Midland hawthorn

Identification and origin

Crataegus laevigata belongs to the rose family, Rosaceae, along with apples, pears and mountain ash. It is native to western and central Europe: its range runs from Spain, France, Corsica and Sicily to Great Britain, Denmark, Norway, Sweden, the Baltic States, Belarus, Ukraine and European Russia. It has become naturalized in Ireland and in Washington State.

It is a large, dense, thorny shrub that can grow into a small tree with a rounded crown. In cultivation it reaches 13–26 ft tall and as wide, sometimes more, over twenty to fifty years.

• Leaves: deciduous, dark green and glossy, 1–2 in long, divided into three to five rounded, shallow, finely toothed lobes.
• Thorns: numerous on the branches, 0–1 in long, sometimes absent. In winter they arise at the same point as the buds, which sets hawthorn apart from blackthorn, whose buds sit on the thorns.
• Flowers: creamy white, sometimes pink or red, 1–1 in across, with red anthers, held in flat clusters (corymbs) of up to twelve in spring. When cut, they give off a strong, unpleasant smell.
• Fruit: haws, small oval red pomes 0–1 in across, which ripen in fall and often hang on the tree into winter.
• Bark: grayish brown, becoming rough and very attractive with age.

It is often confused with common hawthorn (Crataegus monogyna). Midland hawthorn has leaves cut less than halfway to the midrib, two styles in each flower and two seeds in each haw, while common hawthorn has deeply lobed leaves and a single seed. It also blooms one to two weeks earlier. The two species hybridize to form Crataegus × media, which now includes the famous ‘Paul’s Scarlet’, with double, light red flowers. Among the cultivars of the species, ‘Crimson Cloud’ has single red flowers with a white center, and ‘Gireoudii’, a slow dwarf, stays under 13 ft.

Light

It grows in sun or partial shade, facing any direction, in exposed or sheltered sites. Full sun is still the best exposure. It tolerates cold winds and suits urban and coastal gardens.

Watering

Once established, Midland hawthorn is tough and copes with both wet soils and drier spells. After planting, however, keep an eye on watering during dry periods for the first three growing seasons. Rather than following a schedule, check soil moisture deep down before you water.

In a container, and especially as a bonsai, it needs a lot of water during the growing season: if the roots dry out, the leaf tips turn brown.

Potting mix

It adapts to almost any soil, whether chalky, clay, loam or sand, acidic, neutral or alkaline, moist but well drained or simply well drained. It prefers moist, fertile soil. Just avoid ground that is often waterlogged, where the roots can rot.

Temperature

This is a very cold-hardy plant, grown in USDA zones 4a to 8b, and it withstands the harshest continental winters, below -4 °F. In a pot, the root ball is more exposed to cold than roots in the ground: protect it from hard freezes and from excess winter rain.

Repotting

Plant bare-root trees while they are dormant, from late fall to late winter; container-grown plants can go in at any time. Stake a young tree for eighteen months to three years, until it is well rooted. Hawthorn is not a heavy feeder: a general-purpose fertilizer in late winter gives young plantings a boost and is no longer needed once the tree is established.

As a bonsai, repot every two or three years in spring, before growth begins, removing no more than a third of the roots.

Pruning

A tree needs little pruning: remove broken, poorly placed or diseased branches, ideally in the depth of winter dormancy. A hedge is trimmed twice or more from late spring through summer, with a last cut in early fall; if you need to cut it back by more than half, spread the work over two or three years. Hawthorn takes hard pruning well and sprouts from old wood. Wear thick gloves because of the thorns.

Propagation

• Seed: collect the haws while still green in late summer, soak them in warm water for several days to soften the flesh, then free the seeds by pressing the fruit against a sieve. Sow in containers outdoors: winter cold breaks dormancy, but germination is erratic the first year. Keep the seed tray through a second winter, as more seeds will sprout.
• Grafting: cultivars are sold grafted onto young hawthorns two or three years old; chip budding in summer is also possible.
• Cuttings: very hard with hawthorn; try seed first.

Common problems

• Fire blight: this bacterium, Erwinia amylovora, attacks pome-fruit members of the rose family from late spring to fall. Flowers wilt, shoot tips look scorched and cankers form. Promptly cut out affected parts well below the diseased area, disinfecting your tools between cuts, and burn the debris.
• Rust: cedar-hawthorn rust produces small yellow spots in spring that turn orange; by summer, small tubes form on the undersides of the leaves. Its cycle requires two hosts, hawthorn and a juniper, over two years. A severe attack makes the leaves yellow and drop, and can also infect fruit and young shoots.
• Leaf spot and powdery mildew: dark spots with gray centers, sometimes with yellowing, are unsightly but rarely fatal. The species is susceptible: a heavy attack can nearly defoliate the tree in early summer. ‘Paul’s Scarlet’ is very susceptible, while ‘Crimson Cloud’ is said to be more resistant. Powdery mildew appears mostly in dry weather.
• Pests and other diseases: aphids and caterpillars, rarely harmful, and leaf margin mites, which thicken and curl the leaf edges without serious damage; honey fungus, crown gall and silver leaf can also affect it. Rabbits and deer sometimes browse young plants.

The same symptom, such as a dying branch, can have several causes: drought, fire blight or a fungus.

Toxicity

Midland hawthorn is non-toxic to dogs, cats and horses. The haws are ornamental and not meant for pets. For people, the seeds contain toxins: remove them if you eat the fruit, which is used for jellies and chutneys. The sharp thorns can injure the skin.