Thornless cockspur hawthorn tree

Hawthorn (Crataegus)

  • Branches often have sharp, woody thorns.
  • Small, colorful, apple-like fruits.
  • Leaves are small, simple, alternate, and deciduous, with serrated edges (often lobed).
  • Leaves commonly have a leafy flange along their stalk.
  • May grow as a small tree or shrubs in dense stands.

Hawthorn is a large and diverse group of trees. Literally hundreds of different species and varieties have been developed for ornamental planting. Perhaps the most distinctive features of hawthorns are sharp woody thorns and small, colorful, apple-like fruits. Hawthorns are commonly planted because of their beautiful flower clusters and their colorful fruit.

Two species of hawthorn are native to Oregon, although others have been distributed far-and-wide by birds and humans. The two Oregon natives are relatively easy to tell from one another when they have fruit, but may be difficult at other times.

black hawthorn: tree or shrub; black fruit; thorns usually shorter than 1″.

Columbia hawthorn: only grows as a shrub; red fruit; thorns usually longer than 1″ (will not be described further).

For more information on the cherries and plums native to the Pacific Northwest, go to the species page or see “Trees to Know in Oregon”.

Washington State

Crataegus monogyna

Family: Rosaceae

Other Common Names: common hawthorn, red hawthorn, one-seed hawthorn, Neapolitan medlar, whitethorn
Weed class: C
Year Listed: 2016
Native to: Asia, Europe, and Northern Africa
Is this Weed Toxic?:

not known to be

Why Is It a Noxious Weed?

Plants can form thickets and block animal movement. In fact, this plant was used historically used in hedgerows to contain livestock. Its dense growth can alter the structure of forest understories and open grasslands. Hybridization can occur between English hawthorn and the native hawthorn, Crataegus douglasii, altering the gene pool of the native species and creating competition for resources and pollinators. In Europe and New Zealand, Crataegus monogyna is a host of fire blight bacterium (Erwinia amylovora) which also affects pears and apples.

How would I identify it?

General Description

English hawnthorn is a long-lived, deciduous, small tree to large shrub. Its branches have sharp thorns and the leaves are deeply lobed. White flowers, which can have a pink tint, bloom in May and develop red fruits in the fall.

Flower Description

Flowers are clustered in groups of 10-20 on short stalks. Each has five septals and five white petals that age to a pinkish color. Five to twenty-five stamens with pink-purple anthers extend past the petals.

Leaf description

Leaves are deciduous, alternately arranged and closely clustered on short shoots. Leaves are variable in shape and are mostly ovate (egg-shaped) to triangular in outline with 3 to 7 deep, sharp, lobes. The leaves are wide, leathery in texture, and can be glabrous (smooth and hairless) or hairy. Leaf edges are toothed, mainly near lobe tips.

Stem description

Stems usually branch from a single trunk. Twigs can be hairless and smooth or hairy and are often tipped with thorns.

Fruit Seed Description

English hawthorn produces bright to deep red, drupe-like pome fruits that are elliptic to spherical in shape with one to two nutlets with one seed each found in each fruit.

May Be Confused With

The native black hawthorn (Douglas’s hawthorn), Crataegus douglasii, is in the same genus but has characteristics to distinguish it from English hawthorn, Crataegus monogyna. Crataegus douglasii, which occurs all over Washington, has weakly lobed leaves (not prominently lobed), flowers with 5 styles (not 1 style), and blackish fruits (not bright red). See photos of Crataegus douglasii here at the UW Herbarium’s image database.

Where does it grow?

English Hawthorn grows in lowland areas on many soil types, growing best in moist soil or in areas with high precipitation, though established trees can survive moderate drought conditions. Please click here to see a county level distribution map of English hawthorn in Washington.

How Does it Reproduce?

English hawthorn reproduces by seed. Fruit drops to the soil beneath the tree and is also dispersed by animals, primarily by the American robin.

How Do I Control It?

