Attractive in all seasons (pictured here in autumn), the green hawthorn cultivar 'Winter King' is a handsome small tree often planted in both home and commercial landscapes.
Green hawthorn, Crataegus viridis, is a North American native tree that is rarely found in cultivation except as the selection, 'Winter King'. The wild species is a thicket forming hawthorn and, unusual for the mayhaw genus, almost thornless. Rarely reaching as much as 40 ft (12 m) in height, green hawthorn has a rounded shape with a dense crown of foliage on horizontally spreading branches. The trunk, up to 18 in (45 cm) in diameter, is often fluted, and the bark is pale gray and scaly. The elliptical to oval leaves are shiny dark green to yellowish green, up to 2.5 in (6.25 cm) long and half as wide. They are broadest above the middle and finely saw toothed on the edges. The flowers have five white petals and numerous yellow anthers, and measure about 5/8 inch (15 mm) across. Ten to twenty are borne in branching clusters (corymbs) on long slender stalks, the corymbs about 2 in (5 cm) across. The fruit is a pome, like a tiny apple, almost a half inch (12 mm) across, and can be bright red, orange or yellow, varying tree to tree. The fruits ripen in autumn and often persist on the tree into winter.
Crataegus viridis 'Winter King' was introduced in 1955 by Simpson Nursery in Indiana. It has become a very popular landscape small tree. 'Winter King' differs little from the species as described above, except that the fruits are always bright red and also a little larger, about 0.5 in (12.5 mm) in diameter. The leaves reliably turn red in autumn.
The wild Crataegus viridis occurs naturally on wet sites along streams and valleys on the southeastern Coastal Plain from Delaware, southward and across northern Florida to East Texas, and up the Mississippi valley as far as southern Indiana.
Culture Light: Green hawthorn will grow in full sun to part shade. Moisture: The hawthorns are typically trees of moist sites, and green hawthorn does best in moisture retentive (but not waterlogged) soils. Once established green hawthorn 'Winter King' is surprisingly drought tolerant. Hardiness: USDA Zones 5-8. Propagation: Seeds of the species may take 18 to 24 months to germinate. The cultivar, 'Winter King' is propagated by bud grafting, but young fast growing stem tips taken in spring can be rooted, especially under mist.
'Winter King' hawthorn blooms in spring just as the leaves are appearing.
'Winter King' hawthorn fruits are called pomes as are apples which they resemble in minature.
Green hawthorn 'Winter King', is tolerant of urban pollution, and commonly used as a specimen shrub in small landscapes and as a street or parking lot tree. With its a dense crown, it also is useful in hedges and as a screen. The profusion of springtime flowers is lovely, and the bright red clusters of fall and winter fruits are extremely showy. The silvery gray bark peels off in strips, revealing a cinnamon-orange inner bark. Few deciduous trees are as showy in winter as Crataegus viridis 'Winter King''. For the best winter show, plant 'Winter King' in front of evergreen conifers. The leaves of green hawthorn turn shades of yellow and red in most autumns before dropping.
Green hawthorn flowers are attractive to bees and other insects and the fruits are eventually eaten by wintering birds and small mammals. Although technically edible, the fruits are rather tasteless and no doubt worth more to the birds than to people.
Hawthorns can be susceptible to cedar-hawthorn rust if eastern red cedars (Juniperus virginiana) are growing in the area. Fast growing specimens may also be attacked by the fire blight fungus.
The hawthorn or mayhaw genus contains over 200 species according to some authorities; fewer than 100 according to others. All are small, deciduous trees or shrubs, usually bearing thorns. The genus occurs throughout the Northern Hemisphere.