Hawthorn, Black - Crataegus douglasii

(Hawthorn Douglas - Crataegus douglasii var. douglasii)

An erect shrub to small tree up to 10 meters (33 feet) tall; branches are zigzagging stems, armed with stout 1 inch thorns and reddish brown in color aging to dirty gray; leaves are alternate, deciduous, obovate, irregularly toothed and can be 5 to 9 shallowly lobed, dark green to red when growing in full sunlight; flowers in axillary clusters, white; fruit is a small dark reddish purple to black globe-shaped apple in clusters. Habitat is generally in drier locations of riparian zones on clay loam to sandy loam soils at low to mid elevations. Watertable is generally within 40 in of the surface in spring or during high runoff events, but falls below this level later in the growing season. This species is tolerant of poorly drained soils and semi-prolonged flooding. Fruit ripens late-July through August, percent fill varies widely among trees necessitating frequent cutting tests, separate seed by macerating fruit and floating off pulp and empties, spread seed in thin layers to avoid heat build-up; Air dried seed can be stored for 2 to 3 years at 5°C (41°F); Propagation by seed requires pretreatment with acid for 0.5 to 3.0 hours followed by cold stratification at 5°C (41°F) for 84 to 112 days, germination of 50 to 80 percent is common, seed may be fall sown after pretreatment or held in cold storage after scarification until the following spring, sow seeds approximately 0.5 centimeter (0.2 inch) in depth or broadcast sow and cover to a similar depth with soil; transplant from seedbed before the second growing season, fresh seed may be fall sown directly without pretreatment, however, it may be two or more years before germination occurs.

Greenhouse asexual propagation is possible by using suckers or by layering.

Field propagation by dormant unrooted hardwood cuttings is rarely successful.

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Last Modified: 07/05/2007