How to Grow and Care for Washington Hawthorn

Washington hawthorn, sometimes incorrectly spelled "hawthorne," is a small, thorny deciduous tree in the rose family with beautiful June flowers, colorful orange, scarlet, and purple fall foliage, and fruit that wildlife depend on for winter food. It is often used as a landscape tree or hedge; it grows best in full sun for flowering and fruiting but can grow in partial shade. It is also adaptable to many types of soils and pH levels.

Washington Hawthorn Care

Here are the main care requirements for growing a Washington hawthorn tree.

• Grow Washington hawthorn trees in full sun, where the soil has good drainage.
• Space the trees as privacy hedges 3 to 5 feet apart; as a specimen tree, give it at least 25 feet to spread out.
• Water young trees consistently; mature trees are drought-resistant.
  

Light

Although it can grow in partial shade, Washington hawthorn will like a sunny spot.

Soil

Washington hawthorns adapt well to many soil types and pH levels, including acidic, alkaline, loamy, moist, sandy, and wet and dry clay soils. It prefers well-drained soil, however. It's adaptable to urban pollution, as well.

Water

Water regularly in the beginning. Once established, they are reasonably drought-tolerant but still require watering to keep the trees hydrated.

Temperature and Humidity

This tree grows well in most of the United States, except in the coldest and hottest regions. The Washington hawthorn tree does not do well in very humid climates.

Fertilizer

Fertilize a Washington hawthorn tree every other year or so in the spring with a balanced fertilizer.

Types of Washington Hawthorns

• 'Princeton Sentry': A trademarked cultivar, this Washington hawthorn is a vigorous grower and is just about thornless.
• 'Fastigiata': This cultivar is also almost thornless, has more of an upright growth pattern, and produces smaller flowers and fruits.
• 'Winter King': Mostly thornless, this hawthorn produces clusters of white flowers in spring, red to purplish leaves in fall, and bright red fruits in the winter. It's also reported to be resistant to rust and fire blight. It grows best in problematic clay soil.
• 'Vaughn': This is a thorny hybrid between a Washington hawthorn and a cockspur hawthorn (Crataegus crus-galli) producing fragrant white flowers and red fruits.

Pruning

Little pruning is necessary though a Washington hawthorn can develop into a thicket if the tree is not trained properly. However, it can tolerate hard pruning without injury. Pruning should be done after blooms are gone or in the fall after its leaves drop. You may want to call a licensed arborist to prune any hawthorn tree with thorns. If you choose to prune a thorny hawthorn yourself, wear thick leather gloves, eye protection, and a helmet.

Propagating Washington Hawthorn

Nurseries propagate Washington hawthorn through grafting methods, which are best left up to professionals. Propagating hawthorn trees with cuttings is not ideal and results will be hit or miss. If you want to try cuttings, take hardwood cuttings in the early fall or winter. Then, take these steps as you would with any other cutting.

1. With a sterilized cutting tool, take a 6 to 10-inch cutting from a branch. Make sure the branch has a few nodes on it.
2. Dip the cutting into rooting hormone.
3. Put the cutting in a pot with well-draining soil. One node should be sticking up above the soil.
4. Put the pot outdoors or in a cold frame where it will root during the winter. You will probably need to keep the seedlings in a pot for an entire year before planting in the ground.
   

How to Grow Washington Hawthorn From Seed

Growing a Washington hawthorn tree from seed usually yields more success than from a cuttings but it is much slower. To grow the seeds, take these steps:

1. Harvest berries in the fall and clean off the seeds.
2. The seeds need stratification. Wrap seeds in a paper towel or sand that's moistened and place them in a zippered plastic bag. Though the time is not definitive, try putting the bag in the refrigerator for three to four months for a long dormancy period.
3. Sow seeds in a pot filled with a seed-starting mix that's well-draining. Cover seeds lightly with the soil.
4. Place the pot in a warm and bright space and keep the soil moist. The seeds will germinate in a few weeks or months (the time varies).
5. You will likely need to keep the seedlings in a pot for at least a year until they are strong enough to be planted in the ground.

Common Pests and Plant Diseases

The Washington hawthorn tree is one of the healthiest, disease- and pest-resistant hawthorns you can plant. However, stay on the lookout for common pests including aphids, borers, caterpillars, lace bugs, leafminers, and scale. Leaves may be discolored or skeletonized if there's a pest problem. Spraying these bugs off the tree with a garden hose or the use of insecticidal soaps can reduce many of these issues.

Though rust is a common problem with hawthorn trees, the Washington hawthorn does a good job of resisting cedar-apple rust. The tree is prone to sometimes fatal fire blight which kills blossoms and shoots, resulting in branch dieback. Washington hawthorn may also be afflicted with fungal leaf spots, powdery mildew, cankers, and apple scab.

How to Get Washington Hawthorn to Bloom

Bloom Months

The tree produces beautiful white clustering blooms from late spring to early summer, typically May through June. If you grow flowering specimens that bloom earlier in the spring (for example, flowering dogwoods), planting a late-blooming tree such as a Washington hawthorn can help bridge the gap between the spring's display of blooms and autumn's foliage show.

What Do Washington Hawthorn Flowers Look and Smell Like?

Clusters of small white flowers resemble apple blossoms. Flowers have a strong, sweet, and almond-like fragrance.

How to Encourage More Blooms

A Washington hawthorn that receives full sun and fertilizer will usually produce an abundance of healthy flowers.

Common Problems With Washington Hawthorn

Washington hawthorn trees may be less problematic than other hawthorns. The biggest problem is the thorns that can hurt when touched unless you can plant a thornless cultivar. Otherwise, here are a couple more problems to be aware of with this tree.

Weak Branches

Washington hawthorn trees, just like other unpruned hawthorns, may break apart in severe weather or ice storms. Train and prune the tree so it is a single trunk to avoid problems.

Browning Branch Tips

Branch tips that look burned with dangling dead brown leaves indicate fire blight. Prune out the affected branches and avoid using nitrogen fertilizer. There is no other preventative control.