General Information

Due to English hawthorn’s thorns, make sure to wear gloves and other protective clothing when working with plants. Make sure to monitor for seedlings as birds can disperse seeds far from plants. Frequently monitor habitats where English hawthorn may grow to find and control plants when they are small.

Manual/Mechanical Control

Manual removal of seedlings and small plants is possible and is easier to accomplish when the soil is moist. Seedlings can be hand-pulled, but small plants will need to be dug out including all the roots or at least the crown and upper portions of the roots to prevent resprouts. Plants can be cut back with the best time being in early summer as the plant is putting most of its energy into aboveground growth. Larger shrubs and trees can be cut to the base with chain saws or hand saws. Avoid cutting the plants when they are full of ripe fruit as they will be dispersed when moving and disposing of plant material. Remove the cut material from site as English hawthorn can regenerate from cutting. Plants will resprout unless the roots are removed or the cut surface is treated with herbicide. Burning the cut surface with a torch may also reduce sprouting.

Cultural Control

It is unknown how effective fire may be at controlling English hawthorn. A study cited in Zouhar (1998) by Pendergrass et al. (1998) reported that on the wet prairies of Oregon’s Willamette Valley, the density of nonnative, invasive shrubs which included English hawthorn, was not significantly altered by either a single fall burn or two consecutive fall burns. It was pointed out though that repeated burning over time may gradually reduce the density and slow the expansion of the invaders.

Biological Control

There are not any approved biological control agents for English hawthorn. Its spines typically deter grazing.

Herbicide Control

Currently there isn’t information on English hawthorn control in the PNW Weed Management Handbook but check back for information as it is continually being updated or contact your county noxious weed coordinator. Using a cut stem treatment on English hawthorn has shown success. Freshly cut stems, cutting as close to the ground as possible, can be painted with herbicide. Foliar sprays have not been as reliable for control and there is more risk of damage to non-target plant. Always read and follow the herbicide label instructions.

For More Information

See our Written Findings for more information about English hawthorn (Crataegus monogyna).

King County Noxious Weed Control Board information on English hawthorn.

Excerpt from the book Weed Control in Natural Areas in the Western United States

In the Garden

Q: We recently moved into a house with a hawthorn tree in the front yard. The tree had beautiful red blooms in spring, but now it has developed unsightly black spots on the leaves. Is there a way to prevent this?

A: Your tree is undoubtedly ‘Paul’s Scarlet’ hawthorn (Crataegus laevigata ‘Paul’s Scarlet’). This hawthorn sports gorgeous clusters of deep-pink double flowers in spring.

Unfortunately, it’s highly susceptible to a fungus disease known as hawthorn leaf blight. The first symptom is spotting on the leaves. The disease won’t kill your tree, but it will cause it to drop its leaves, and by midsummer you’ll be stuck with a bare tree until next spring. Fungicides labeled to help control this disease are rarely successful, and the leaf-dropping will occur every year.

Gardening Events

Heronswood Garden Summer Open & Plant Sale:

heronswoodgarden.org

Molbak’s Share Your Harvest:

molbaks.com

Magnuson Children’s Garden Family Days:

6:30 p.m. to 8 p.m. Tuesday, July 26. Family-friendly activities in the Children’s Garden with a Beatles tribute band, Creme Tangerine, in the amphitheater next door. Free. Address: Amphitheater and Children’s Garden, inside the Community Garden, at Magnuson Park, 6344 N.E. 74th St., Seattle.

magnusonnatureprograms.com

Fortunately, if you like hawthorns, there are plenty of attractive disease-free replacements.

Lavalle hawthorn (Crataegus x lavallei) develops a rounded habit and usually grows to about 20 feet tall. The clusters of spring flowers are white, followed by showy, brick-red fruit, and glorious coppery red fall color. The Washington hawthorn (Crataegus phaenopyrum) also sports attractive white flowers. It grows to about 25 feet with glossy red berries, and the leaves turn brilliant scarlet-purple in autumn.

