Hawthorns are more or less thorny rosaceous plants with white or pink colored flowers. It is the decorative shapes which makes them particularly popular as garden shrubs.
Origin and Appearance
The botanical name for the Hawthorn (Crataegus) is derived from the Greek word ‘krataigos’ and means ‘strength’. It relates to the extremely tough, hard wood of the various species. There are around 90 different hawthorns in Europe and Asia, and up to 1000 in North America. However, the summer green shrubs, which are a member of the rosaceous plant family (Rosaceae), are a complicated case for botanists, as many species cannot be clearly differentiated from one another.
There are five further common species and hybrids. They all form medium-sized, 16 to 23 feet high bushes or trees, with wide, round, often expansive crowns and thick, loose branching. The gray-green to reddish-brown branches are thorny, to varying extents. The Red Haw has the fewest, the North American cockspur hawthorn (Crataegus crus-galli) has the most and the longest. The leaves are small, ovate to elongated oval or slightly to heavily lobed. Some species have a luminous yellow to carmine red fall foliage. The usually white to pale pink colored flowers form on perennial wood. They open in May and June in full bloom and appear on flat panicles in most species. The small, red star fruit is edible but tastes somewhat bland. It can be made into a jam or wild-fruit marmalade. The most decorative is the large, orange-red fruit of the Hybrid Dockspur Thorn (Crataegus x lavallei ‘Carrierei’), a hybrid which was developed in France around 1870. The usually don’t drop until the winter months.
The common Hawthorn is not only a wild fruit but also an important healing plant. Its contents have a vasodilative effect, which is why Hawthorn preparations are frequently used in natural medicine to treat heart failure. It is also one of the most valuable bushes for its native wildlife: Bees and other insects love to visit the nectar-rich flowers. The dense, thorny crown provides a safe breeding place for many species of bird and the fruit is an important source of nutrition in the winter. The rare red-backed shrike also loves to use the thorns of the hawthorn to pierce captured insects and small vertebrates.
The tree-like Hawthorn - in particular the Red Haw and the Hybrid Cockspur Thorn - are popular solitary trees for home gardens and public greenery. A highly popular combination which can often be seen in old farm gardens is red haw and laburnum, as the two bushes flower at the same time. It’s deep reaching, only slightly branched surface roots, mean the Hawthorn can be readily under-planted with shrubs and and smaller bushes. The native wild species are important bushes for bird protecting hedges and more than a must for many gardens, not only near-natural ones. They are ideal for free-growing hedges and other bush plants in untamed nature. They can also be used as trimmed hedges - their long thorns can reliably keep the neighbor’s cats out of your own garden. Thanks to their picturesque, gnarled growth and bark, which becomes ridged with age in a visually appealing manner, all species of hawthorn are also well suited for Bonsai cultivation.
They can be thinned occasionally, although this is not essential. The bushes do not age and become more beautiful year on year without pruning. This robust bush copes with any heavy cutting back required without any problems.
The wild Hawthorn species can be propagated through seed sowing, however, only the common Hawthorn germinates quickly and reliably. The seeds from other species sometimes only take after three years. The hybrid varieties are generally propagated through budding on seedlings of the Common Hawthorn. Other grafting methods, such as splice grafting in late winter, are also possible. Hardwood cutting propagation of red haw and hybrid cockspur hawthorn is worth a try, although in most cases it delivers very poor growth results.
Diseases and Pests
The most common fungal diseases are rust and leaf spot diseases. Powdery mildew can also occasionally occur. Unfortunately, the various species are also susceptible to fire blight, a bacterial infection which must be reported. Infected plants can be identified by the dead and black-brown colored shoot tips which appear burnt. Affected plants should be immediately removed and burned. Pests such as Gall mites, Psyllids, Aphids and Ermine Moths cause non-fatal damage to the plants.