When does European Alder bloom?

Alnus glutinosa flowers in March and April, before its leaves fully expand, producing separate male and female catkins on the same tree.

What kind of habitat does European Alder prefer?

This tree grows well in consistently wet or boggy soil and along streambanks, ponds, and floodplains, and it tolerates periodic flooding better than most trees.

What pollinators visit European Alder?

Bees, beetles, and flies visit Alnus glutinosa, drawn to the pollen produced by its early spring catkins.

How much sun does European Alder need?

It grows best in full sun but can tolerate part sun to part shade, especially when soil moisture stays high.

Is European Alder toxic to livestock?

The USDA PLANTS Database does not flag European Alder as toxic to livestock.

Is European Alder HOA-friendly?

European Alder takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

European Alder

Name: Pollinator Patch
Author: Pollinator Patch

Alnus glutinosa

Last reviewed: August 2026

European Alder (Alnus glutinosa) is a perennial tree. It blooms in March and April. The flowers draw bees, beetles, and flies.

Toxicity unknown

European Alder (Alnus glutinosa) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. 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 European Alder as toxic to livestock.

Light

full sun

Water

high

Size

360"–720" H × 240"–480" W

Bloom

Mar, Apr

Pollinators

bees, beetles, flies

Native alternatives to European Alder

European Alder is not native to the United States. These natives fill a similar role in a planting, matched on bloom season, bloom color and mature size.

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European alder is a large deciduous tree that thrives in wet conditions and poor soils. It grows 30-60 feet tall with a broad canopy and produces small catkins in early spring before the leaves emerge. This fast-growing tree is excellent for erosion control near water features or in boggy areas.

Growing European Alder

Grow European Alder in full sun and high water. Mature plants reach 360 to 720 inches tall and spread 240 to 480 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.

In an HOA neighborhood

European Alder takes more care to keep looking intentional in a front yard. Maintenance level: moderate. Consider it for backyard or mid-zone beds rather than the street edge.

Works well in: backyard only.

Non-native species may violate native landscaping requirements
Very large mature size can overwhelm residential lots
Requires consistently wet conditions that may be hard to maintain

Wildlife value

The early spring catkins provide important nectar for bees, beetles, and flies when few other flowers are available. Seeds feed birds like finches and redpolls, while the dense canopy offers nesting sites.

Common questions

When does European Alder bloom?: Alnus glutinosa flowers in March and April, before its leaves fully expand, producing separate male and female catkins on the same tree.
What kind of habitat does European Alder prefer?: This tree grows well in consistently wet or boggy soil and along streambanks, ponds, and floodplains, and it tolerates periodic flooding better than most trees.
What pollinators visit European Alder?: Bees, beetles, and flies visit Alnus glutinosa, drawn to the pollen produced by its early spring catkins.
How much sun does European Alder need?: It grows best in full sun but can tolerate part sun to part shade, especially when soil moisture stays high.
Is European Alder toxic to livestock?: The USDA PLANTS Database does not flag European Alder as toxic to livestock.
Is European Alder HOA-friendly?: European Alder takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

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

Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

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