Betula nana aka Arctic Dwarf Birch

Betula nana is also known as dwarf Arctic birch. It belongs to the birch family, Betulaceae. This shrub sheds its leaves each year. It comes from northern Europe, Asia, and North America. Its range also reaches the mountains of Europe. It is native to Britain and Ireland. It grows in the wild on mountain moors. Unlike taller birches, it forms a low, spreading bush.

Sources give different sizes for plants grown in gardens. RHS lists heights of 0.3–1.6 feet [0.1–0.5 metres]. Its summary allows 2.5 feet [0.75 metres]. Oregon State gives 2–4 feet [0.6–1.2 metres], with a similar width. RHS gives a spread of 3.3–4.9 feet [1–1.5 metres]. In southern parts of its range, shrubs reach 5 feet [1.5 metres]. Arctic plants may stay near 1.5 feet [0.46 metres]. They may also lie closer to the ground. Branches may trail or rise to form a rounded crown.

The small leaves are almost round, with coarse, rounded teeth. Their tops are shiny green, while their lower sides look paler. The leaves turn red and yellow before falling in autumn. Thin twigs are dark reddish brown and may have sticky glands. Young shoots may have hairs but grow smooth with age. Shiny reddish-brown bark has many lenticels, or pores, running across it. Larger stems gain dull white marks. Male and female catkins grow on the same plant. These are clusters of flowers. Male catkins hang down and turn yellow-green as they open. Female catkins stand upright and have a reddish-green tint. Chicago Botanic Garden gives May to June as the bloom period. The fruit forms upright clusters shaped like cones. These hold winged nutlets, which ripen in late autumn.

Grow this shrub in sun or partial shade. It suits cool, moist sites, including swampy ground. Oregon State reports that it can also grow in dry sites. RHS lists sand, loam, clay, and chalk as suitable soils. It grows in acid, neutral, or alkaline soil. Hardiness ratings are USDA zones 2–5 and RHS H7. Its low shape suits rock gardens, borders, and ground cover. Plants can take 10–20 years to reach full size. Grow new plants from seed sown in autumn. You can also use softwood cuttings taken in summer.

Birch borers, leaf-mining sawflies, and aphids may attack the plant. Honey fungus, rust, and powdery mildew may also occur. Plants For A Future lists young leaves and catkins as edible raw. It lists buds and twigs for flavouring stews, with no known hazards. Records of past uses include bark remedies. People also made leaf mixtures for stomach complaints. These records do not prove that such treatments are safe or helpful. Other uses include leaf dye, hair treatments, tinder, and fuel.