Washington Hawthorn Plant Care

Washington Hawthorn (Crataegus phaenopyrum) belongs to the Rosaceae family within the Crataegus genus. Washington Hawthorn is native to Eastern United States. Washington Hawthorn is also known as Washington Thorn.

Washington Hawthorn displays a small to medium-sized deciduous tree growth habit, reaching up to 30 ft tall with a spread of approximately 25 ft. Washington Hawthorn produces clusters of white or pink blossoms.

Leaf size: approximately 3 inches.

Water a young or newly planted Washington Hawthorn every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Washington Hawthorn thrives in full sun to partial shade.

Crataegus phaenopyrum tolerates temperatures of 0–100°F. Washington Hawthorn prefers humidity levels of 40–70%.

Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Washington Hawthorn to prevent waterlogging, which leads to root rot and fungal issues.

Feed Washington Hawthorn every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun to partial shade and well-draining loamy soil with added compost for nutrients. Avoid low spots where water collects after rain.

Washington Hawthorn is suited to USDA Zone 4 – 8.

Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.

Washington Hawthorn can spread to about 25 ft (7.6 m) and reach about 30 ft (9 m) tall. Space plants about 25 ft (7.6 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the tree spacing calculator.

Prune Washington Hawthorn while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the tree in one year.

Washington Hawthorn is hardy down to USDA zone 4, so once established it can stay outdoors through winter in that zone and warmer ones.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown trees need extra protection: roots in a pot freeze much more easily than roots in the ground.

Washington Hawthorn can be propagated through seeds, hardwood cuttings. Similar propagation techniques also apply to cockspur hawthorn plant care, which shares the same genus.

See all plants toxic to cats and plants toxic to dogs.

Washington Hawthorn is susceptible to aphids, caterpillars, scale insects. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Washington Hawthorn grows outdoors in USDA Zone 4 – 8. It survives winters down to planting zone 4a. Washington Hawthorn is native to Eastern United States.