How much sun does White alder need?

White alder grows best in full sun conditions.

When does White alder bloom?

White alder blooms in February and March.

Where is White alder native?

White alder (Alnus rhombifolia) is native to CA, ID, MT, OR and 1 more states, per the World Checklist of Vascular Plants (Kew).

White alder

Name: Pollinator Patch
Author: Pollinator Patch

Alnus rhombifolia

Last reviewed: November 2026

White alder (Alnus rhombifolia) is a perennial tree native to CA, ID, MT, OR and 1 more states. It blooms in February and March. The flowers draw bees.

Watering reminders and freeze alerts for White alder, free in the app.

Toxicity unknown

White alder (Alnus rhombifolia) 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.

Light

full sun

Water

high

Size

360"–960" H × 240"–480" W

Bloom

Feb, Mar

Native to

CA, ID, MT, OR and 1 more states

Pollinators

bees

Before you buy

Your city may pay you to plant this

Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 461 programs across 44 states, each with a link to the provider and the date we last checked it.

Find rebates in your area

Picture natives in your own yard

Upload a photo of your yard and Patch Vision shows a rendering of it planted with natives for your region, like White alder.

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Browse plants for this ecoregion

Coast Range Marine West Coast Forest Northwestern Forested Mountains Sierra Nevada Central California Foothills and Coastal Mountains Central California Valley Southern California Mountains North American Deserts Sonoran Basin and Range Southern California/Northern Baja Coast

Tall deciduous tree with smooth gray bark and oval toothed leaves, producing drooping catkins in late winter before leaves emerge. Grows along streambanks and in moist canyon bottoms, often forming a canopy over water.

Growing White alder

Grow White alder in full sun and high water. Mature plants reach 360 to 960 inches tall and spread 240 to 480 inches wide.

Wildlife value

Streamside cover and leaf litter support aquatic insects that fish and birds depend on. Early catkins provide pollen for bees.

Common questions

How much sun does White alder need?: White alder grows best in full sun conditions.
When does White alder bloom?: White alder blooms in February and March.
Where is White alder native?: White alder (Alnus rhombifolia) is native to CA, ID, MT, OR and 1 more states, per the World Checklist of Vascular Plants (Kew).
What pollinators does White alder attract?: White alder draws bees.

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.

See all plant problem guides

Ready to grow White alder? Add it to your garden in the Pollinator Patch App to track it and get season-by-season care guidance.

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