← Back to Plant Finder

Speckled Alder
Alnus incana

A deciduous, thicket-forming shrub or small tree sometimes growing to 20' tall or more. This species has been planted as an ornamental at water edges. Its root mass prevents erosion on stream banks and enriches soil by making nitrogen available to other plants. Use this plant in restorations, pond edges, and acidic soil conditions.

USDA symbol: ALIN2

General Information

Plant TypeShrub
Height15 to 25 feet
Light ExposureSun, Part Sun
Soil MoistureMedium
Bloom ColorYellow, Red
Speckled Alder (Speckled Alder<div><em class="small">Alnus incana</em></div>)
Photo credit: Minnesota Wildflowers (Click to enlarge)


Flooding / Inundation ToleranceVery High
General Resilience6
Salt ToleranceMedium
Stress ToleranceFire Tolerant, General Disturbance

Pollinator Value: Medium

Bloom MonthsMarch to May
Larval Host ofMoths
Specific Pollinators HostedCaloptilia alnicolella, Sthenopis argenteomaculatus

Project Planning

Project TypeErosion Control, Restoration
Coefficient of Conservatism9
Herbivore SensitivityMedium
Rate of SpreadSlow
Soil StabilizationDeep
Vegetative ReproductionClonal


CountyAitkin, Anoka, Becker, Beltrami, Benton, Carlton, Cass, Chisago, Clearwater, Cook, Crow Wing, Dakota, Douglas, Goodhue, Houston, Hubbard, Isanti, Itasca, Kanabec, Kittson, Koochiching, Lake, Lake of the Woods, Mahnomen, Marshall, Mille Lacs, Morrison, Mower, Norman, Otter Tail, Pennington, Pine, Polk, Ramsey, Roseau, Sherburne, St. Louis, Stearns, Todd, Wabasha, Wadena, Washington, Winona, Wright
EcoregionDriftless Area, Lake Agassiz Plain, North Central Hardwood Forests, Northern Glaciated Plains, Northern Lakes and Forests, Northern Minnesota Wetlands, Western Cornbelt Plains
Approximate Eco ProvinceEastern Broadleaf Forest, Laurentian Mixed Forest, Prairie Parkland, Tallgrass Aspen Parklands