Alnus RubraThis beautiful deciduous tree is one of the primary species that naturally regenerates and thrives in disturbed sites and poor soils throughout our region. The quantity of nitrogen that Red Alder pulls from the air and stores in its tissue and underground in root "nodules" (through a process called nitrogen fixation) is unparalleled among plants that can be grown in the Northwest. Both its wood and leaves contain high amounts of nitrogen, with the leaves being 3% nitrogen in the fall when they drop – as well as containing significant phosphorus. One Red Alder can provide enough nitrogen for 3 fruit trees nearby. Red Alder will grow 20' or more in its first 4 years and can be pruned easily to allow light penetration beneath it. It does not sucker when cut and is a highly valuable timber wood for finish carpentry. For all these reasons and more, we plant and grow this native tree in our agroforestry systems and take great joy in its beauty, astounding growth, fertilization abilities and the habitat it provides. One excellent use for alder in urban environments is to plant it to the South and West of a house where it will provide much appreciated shade during the hottest months – after only 1-2 years! Because it drops its leaves in winter it will not impede views or light during the months when those aspects are most important. Plant more Alder.
USDA Zone 3-8p/>
Time to productivity: In 10-20 years you can harvest good timber or firewood. Can provide nitrogen to neighboring plants within 2 years.
Size: 80' tall or more when mature.