The cinnamon-colored, exfoliating bark of the River Birch is spectacular in the winter. Lustrous, medium-green leaves. Most borer resistant birch. Tolerant of both wet soils and dry summers. Avoid very alkaline soils. Prune only when dormant and not when sap is flowing. Grows to 40' to 70', 40'-60' spread. (zones 4-9)