Gray Birch

Size, growth and what to expect

Gray birch grows fast, 2 to 5 feet a year on fertile ground, and about 2.75 feet a year in our growth estimator. Expect 20 to 40 feet with a narrow crown 10 to 20 feet wide, often on several trunks. It is short-lived, often lasting about 20 years and rarely more than 50.

Yellowish male catkins hang from the twig tips in April and May, while the small female catkins stand upright. The slender cones ripen in September and October. Goldfinches, pine siskins and chickadees eat the seeds, and ruffed grouse eat the male catkins and buds. The leaves turn yellow in fall.

It grows wild from Nova Scotia and southern Quebec to southern Ontario, and south to New Jersey and Pennsylvania. Small outlying stands grow west to northern Ohio, Indiana and Illinois. Others grow south through Delaware and Maryland to Virginia. It grows on dry sandy or rocky ground as well as along streams, ponds and swamps. It also turns up in a few counties of Kentucky, West Virginia and North Carolina, beyond its main range.

How to grow Gray Birch

Gray birch wants full sun and takes part shade, but not deep shade. It grows best in a moist soil that drains well, but it also grows in poor, dry or sandy ground. It takes wet ground but not long flooding. A soil with a high pH can yellow its leaves. It does best where summers stay cool and struggles in hot, humid ones. Plant it 15 feet from a wall and at least 15 feet from overhead wires, and set trees 15 feet apart.

Saplings ship bare-root or potted. Plant them dormant, as early in spring as you can or in fall once the leaves have turned, in a hole wider than the roots and no deeper. Set the root flare at the soil line, put the native soil back in, and keep the mulch clear of the trunks. Pick the cones in early fall, while they are still a little green. Sow the seed at once on the surface of moist soil, barely covered, since light helps it sprout. For spring, hold it damp in the refrigerator for 4 to 8 weeks first. Shade the seedlings lightly through their first summer.

Water weekly through the first two summers, and in dry spells after that. Keep grass and weeds well back from young trees, which grow poorly among them. Deer, moose and snowshoe hares browse the twigs in winter, so cage young trees. Avoid pruning in spring, when a birch bleeds sap.

Male and female catkins grow on the same tree, and the wind carries the pollen. Gray birch sets almost no good seed with its own pollen, so plant two or more seedlings if you want seed. Trees bear seed from about 8 years old, with a heavy crop every year. It seeds itself onto bare ground nearby and can sucker from the roots. Birch leaf miner can disfigure the leaves but does not kill the tree. It resists the bronze birch borer better than paper birch, and the borer seldom kills it. Ice and heavy snow can bend or break the slender trunks.