If you’re hooked on red flowers, the English hawthorn ‘Crimson Cloud’ (Crataegus laevigata ‘Crimson Cloud’) is resistant to the disease and offers fiery clusters of single red flowers starred with white centers, followed by small red fruit. Replace it in fall while it is unattractive; however, if you are a superstitious sort, you better wait until spring. According to Gaelic and Irish folklore it’s very unlucky to cut down a hawthorn tree at any time other than when it is in full bloom.

Q: Please tell me how to kill poplar stumps. I cut the trees down because they were sending up suckers, and now they’re putting up twice as many shoots and they’re coming up all over my yard.

A: Poplars are famous for suckering, and the problem only gets worse if you cut them down. The reason they continue to sucker is because cutting down the tree doesn’t kill the roots, which then send up suckers to produce the food necessary to keep them alive.

In theory, if you cut off every sucker right as they emerge before they develop enough foliage to produce food, it would starve the roots and cause them to die off. Unfortunately, that could take years, and it takes only a few missed suckers to keep the cycle going.

Hence, this is one case where it’s usually necessary to resort to using a chemical herbicide to solve the problem.

Begin by mixing a systemic herbicide containing glysophate (such as Roundup) in a disposable container at the concentration indicated on the label for killing stumps and suckers. Then cut the stumps close to ground level, and immediately use a sponge paint brush to cover the entire surface of the stump with the herbicide, making sure to thoroughly cover the outside edges.

The herbicide will be absorbed and will kill the roots directly under the stumps. It won’t kill the ones farther out, however, and you’ll need to do the same thing to the suckers.

Follow-up treatments might be required if a new set of shoots appears, but if you stick with it, eventually the last of the underground roots will die off and the suckering will end. Follow all safety conditions on the label, and remember that glysophate will kill most anything it hits, so use caution when working near valued plants. Most important, consult a nursery professional to help you choose a replacement tree that doesn’t have a tendency to sucker.

Thornless Hawthorn tree berries

It appears that your Thornless Hawthorn tree may be infected with a Gymnosporangium Rust either Hawthorn or Quince Rust. Since Quince Rust primarily attacks the fruit and tender stem growth as opposed to Hawthorn Rust which produces leaf lesions and rarely produces orange to rust colored spore-filled blisters on the fruit surface, your tree is probably infected with Quince Rust. Fruit infected with Quince rust are covered with protruding aecia of the fungus.
Both cultural and chemical controls are necessary in dealing with this problem. According to the University of Minnesota extension, If applied before infection occurs, protective fungicides can be used to control the disease on Rosaceae plants like the Thornless Hawthorn. Typically, this occurs when flower buds first emerge and continues until spring weather becomes consistently warm and dry. Nearby infected junipers can be monitored and fungicides applied when gelatinous orange spore producing structures appear on galls and branches. Chemical treatments should have listed the following active ingredients include.

    • Myclobutanil- most effective!
    • Copper
    • Sulfur

Proper cultural practices are still the cornerstone of any management program to help trees and shrubs deal with stresses imposed by insect and disease attack. The University of Minnesota Extension recommends the following practices:

  • Do not plant eastern red cedar and juniper plants within a few hundred yards of susceptible Rosaceae plants. This will reduce but will not completely eliminate disease problems.
  • Prune and remove brown woody galls found on the eastern red cedar and juniper plants before orange gelatinous spore producing structures form in spring to reduce the level of infection on nearby Rosaceae plants.
  • Prune and remove infected twigs or branches on Rosaceae plants when they occur.

Below are links to the University of Minnesota Extension website that provide more information about these diseases:

Types Of Hawthorn Trees: How To Grow Hawthorn In The Landscape

Hawthorn trees are a delight to have in the landscape because of their attractive shape, shade potential, and clusters of pink or white flowers that bloom in spring. Songbirds love hawthorns, too, and they’ll visit often in fall and winter to enjoy the bright-colored berries. Most hawthorn trees grow 15 to 30 feet tall—the perfect size for urban gardens.

Growing hawthorn plants comes with its share of problems because they are susceptible to a number of diseases, including apple scab, fire blight, leaf spots, leaf blights and several types of rust. Some of the diseases are potentially fatal, and they leave the foliage and twigs looking tattered by the end of the season. If you decide to grow a hawthorn tree, look for a disease resistant variety such as ‘Winter King’ or ‘Washington’ hawthorn.

