Alnus Species, Italian Alder

A beautiful, tough, and extraordinarily adaptable tree, with handsome glossy, rich green leaves and a neat pyramidal to oval habit. Grows...Read More quickly even on difficult city sites with poor compacted soil. Reaches 30-50' tall.

It's cultivated in Europe, where it's commonly planted both for ornamental specimen use and as a windscreen. The Royal Horticultural Society has awarded it its coveted Award of Garden Merit. This is the most ornamental and adaptable alder species. Why it isn't more often grown in N. America is a mystery to me.

An excellent pioneer species, its only requirement is full sun. It tolerates boggy conditions and dry soils, alkaline or acid soil, sandy soils and clay, and tolerates pollution, wind, and salt spray. It resists wind-shaping. It fixes its own nitrogen and improves the soil. Grows fastest on moist soil.

Responds well to pruning. The cones are used decoratively in dried arrangements and Christmas decorations.

Leafs out early and holds its leaves late, often into December.

Dirr gives its hardiness range as Z5-7. The Missouri Botanical Garden says that it does not grow well south of Z7 (I assume they mean in hot-summer southeastern N. America and not in the PNW). http://www.missouribotanicalgarden.org/PlantFinder/PlantFind...