Alnus rubra
Alnus rubra
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Pl. 861E — Alnus rubra
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IOverview
Overview
Alnus rubra, commonly known as the Pacific or California alder, is a deciduous tree native to the Pacific Northwest and northern California. This member of the birch family (Betulaceae) thrives in moist, wet environments such as riverbanks and swamps. It can grow up to 20 meters tall with a width of 17 meters, making it an impressive ornamental addition to landscapes. Known for its edible value, Pacific alder is used by indigenous peoples who consume the flowers, inner bark, and sap. Its light requirement ranges from full sun to partial shade, and it prefers medium to heavy clay soils. Native to Alaska, British Columbia, California, Idaho, Montana, Oregon, Washington, and Yukon, this versatile tree plays a significant role in its ecosystem while offering culinary benefits.
Quick answers
What is Alnus rubra?
Alnus rubra, commonly known as the Pacific or California alder, is a deciduous tree native to the Pacific Northwest and northern California. This member of the birch family (Betulaceae) thrives in moist, wet environments such as riverbanks and swamps.
Growingconditions · propagation · uses
VCultivation
Cultivation
Alnus rubra thrives in full to partial sun and prefers moist to wet conditions, making it suitable for areas with medium or heavy clay soils. It is hardy in zones 7-8, though generally considered hardy in temperate regions. For cultivation, ensure the soil remains consistently moist; avoid drought stress. Propagation can be done through seeds or cuttings. Harvest flowers, inner bark, and sap as edible parts.
Light
Full sun, Partial sun/shade
Water
Moist, Wet
Soil
Medium, Heavy (clay)
Hardiness
7-8
Mature size
20.0 m × 17 m
For first-time growers
How to grow Alnus rubra for the first time
8steps
Start with planting Alnus rubra in a moist, well-draining soil and full to partial sun for the best beginner experience.
- 1
What you'll need
Alnus rubra saplings or seeds, garden gloves, spade or trowel.
- 2
Best time to plant
Plant Alnus rubra in spring after the last frost or fall before the first freeze.
- 3
Soil and container prep
Ensure soil is moist, well-draining, and rich in organic matter. Amend heavy clay with compost if needed.
- 4
Sowing or transplanting
Transplant saplings 3-4 meters apart for a healthy forest-like setting. Sow seeds directly into the ground in early spring.
- 5
First two weeks
Water regularly to keep soil moist but not waterlogged. Monitor for pests and diseases.
- 6
Ongoing care
Provide regular watering, especially during dry spells. Prune dead or diseased branches as needed.
- 7
Harvest or pruning
Prune in late winter to early spring before new growth starts. Harvest inner bark and sap for culinary uses.
- 8
Common mistakes
Overwatering, planting too deep, neglecting regular pruning, using chemical fertilizers.
VIEdible & utility
Edible & utility
Edible parts:FlowersInner barkSap
Edible uses: The inner bark and flowers of Alnus rubra can be eaten. The inner bark is typically harvested in late spring or early summer and used fresh or dried. The flowers are often collected when they first appear and may be consumed raw or cooked. Skip the sap as it is not commonly eaten.
Other uses:Fire starterDyeAnimal feedHedgerowPioneerWind breakerErosion controlTanninLumberNitrogen fixer
Contextrange · companions · related
VIIDistribution
8 native · 1 introduced
Distribution
8 native · 1 introducedDistribution across1 continent· 8 native· 1 introduced
Americas1 region
native (1)United States
Broader regions
native:Yukon, British Columbia, California, Idaho, Montana, Oregon, Washington
introduced:Argentina South
IXSpecimen gallery
1 image
Specimen gallery
1 imageXI
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Companion planting
Growing zone
XII
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Back to the cataloguePlant id · 861e7559-9360-45e4-a0ce-e2d6c9a41179
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