Pinus strobus aka Eastern White Pine

Eastern white pine, Pinus strobus, is a needled evergreen conifer in the pine family, Pinaceae. It is native to southeastern Canada and the eastern United States. Its range runs from Newfoundland and Manitoba south to Georgia and west to Iowa. It is the state tree of Maine and Michigan. Gardeners have introduced it widely in Europe, including Britain, and in Korea.

This is a fast-growing, long-lived tree. In gardens it reaches 50 to 80 feet (15 to 24 m) tall and 20 to 50 feet (6 to 15 m) wide. Wild trees pass 100 feet (30 m), and records exceed 200 feet (61 m). Young trees form a neat cone or pyramid. With age the crown becomes broad, open and irregular, with branches set in tiers.

The soft, flexible needles are bluish green and 3 to 5 inches (8 to 13 cm) long. They grow in bundles of five, with fine white lines of stomata. Each needle lasts about two years before it drops. Young bark is smooth and gray-green. Older bark turns reddish brown to dark gray, with long scaly ridges and deep furrows. In spring, small yellow male cones and pinkish-green female cones appear, around March to April. Wind carries the pollen. The brown, resinous seed cones are slender, curved and 4 to 8 inches (10 to 20 cm) long. They take two seasons to ripen and release seed in late summer. Trees seldom bear cones before five to ten years of age.

White pine does best in full sun, though young trees cope with light shade. It likes fertile, moist, well-drained, acidic soil and a cool, humid climate. It copes poorly with compacted clay, alkaline soil, road salt and air pollution. In clay it may turn yellow from chlorosis. It is very cold hardy, to USDA zone 3 and RHS rating H7.

The tree makes a fine specimen for lawns, parks and other large spaces. You can shear it into a hedge, though the top grows fast once shearing stops. Dwarf and columnar cultivars suit smaller gardens. People also grow it for Christmas trees. Its light, straight-grained wood was a major timber in the 18th and 19th centuries. Birds, bears, squirrels and rabbits eat the seeds. Beavers, porcupines and mice gnaw the bark. The branches give cover to birds and small mammals. Deer and rabbits rarely damage it. The tree is highly flammable, so keep it away from houses.

White pine blister rust is the most serious disease and often kills the tree. Currants and gooseberries carry this rust, so do not plant them nearby. Other diseases include blights, cankers, needle cast and honey fungus. White pine weevil often kills the leading shoot, leaving a crooked top. Other pests include bark beetles, shoot borers, sawflies, scale, aphids and adelgids. The weak wood breaks in strong wind, ice and heavy snow.

Several parts are edible. The small seeds can be eaten raw or cooked, mostly as a flavouring. People brew the needles into a tea rich in vitamins A and C. The tender shoots can be candied, and the inner bark is also used. Wood, sawdust and resin may cause skin irritation in sensitive people. People with asthma or bronchitis should avoid taking it internally.