Washington Hawthorn

(Rosaceae - Rose Family)

Form

• small ornamental tree
• maturing at about 20' tall by 20' wide
• upright oval growth habit in youth, quickly becoming spreading rounded to arching mounded with age; often multi-trunked, densely branched, and twiggy with numerous thorns
• slow to medium growth rate

Culture

• full sun to partial sun
• prefers moist, well-drained soils in full sun, but is tolerant of poor soils, various soil pHs, compacted soils, drought, heat, and Winter salt spray
• propagated by seeds and rooted cuttings
• Rose Family, with several diseases and pests, most notably various rusts that affect the stems, foliage, and fruit (especially the extremely common cedar hawthorn rust and cedar quince rust, which will lead to a steady decline in tree vigor as they re-occur year after year)
• abundantly available in clump (multi-trunk) or tree (single trunk) forms, primarily in ball and burlap form
• Washington Hawthorn is somewhat sensitive to being transplanted in Autumn, and care should be taken to amend the soil, fertilize, water thoroughly, mulch adequately, and avoid Winter salt spray, to enhance survival chances during the first Winter

Foliage

• emerging reddish, but quickly maturing to dark green and shiny on the upper leaf surface, while dull medium green on the lower leaf surface
• alternate, broadly ovate, about 2" long, with three major lobes, with the terminal lobe being much larger than the basal two lobes
• doubly serrated to incised on the margins, with cordate bases
• fall color is burgandy to wine, occurring in late October and into mid November, and subtlely attractive

Flowers

• white inflorescences (about 2" wide) blanket the tree in early June (it is the last of the landscape Hawthorns to flower), effective for two weeks and extremely malodorous

Fruits

• 0.25" diameter green fruits are in pendulous clusters, turning to orange by October then to bright red-orange in November, and often persisting into late January (if not eaten by wildlife before then)
• clusters of many pendulous small red fruits make this one of the most attractive ornamental trees in early Winter, with its limbs being blanketed and weighted down in fruits and easily seen from a distance in December and January
• fruits are readily eaten by birds and squirrels
• infections of various rusts create white-orange protuberances on the green fruits in Summer (especially following wet Springs), usually causing these infected fruits to abscise before Autumn

Twigs

• thin twigs with small buds are red-brown and somewhat zig-zag, changing to reddish-gray on the stems and branches
• the thorniness of the twigs shows great variation within the species, from lightly thorny to densely thornly; in either case, this tree is a literal pain to prune and handle, as its sharp thorns eventually penetrate gloved hands and shirted forearms
• very twiggy in appearance, and shedding small twigs continuously from self-shading in the interior of the dense canopy

Trunk

• usually either multi-trunked or single-trunked and branching low, but sometimes single-trunked and limbed up into classic tree form
• bark exfoliates into thin strips to reveal a red-orange interior bark beneath a brown-gray exterior bark
• branches, although composed of dense and strong wood, are sometimes prone to storm damage with age, a combination of the heavy fruit loads in Autumn/Winter (or ice loads that may occasionally accumulate on the thin but numerous twigs) and narrow crotch angles at some (not all) of the major branch junctures

ID Summary

• leaves emerge bronze but quickly transition to dark green, and have three serrated and incised lobes, with the central lobe being prominently larger than the basal pair
• white inflorescences are the last and smelliest of the landscape Hawthorns to flower, in early June, pungently malodorous and effective for two weeks of nasal torture
• clusters of pendulous green fruits in Summer (which often have pink-orange projections of rust growing on them, especially in the Spring was wet) change to orange-red fruits by mid-Autumn, then to heavy red-orange fruits in late Atumn and early Winter, when they abscisce or are consumed by wildlife
• trunk(s) has bark that exfoliates in thin linear strips, exposing a red-orange interior bark

USAGE

Function

• specimen, focal point, foundation, entranceway, border, street, group planting, or multi-season accent tree

Texture

• medium-fine texture in foliage and fine texture when bare
• thick density in foliage and when bare

Assets

• four-season ornamental tree
• showy late Spring white inflorescences
• showy Autumn red fruits and burgandy fall color
• showy early Winter fruits and bark/twigginess/texture
• urban tolerant
• wildlife attraction and refuge
• Winter salt spray tolerant

Liabilities

• severe rust diseases (including cedar hawthorn rust and cedar quince rust) may infect the fruits, leaves, and stems, and often re-occur from year to year once established
• malodorous inflorescences in late Spring
• thorns on lower branches that are at pedestrian level are a potential injury liability
• rarely prone to trunk splitting or branch shearing with wind or ice, in instances when branch-to-trunk crotch angles are very narrow

Habitat

• zones 3 to 8 (but performs better in the northern half of its range)
• native to the Southern United States

SELECTIONS

Alternates

• ornamental trees with good multiseason appeal (Amelanchier arborea, Cornus kousa, Crataegus viridis 'Winter King', Malus, etc.)
• trees or large shrubs serving as wildlife food sources and refuges (Crataegus crus-galli, Lonicera maackii, Malus sargentii, Viburnum prunifolium, etc.)

Variants

• clump (multi-trunked) and tree (single-trunked) forms of the straight species are commonly available
• Crataegus x 'Vaughnii' - Vaughn Hawthorn - a hybrid between Cockspur Hawthorn (Crataegus crus-galli) and Washington Hawthorn (Crataegus phaenopyrum), more upright and less thorny than either of its parents, with abundant fruits of intermediate size, but of low commercial availability, noted for its salt spray tolerance, and effectively used as a street median or island parking lot tree in addition to the other functions noted above

NOTES

Translation

• Crataegus translates as "strength", referring to its wood strength.
• phaenopyrum translates as "with the appearance of a pear", possibly referring to its pendulous branches when weighted down with ripe fruits, that somewhat resemble the strained appearance of pear tree branches (Pyrus communis) when fully loaded with ripe fruits.
• formerly classified as Crataegus cordata, with the former specific epithet referring to its foliage having cordate bases.

Purpose

• Washington Hawthorn is a four-season ornamental tree, becoming an accent tree in early Winter with its persistent red fruits.

Summary

• Crataegus phaenopyrum is a highly ornamental small tree of rounded to semi-pendulous habit at maturity, with showy but malodorous late Spring inflorescences, dark green Summer foliage, burgandy late Autumn fall color, late Autumn and early Winter red fruits, fine texture, lightly exfoliating bark, and dense twigginess, that also attracts wildlife and often has rust as a severe disease problem with age.