Washington Hawthorn (Crataegus phaenopyrum)

A deciduous tree from the Rose Family (Rosacea)

Washington Hawthorn, the last of the Hawthorns to flower, is found in the wild throughout portions of the eastern and southern United States, but only rarely in the woods and fields of Ohio, concentrated in the extreme mid-eastern and southwestern counties of the state. However, it is extensively planted in urban landscapes as an ornamental tree noted for its white flowers in spring and orange-red fruits in autumn and winter.

Wildlife relish the abundant small fruits, which may hang on the trees into late January if they are not eaten. Washington Hawthorn may reach 20 feet tall by 15 feet wide when found in the open, often with a multitrunked and arching growth habit at maturity. As a member of the Rose Family, it is related to the Serviceberries, Chokeberries, Crabapples, Plums, Cherries, Pears, and Roses, as well as the many other Hawthorn species and hybrids.

Planting Requirements - Washington Hawthorn prefers moist soils of good drainage and variable pH, but is very adaptable to poor, dry, compacted soils. It is found in zones 4 to 8, in full sun to partial sun.

Potential Problems - Washington Hawthorn has a number of pests that feed on its foliage and emergent stems, but none are usually life-threatening and only cause cosmetic damage. It has several pathogens that affect leaf and fruit quality (most notably fruit scab), but there is one disease that is life-threatening over a period of years. Rusts (there are several) infect the new vegetative growth in spring, as well as the green fruits. As the rusts continually infect the same areas year after year, the ability of the tree to send out new growth is diminished, and the tree is weakened and may eventually die if preventative spray measures are not taken.

Leaf Identification Features

Leaves of Washington Hawthorn are alternate, ovate, shallowly five-lobed, doubly serrated, and shiny dark green in summer.

The thin twigs are covered with straight, sharp thorns as well as the leaves. Fall color of the foliage is often burgundy, with shades of yellow, orange, and red, and occurs in mid- to late autumn, in combination with the orange to red-orange fruits.

Other Identification Features

The perfect white flowers of Washington Hawthorn occur in late spring (the last of the Hawthorns to flower) and have a very malodorous scent when they are in full bloom. Green fruits in pendulous clusters soon follow, and in many summers some of the immature fruits are infected with rust.

The common name of these pathogens with white-orange protuberances comes from the release of millions of spores that cover the ground below with a coating of orange "rust".

Fruits transition in early autumn to an orange color, then a bright red-orange from mid- autumn into early winter. By mid-winter, all the fruits are gone, either consumed by wildlife (squirrels and birds especially) or dropping to the ground after many hard freezes.

The mature bark of Washington Hawthorn is flaky, with brown to gray outer plates and flakes that cover a red-orange interior bark. Washington Hawthorn is usually multitrunked, or single-trunked with low branches, and armed with thorns throughout its twiggy, arching canopy of branches.