When does Grey Alder bloom?

Grey Alder flowers early, typically in February and March, with narrow catkins opening before the leaves emerge for the season.

How much water does Grey Alder need?

It grows best in consistently moist to wet soil and is often found along streambanks, floodplains, and wet meadows, though it can tolerate somewhat drier medium moisture sites.

What pollinators does Grey Alder support?

Bees, beetles, and moths visit and use Grey Alder, with the catkins providing an early pollen source when few other plants are flowering.

How much sun does Grey Alder need?

Grey Alder grows well in full sun to part shade, and it tends to thrive best with at least several hours of direct light each day.

What growth habit does Grey Alder have?

It grows as a tree, often with multiple trunks, and can form thickets in the moist, open sites it favors.

Is Grey Alder toxic to livestock?

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

Is Grey Alder HOA-friendly?

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

Grey Alder

Name: Pollinator Patch
Author: Pollinator Patch

Alnus incana

Last reviewed: September 2026

Alnus incana is a fast growing tree often seen along streambanks, wet meadows, and mountain drainages, producing slender catkins in February and March before its leaves unfold.

Toxicity unknown

Grey Alder (Alnus incana) 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 Grey Alder as toxic to livestock.

Light

part shade

Water

high

Size

180"–600" H × 180"–360" W

Bloom

Feb, Mar

Native to

AZ, CA, CO, CT and 27 more states

Pollinators

bees, beetles, moths

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Grey alder is a fast-growing deciduous tree that thrives in moist conditions and partial shade. It produces distinctive catkins in late winter to early spring and develops into a medium to large tree with attractive grey-green bark.

Growing Grey Alder

Grow Grey Alder in part shade and high water. Mature plants reach 180 to 600 inches tall and spread 180 to 360 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.

In an HOA neighborhood

Grey 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.

Grows very large (15-50 feet)
Requires consistently high water which may conflict with xeriscape preferences
Fast growth can appear uncontrolled

Wildlife value

The early spring catkins provide crucial nectar for bees, beetles, and moths when few other food sources are available. The tree also supports various bird species and provides habitat for wildlife.

Common questions

When does Grey Alder bloom?: Grey Alder flowers early, typically in February and March, with narrow catkins opening before the leaves emerge for the season.
How much water does Grey Alder need?: It grows best in consistently moist to wet soil and is often found along streambanks, floodplains, and wet meadows, though it can tolerate somewhat drier medium moisture sites.
What pollinators does Grey Alder support?: Bees, beetles, and moths visit and use Grey Alder, with the catkins providing an early pollen source when few other plants are flowering.
How much sun does Grey Alder need?: Grey Alder grows well in full sun to part shade, and it tends to thrive best with at least several hours of direct light each day.
What growth habit does Grey Alder have?: It grows as a tree, often with multiple trunks, and can form thickets in the moist, open sites it favors.
Is Grey Alder toxic to livestock?: The USDA PLANTS Database does not flag Grey Alder as toxic to livestock.
Is Grey Alder HOA-friendly?: Grey 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.

Native range data from vouchered herbarium specimen records and regional native plant society lists. 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

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