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Sitka alder

Alnus sinuata

Last reviewed: October 2026

Sitka alder (Alnus sinuata) is a perennial shrub native to CA, CO, ID, MT and 3 more states. It blooms in April and May. The flowers draw bees.

Sitka alder (Alnus sinuata)
Photo: Krzysztof Ziarnek, Kenraiz

Toxicity unknown

Sitka alder (Alnus sinuata) 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

120"–360" H × 96"–240" W

Bloom

Apr, May

Native to

CA, CO, ID, MT and 3 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 460 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 Sitka alder.

Fast-growing, multi-stemmed shrub with rounded toothed leaves and drooping catkins in spring, forming dense thickets along streambanks, avalanche chutes, and other disturbed moist sites at higher elevations.

Growing Sitka alder

Grow Sitka alder in full sun and high water. Mature plants reach 120 to 360 inches tall and spread 96 to 240 inches wide.

Wildlife value

Nitrogen-fixing roots improve soil for other plants, and dense thickets provide cover and nesting habitat for birds.

Common questions

How much sun does Sitka alder need?
Sitka alder grows best in full sun conditions.
When does Sitka alder bloom?
Sitka alder blooms in April and May.
Where is Sitka alder native?
Sitka alder (Alnus sinuata) is native to CA, CO, ID, MT and 3 more states, per the World Checklist of Vascular Plants (Kew).
What pollinators does Sitka alder attract?
Sitka 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 Sitka alder? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.