly appearance.
The name, quadrangulata, means 4-angled and refers to the 4 corky ridges on the twigs. This characteristic distinguishes blue ash from all other ashes. Another unique feature is the sticky sap from the inner bark, which turns blue when exposed to air
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Plant CharacteristicsDuration: Perennial
Autumn Foliage: yes
Size Class: 72-100 ft.
Bloom InformationBloom Color: Green , Purple , Brown
Bloom Time: Apr
DistributionUSA: AL , AR , GA , IA , IL , IN , KS , KY , MI , MN , MO , MS , OH , OK , TN , VA , WI , WV
Native Distribution: Extreme s. Ont., MI & WI, s. to GA, n. AR & extreme s.e. KS
Native Habitat: Lowland wet to upland dry, open woods
Growing ConditionsLight Requirement: Sun , Part Shade
Soil Moisture: Moist , Wet
Soil pH: Circumneutral (pH 6.8-7.2)
Soil Description: Variable.
Conditions Comments: Blue ash is fast-growing yet long-lived. It is tolerant of various climates and soils, and is unique among the ashes for its tolerance of drought and alkalinity. The inner bark of the tree reveals blue coloring when mixed with water, giving reason for the common name. Susceptible, like many ashes, to a wide variety of disease and insect pests; these usually are not a problem to vigorously growing trees.
PropagationDescription: Seeds may be sown outdoors after collection or stored and stratified then sown in spring.
Seed Treatment: Stratify in moist sand or perlite for 30-60 days at 41 degrees.
Commercially Avail: yes
Additional resourcesUSDA: Find Fraxinus quadrangulata in USDA Plants
FNA: Find Fraxinus quadrangulata in the Flora of North America (if available)
Google: Search Google for Fraxinus quadrangulata
MetadataRecord Modified: 2012-07-31
Research By: TWC Staff