Culture
Grow in moist to wet soils in full sun to part shade. Prefers moist soils, but also tolerates drier upland soils. Best fruit production occurs in full sun. Prune if necessary in late winter. Will sucker to form thickets.
Noteworthy Characteristics
Crataegus douglasii, commonly known as black hawthorn, typically matures over time as a small upright tree to 20-30' tall featuring dense clusters of white flowers in spring, edible fruits that mature to black in late summer and a spreading rounded crown of branches (young twigs red) clad with attractive green leaves and sharp thorns. It also sometimes grows as a much shorter bushy thicket-forming shrub. It is native to wetlands, open moist places, bluffs and slopes, meadows, ditches and along streams in a large geographic territory extending from Alaska to Quebec south to Michigan, South Dakota, Nevada and California, but within such territory is most commonly found in the Pacific Northwest. Fragrant, five-petaled, white flowers (to 1/2" diameter) with cup-shaped bases bloom in flat-topped clusters (10-12 flowered corymbs) rising from the leaf axils and branch ends in mid to late spring (May-early June). Flowers have an unpleasant fragrance which tends to attract pollinators such as midges and butterflies. Flowers are followed by abundant, globular, red fruits (to 1/2" diameter) which ripen to black in late summer. Fruits are edible and commonly called haws. Fruits usually drop to the ground in late fall, but may persist on the tree in a shriveled raisin-like form. Shiny, sometimes mildly lobed, leathery, ovate to obovate leaves (to 3-5" long) with saw-toothed margins (primarily above the leaf midpoint) are dark green above and pale green underneath. Fall color is usually insignificant, but sometimes surprises with showy tones of red, orange and yellow. Branches are armed with stout spines to 1" long. Rough scaly gray bark develops on older trees.
Genus name comes from the Greek name for the tree. From kratos meaning strength for its strong, hard wood.
Specific epithet is in reference to Scottish botanist David Douglas (1798-1834) who discovered this plant in his North American explorations (Douglas fir is also named after him).
The name hawthorn comes from an Anglo-Saxon word haguthorn which means fence with thorns.
Crataegus is a large genus containing over 200 species.
Problems
Cedar-hawthorn rust, cedar-quince rust, fireblight, fungal leaf spots, powdery mildew, cankers and apple scab are occasional problems. Insect pests include borers, caterpillars, lacebugs, leafminers and scale. Falling fruit can create clean-up problems in fall.
Uses
Attractive flowers, foliage and fruit. Small flowering landscape tree for lawns or streets. Native plant areas. Specimen, small groups or screen. May be pruned as a hedge. Hedgerows. Erosion control.