Birches Adorn Many Home Grounds

The name white birch alone may indicate one of several different species of trees with snowy white bark. Probably the most planted in our area is the European white birch which has graceful, slightly drooping branches as trees become older. The leaves are glossy and somewhat triangular. There are cutleaf, purple leaf, and other ornamental variations of this species which was originally introduced from Europe. More common in northern states is the paper or canoe birch. Its smooth white bark peels into thin, paper-like layers much more easily than most other birches, exposing a reddish-orange inner bark.

Its smooth trunk tends to develop less blackened areas than most other birches. Its leaf shapes tends to be fuller and less triangular than the European birch. It is a native tree to northern United States and Canada where it develops into its most beautiful forms. The gray birch is another tree with white bark, but smaller growing than the others. It does not have a drooping form, and is often used as a multiple-stemmed tree. It is native to the northeastern United States. Its leaves are somewhat similar to the European birch, but the teeth along the margins are slightly larger and the tip of the leaf tends to be more elongated.

The river birch is a native Missouri birch that is suitable for landscape plantings, but is a birch without white bark. It is a fast growing tree with peeling bark giving the trunk a very distinctive appearance. As the name indicates, it is native to low areas along rivers and streams. Therefore, it is well suited to moist locations where many other trees can not grow. Other birches like plenty of moisture but are not suited to wet spots and must be located in well drained soils.

One of the most serious pests of birches is the bronze birch borer which appears to be more abundant in recent years. The young insect tunnels beneath the bark of the trees and may kill upper branches before protective measures can be taken. The European birch is particularly susceptible while the paper birch is somewhat more resistant. Some Asian white birches are considered resistant, but their introduction has been much more recent and they are still not widely available.

Where bronze birch borers are a problem, spraying with an insecticide may be necessary to save the trees. Lindane, used in June and again in early July, helps control these pests. If trees are severely damaged, dead or dying limbs should be removed. Birches are also subject to some canker diseases that may infect the trunk. Care should be taken that trunks are not damaged during handling or while mowing the lawn. Sometimes leaf spot disease may appear in midsummer, causing premature drop of the leaves. Cleaning up leaves as soon as they fall is often adequate to prevent future serious infestations.

A fungicide applied in late spring helps clear up the problem if it continues to damage leaves. Birches like cool soil, and benefit from a mulch or ground cover over the roots. Young trees with thin foliage cover can be helped by such root protection. Since birches are not fond of hot, dry weather, be sure to proved adequate moisture in mid to late summer.

http://en.wikipedia.org/wiki/Birch_Tree