Culture
Best grown in medium to wet, well-drained, sandy or rocky loams in full sun to part shade. Prefers some afternoon shade in climates with hot, humid summers. Requires consistently moist soils. Consider using soaker hoses and bark mulches to keep the root zones cool and moist. Little prunning is required, but if necessary, prune during the dormant season. Avoid pruning in spring when the sap is running. Performs best in cool northern climates (USDA Zones 5 and 6) where root zones are often covered with snow in the winter.
Noteworthy Characteristics
Betula utilis, commonly called Himalayan birch, is native to temperate, montane forests of the Himalayas. It is a medium sized tree that typically grows to 30-40’ (sometimes to 60-70') tall with an open pyramidal habit. Ovate, double-serrate, yellow-green to green leaves (to 2-3" long) turn golden in fall. Tiny monoecious flowers appear in late spring in separate catkins on the same tree: yellowish-brown male flowers in drooping catkins (to 3-5” long) and greenish female flowers in much smaller, upright catkins (to 1.5” long). Female flowers are followed by drooping cone-like fruits containing numerous small winged seeds that typically mature in early autumn. The peeling bark can add seasonal interest.
Genus name is the Latin name for birch.
Specific epithet from Latin means useful.
Problems
In the St. Louis area, this birch grows poorly and is generally short-lived. It thrives in cool northern summers, but does poorly in climates with hot, humid summers. Weakened birches become very vulnerable to the bronze birch borer which typically infects and kills trees that are stressed by summer heat and humidity. In addition, Japanese beetles may significantly damage the foliage. Although these birches have some susceptibility to aphids, birch leaf miner, birch skeletonizer and dieback, these problems are usually considered to be somewhat minor in comparison to the birch borer. Stressed plants seem somewhat more susceptible to cankers.
Uses
In cool northern climates, this birch is an excellent landscape tree that displays a graceful form and mixes well with evergreens. Consider using river birch instead of Himalayan birch in the St. Louis region.