Red Alder

Alnus rubra

tree

Red alder (Alnus rubra) is the great pioneer hardwood of the Pacific Northwest, a fast, slender tree to 65 to 100 ft, of streamsides, clearings, and wet lowlands from Alaska to California. Like all alders it fixes its own nitrogen through bacteria in its roots, so it enriches the soil and races ahead on poor, raw, or disturbed ground. Its bark turns a striking red-orange when cut or bruised and was a traditional dye and bark herb. Short-lived but quick, it is grown to stabilize wet banks, build soil in a young food forest, and supply bark, and its light canopy lets understory plants thrive.

✅ Plant alongside

Good neighbors that attract beneficial insects or deter pests

• Salal — A native evergreen shrub that thrives in the dappled shade beneath alder in the Northwest
• Elderberry — A moisture-loving shrub suited to the same wet ground, fed by the alder's nitrogen
• Comfrey — A nutrient accumulator that pairs with the soil-building alder in a young food forest

🛡️ Pest & disease prevention

Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide

• Heart rot (Phellinus) →

  Mainly afflicts older trees; use alder as a short-term nurse tree and remove it before it declines

• Tent caterpillars →

  Prune out the silk nests early; vigorous alder regrows quickly

• Alder sawfly/flea beetles →

  Chew the leaves but rarely kill the fast-growing tree; tolerate light damage

🌾 Harvest & storage

Harvest the bark in spring when it lifts easily and the red-orange color is brightest, taking it from coppiced stems, thinnings, or prunings rather than a standing trunk. The freshly cut bark stains red - the traditional dye - and is dried for use. Since alder grows so fast and resprouts when cut, a coppiced tree gives a renewable supply of young bark-bearing wood without loss of the stand.

🥗 Nutrition & benefits

Red alder is grown not for food but for its red-orange bark - a traditional dye and bark tea - and for the work it does in the soil. As a nitrogen-fixer it enriches poor and disturbed ground, making it a prized nurse tree in young food forests and a fast stabilizer of wet, eroding banks across the Pacific Northwest.