No tree has more beautiful bark than a white-barked birchthe tree that comes to mind when most people think of birches. Trouble is, these trees are often difficult to keep alive in most of the South. Native to mountainous areas, where summers are cooler and winters long, they tend to struggle when faced with the hot summers common to our region. And they often succumb to a serious pest: the bronze birch borer, which causes them to die slowly from the top down.
Fortunately, a number of birches that resemble white-barked birches do succeed here; they too have a graceful habit; thin bark that peels in sheets; and small, finely toothed leaves that turn glowing yellow in fall. After the leaves drop, the trees' delicate limbs, handsome bark, and small, conelike fruit provide a striking winter display.
B. lenta. SWEET BIRCH, CHERRY BIRCH. Zone US; USDA 6. Native to eastern U.S. Seldom sold. An attractive tree with shiny reddish to blackish brown bark; grows to 4050 ft. tall, up to 40 ft. wide. Leaves to 4 in. long; turn rich yellow in fall. Many country children have sampled the bark of this tree, which has a sweet wintergreen flavor and was once routinely used to make a tasty soft drink known as birch beer.
B. maximowicziana. MONARCH BIRCH. Zones US, MS; USDA 6-7. Native to Japan. Fast growing; open growth when young. Can reach 80100 ft. tall, 40 ft. wide. Flaking, orange-brown bark eventually turns gray or white. Leaves up to 6 in. long. Plants sold under this name are not always the true species.
B. nigra. RIVER BIRCH. Zones US, MS, LS, CS; USDA 6-9. Native to eastern U.S. Very fast growth in first years; eventually reaches 5090 ft. tall, 4060 ft. wide. Trunk often forks near ground, but tree can be trained to a single stem. Young bark is apricot to pinkish, very smooth, and shiny; on older trees, bark flakes and curls in cinnamon-brown to blackish sheets. Diamond-shaped leaves, 13 in. long, are bright, glossy green above, silvery below. This is the best birch for hot, humid climates. Not a good choice near decks and porches; drops leaves sporadically all summer. Tolerates poor drainage. 'Cully' ('Heritage') is resistant to bronze birch borer and has darker leaves and tan-and-apricot bark; keeps apricot color longer than the species. 'Dura-Heat' is more compact and heat tolerant than the species. 'Summer Cascade' is the first weeping birch that resists birch borer; grows 15 ft. tall and 20 ft. wide.
B. papyrifera. PAPER BIRCH, CANOE BIRCH. Zone US; USDA 6. Native to northern part of North America. Similar to B. pendula but taller (to 100 ft. tall, half as wide), less weeping, with a stouter trunk that is creamy white. Bark peels off in papery layers. Leaves are larger (to 4 in. long), sparser. Excellent fall color. More resistant to bronze birch borer than B. pendula. 'Snowy' is a cold-hardy selection with especially handsome white bark; it is said to be particularly resistant to borers and grows quickly when young.
B. pendula. EUROPEAN WHITE BIRCH. Zone US; USDA 6. Native from Europe to Asia Minor. Delicate and lacy. Upright branching with weeping side branches. Average mature tree is 3040 ft. high and half as wide. Bark on twigs and young branches is golden brown; as tree matures, bark on trunk and main limbs becomes white, marked with black clefts. Oldest bark (at base of tree) is blackish gray. Rich green, glossy leaves to 212 in. long, diamond shaped with slender, tapered point. Often sold as weeping birch, although trees vary somewhat in habit and young trees show little inclination to weep. Very susceptible to bronze birch borer. The following are some of the hybrids and selections offered.
'Crimson Frost'. Hybrid between B. pendula 'Purpurea' and an Asian birch, with burgundy leaf color that persists all summer. Somewhat resistant to borers.
'Fastigiata' PYRAMIDAL WHITE BIRCH. Branches upright; habit somewhat like Lombardy poplar (Populus nigra 'Italica'). Excellent screening tree.
'Laciniata' ('Dalecarlica'). CUTLEAF WEEPING BIRCH. Graceful, open tree with deeply cut leaves, strongly weeping branches. Weeping forms are more affected by dry, hot weather than is the species; foliage will show stress by late summer.
'Purple Rain'. A purple-leafed selection like 'Purpurea', but it holds its color all summer.
'Purpurea' (B. alba 'Purpurea') PURPLE BIRCH. Purple-black twigs. Foliage is rich purple-maroon when new, fading to purplish green in summer; looks striking against white bark.
'Youngii'. YOUNG'S WEEPING BIRCH. Slender branches hang straight down. Resembles weeping forms of mulberry (Morus) but is more graceful. Decorative tree. Trunk must be staked to desired height. Same climate limitations as those of 'Laciniata'.
Birches need a steady supply of moisture at all times; drought in summer can cause leaf drop. All fall victim to aphids that drip honeydew; for this reason, they should never be planted near a porch, patio, or parking area. Plant in fertile, slightly acid soil; most prefer good drainage. Prune in summer to remove weak, damaged, or dead branches; trees will bleed sap if pruned in winter. Susceptibility to heat and the bronze birch borer limits most birches to the Upper and Middle South.