Birch

The term "betula" means "pitch" and alludes to the fact that bitumen was distilled from birch bark. This was used as a glue for broken clay pots in Roman times.

These are trees with alternate, simple, toothed leaves and are most prized for their bark which may be in some shade of white and may also be exfoliating. Most birches fall into the group called "bleeders" which means that sap will flow from pruning wounds made in the spring. So, they are best pruned any time after the first flush of growth or during the dormant season when the leaves are absent.

 

Betula alba European White Birch
B. albo-sinensis Chinese Paper Birch
B. alleghaniensis
(B. lutea)
Yellow Birch
B. dahurica Dahurian Birch
B. ermanii Erman Birch
B. grossa Japanese Cherry Birch
B. jacquemontii Whitebarked Himalayan Birch
B. lenta Sweet Birch
B. maximowicziana Monarch Birch
B. nana Dwarf Birch
B. nigra River Birch
B. occidentalis Water Birch
B. papyrifera Canoe Birch
B. pendula European White Birch
B. platyphylla Asian White Birch
B. populifolia Gray Birch
B. schmidtii Schmidt Birch
B. utilis Himalayan Birch
B. verrucosa European White Birch


Many of the birches are susceptible to damage from two insect pests. The birch leaf miner will eat between the layers of the leaves causing the leaves to turn brown and, in severe cases, defoliate the tree early in the growing season.

In itself, leaf miner damage stresses the tree but rarely kills it. However, the weakened tree is then more attractive to a much more serious pest called the bronze birch borer. This critter will bore into the wood and kill the tree starting from the top and working its way down the trunk.
 

 

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