Pseudotsuga menziesii aka Douglas Fir

Douglas fir, Pseudotsuga menziesii, is a large evergreen conifer in the pine family, Pinaceae. It grows wild in western North America, from south-east Alaska and British Columbia to Mexico. Its range covers the Pacific coast and the Rocky Mountains. On the coast it climbs to about 5,500 feet (1,680 m). It is the state tree of Oregon and a leading timber species in the United States.

In gardens it usually reaches 40 to 80 feet (12 to 24 m) tall. Spread runs about 15 to 25 feet (4.5 to 7.5 m). Wild trees grow far larger, often past 200 feet (61 m). One Oregon giant reached about 329 feet (100 m). Young trees form a narrow cone, with drooping lower branches and rising upper ones. Older trees lose their lower limbs and develop a flatter, broader crown.

Bark on young stems is smooth and gray, with resin blisters. With age it turns reddish-brown, thick and deeply furrowed. Twigs are slender and red-brown, with long, sharp, non-resinous buds. The flat needles grow about 0.75 to 1.5 inches (2 to 4 cm) long. They range from dark green to yellow-green or blue-green. Two pale stomatal bands mark each underside. Crushed needles release a pleasant resinous scent.

The tree is monoecious and bears no showy flowers. Male cones are small, oblong and red to yellow. Female cones are reddish with long bracts. The hanging seed cones grow 3 to 4 inches (8 to 10 cm) long and ripen light brown in one season. A three-pointed bract sticks out from each scale, a feature that sets this tree apart. Birds and small mammals eat the seeds, while deer, elk and grouse browse the foliage.

Plant it in full sun in moist, well-drained, acid to neutral soil rich in organic matter. It copes with clay, loam or sand but dislikes chalk. It thrives where air and soil stay moist and summers stay cool. Heat, humidity, warm nights and long dry spells weaken it. It is hardy to UK rating H6. Hardiness varies with seed source, and inland Rocky Mountain trees handle cold and drought best. Small trees transplant easily, and the tree needs little pruning beyond removing rival leaders.

Growers raise it for lumber, plywood veneer and Christmas trees. In large spaces it serves as a specimen, screen or group planting. Its size rules it out for most home gardens. Strong winds can break branches.

Insect pests include adelgids, aphids, weevils, scale, spider mites and bark beetles. The Douglas-fir beetle is another threat. Diseases include needle cast, twig blight, cankers and several root and heart rots. Root rot is worst on wet or clay soils. Plants for a Future lists no known hazards. Young shoot tips flavour food, and the needles and twigs make a tea. People once ground the dried inner bark into flour as a famine food.