Tuesday, October 30, 2012

The uncommon ornamental hawthorn

Over the last two fall seasons I have been inspired by the subtle color of Thornless Cockspur Hawthorn, Crataegus crus-galli var. inermis to investigate the entire hawthorn family.


The Thornless Cockspur Hawthorn is a small tree 15’ to 20’. The dark green glossy foliage, borne along layered branching becomes a rounded and spreading crown.  The red haws, fruit, grow in abundant clusters accenting the yellow to brown fall foliage which drops to show a twiggy winter appearance.

The species can be either a large bush or small tree. Crataegus crus-galli  has numerous long thorns. In late spring white musky scented flowers appear in trusses of 5-30 flowers.  Native to eastern North America, it is hardy from USDA zones 4-7.

Hawthorn has been used in herbal teas, candies, jams and wine. The wood is extremely hard and creates a hot fire. In Europe thorny hawthorns have been used as pastoral hedges to confine livestock and provide windbreak.

Trees can be easily cultivated in good, well-drained soils they can tolerate periodic wet feet and need extra water in droughty conditions to prevent defoliation. Hawthorns are tough trees of great ornamental value.

Unfortunately hawthorns are susceptible to a number of pests and diseases. Cedar-hawthorn rust and apple fireblight are significant problems.  Left untreated these can damage a tree.

Folklore surrounding hawthorn is extensive, in some parts of Europe the flowers are unlucky, due to  connection with the crown of thorns worn by Jesus. In southern Europe hawthorn is known as May Flower or Mary’s Flower and therefore cherished.

There are roughly 200 species of hawthorn shrubs and trees found throughout northern temperate regions. 150 species are found in the United States, 12 are found native to Minnesota. As a boy I remember running into a thicket of Crataegus macrosperma, Eastern hawthorn, a very unpleasant prickly experience. These native trees have vast potential for breeding superior new varieties. My boyhood experience shows that a number of problems can be resolved, thorniness and suckering are two! Fruits could be improved for commercial production. Ornamental qualities of foliage, flower and fruit color beckon for attention from young horticulturalists.