When does River Hawthorn bloom?

River Hawthorn typically flowers in May and June, producing small clusters of white blossoms before its fruit develops later in the season.

What growing conditions suit River Hawthorn best?

This shrub does well in full sun to part shade with medium soil moisture, and it is commonly found near streams, wetland margins, and open thickets.

What insects pollinate River Hawthorn flowers?

Bees, beetles, and flies visit River Hawthorn blossoms and are considered its primary pollinators.

Is River Hawthorn a tree or a shrub?

River Hawthorn grows as a shrub, often forming dense, thorny thickets rather than a single trunk.

Is Black Hawthorn toxic to livestock?

The USDA PLANTS Database does not flag Black Hawthorn as toxic to livestock.

Is Black Hawthorn HOA-friendly?

Black Hawthorn is generally an HOA-friendly choice in the right placement, with moderate maintenance.

Black Hawthorn

Name: Pollinator Patch
Author: Pollinator Patch

Crataegus douglasii

Last reviewed: October 2026

River Hawthorn is a thorny deciduous shrub with white blooms in May and June. It favors full sun and medium moisture, often growing along stream banks, woodland edges, and moist thickets.

Black Hawthorn (Crataegus douglasii) is not on the ASPCA Animal Poison Control Center toxic plant list for dogs or cats (aspca.org (opens in new tab), last reviewed 2026-05-21). If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

The USDA PLANTS Database (opens in new tab) does not flag Black Hawthorn as toxic to livestock.

Light

full sun

Water

medium

Size

120"–360" H × 96"–240" W

Bloom

May, Jun

Native to

CA, ID, MI, MN and 5 more states

Pollinators

bees, beetles, flies

Before you buy

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Browse plants for this ecoregion

Coast Range Puget Lowland Marine West Coast Forest Northwestern Forested Mountains Sierra Nevada Central California Foothills and Coastal Mountains North American Deserts Central Basin and Range Northwestern Glaciated Plains Northwestern Great Plains

River hawthorn is a deciduous shrub that grows 10-30 feet tall and wide, forming a rounded canopy. It produces clusters of white flowers in late spring followed by small red berries, and its glossy green leaves turn yellow to orange in fall.

Growing Black Hawthorn

Grow Black Hawthorn in full sun and medium water. Mature plants reach 120 to 360 inches tall and spread 96 to 240 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.

In an HOA neighborhood

Black Hawthorn is an HOA-friendly choice. Maintenance level: moderate. Tidiness: 3 out of 5.

Works well in: backyard only.

Very large mature size may overwhelm smaller properties
Thorny branches require careful placement away from walkways
Can appear irregular in shape without pruning

Wildlife value

The flowers attract bees, beetles, and flies in May and June. Birds feed on the berries in late summer and fall, while the thorny branches provide nesting sites and protection.

Common questions

When does River Hawthorn bloom?: River Hawthorn typically flowers in May and June, producing small clusters of white blossoms before its fruit develops later in the season.
What growing conditions suit River Hawthorn best?: This shrub does well in full sun to part shade with medium soil moisture, and it is commonly found near streams, wetland margins, and open thickets.
What insects pollinate River Hawthorn flowers?: Bees, beetles, and flies visit River Hawthorn blossoms and are considered its primary pollinators.
Is River Hawthorn a tree or a shrub?: River Hawthorn grows as a shrub, often forming dense, thorny thickets rather than a single trunk.
Is Black Hawthorn toxic to dogs?: Black Hawthorn is not on the ASPCA Animal Poison Control Center toxic plant list for dogs (aspca.org).
Is Black Hawthorn toxic to cats?: Black Hawthorn is not on the ASPCA Animal Poison Control Center toxic plant list for cats (aspca.org).
Is Black Hawthorn toxic to livestock?: The USDA PLANTS Database does not flag Black Hawthorn as toxic to livestock.
Is Black Hawthorn HOA-friendly?: Black Hawthorn is generally an HOA-friendly choice in the right placement, with moderate maintenance.

These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.

Native range data from the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

If something looks wrong

Common plant problems, and what to check first

These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.

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