Types of Hawthorn

There are so many different types of hawthorn trees that it’s difficult to choose just one. Here are a few to consider:

  • Crataegus crus-galli var. inermis is commonly called thornless cockspur hawthorn. It has a lovely orange-red fall color and three-inch clusters of white flowers that bloom in spring.
  • C. laevigata ‘Crimson Cloud’ is an English hawthorn with bright red flowers and fine-textured leaves.
  • C. phaenopyrum, called Washington hawthorn, is more disease resistant than most. The leaves go through a succession of color changes and the flowers are bright white.

How to Grow Hawthorn

Hawthorn trees need full sun and well-drained soil. They tolerate almost any type of soil and variations in pH.

Set the trees out in spring so they’ll have a full season to become established before winter. In large settings they look great in groups, and they are pretty enough to stand alone as specimens in small gardens. Although they make great lawn and street trees, avoid planting thorny varieties where children play or where pedestrians pass. The thorns are fierce, and can be as much as three inches long.

Water the trees during dry spells for the first year. Afterward, they are drought resistant.

Feed hawthorns annually for the first three years with a balanced fertilizer and every other year thereafter.

Additional Hawthorn Care

Hawthorn trees need little pruning. Remove suckers that arise from the base of the trunk. You can trim the canopy, if necessary, to keep it looking neat. Make cuts just beyond a lateral twig or bud that faces the direction in which you want the branch to grow.

You might want to make routine spraying a part of your hawthorn tree care plan. Hawthorns are bothered by lace bugs, aphids, mites and scale, and these insects can get out of control unless you treat them early. Use a lightweight horticultural oil early in the season. You can damage the tree by spraying with horticultural oils at the wrong time, so read the label instructions carefully before spraying. Use a general-purpose spray labeled for hawthorn trees later in the season.

Thornless Cockspur Hawthorns – Growing A Thornless Cockspur Hawthorn Tree

Cockspur hawthorn is a flowering tree with horizontal branches spiked with large thorns. Thornless cockspur hawthorns are a user-friendly variety that allow gardeners to invite these North American natives into the garden without those thorny branches. For information about thornless hawthorn trees, including tips on how to grow a thornless cockspur hawthorn, read on.

About Thornless Cockspur Hawthorns

Anyone having a close relationship with a cockspur hawthorn (Crataegus crus-galli) probably has scratches to show for it. These dense shrubs, native to eastern Canada and the United States, bear long, sharp thorns that can draw blood.

Like the species plant, thornless cockspur hawthorns grow into rather short trees with broad, rounded canopies and horizontal braches. They top out at about 30 feet (9 m.) tall and equally wide. Thornless

hawthorn trees usually are low-branched with dense foliage. Sometimes they are seen growing as large, flat-topped shrubs.

Thornless hawthorn trees sport dark-green leaves during the growing season, then flame red, orange and yellow in autumn. The trees lose their leaves in the winter and regrow them in the spring. White flowers that appear in early spring turn into red berries. These berries ripen in fall. They hang on the trees well into winter, providing desirable food for wild birds and small mammals.

Growing a Thornless Cockspur Hawthorn

If you are thinking of growing a thornless cockspur hawthorn, you’ll find the tree an ornamental delight in a garden. They have the distinct advantage of not being armed and dangerous, as well as the best characteristics of the hawthorn. These deciduous trees grow in U.S. Department of Agriculture plant hardiness zones 4 through 8.

If you want to know how to grow a thornless cockspur hawthorn, the first tip is to plant it in a sunny location. They need six hours of direct sun to thrive.

Caring for thornless hawthorn and keeping them healthy is easier if you plant them in moist, well-drained soil. They grow in both acidic and alkaline soil.

Although thornless hawthorn trees develop drought tolerance, you can avoid any possibility by proper irrigation. Make an occasional water part of your routine in caring for thornless hawthorn trees.

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