Vaccinium deliciosum aka Cascade Bilberry

Vaccinium deliciosum is a low, deciduous shrub in the heath family. Its common names include alpine blueberry and Cascade bilberry. It comes from western Canada and the western United States. Its range includes southwest British Columbia, Washington, Oregon, and northern California. It also occurs in parts of Idaho. This mountain plant grows in subalpine or subarctic climates.

Plants stand about 1–1.5 feet [0.3–0.46 metres] tall. Underground stems spread outward and can form dense mats. Stems also take root where they touch the ground. Young twigs are red-green, with a slightly angled shape. Older bark turns gray and peels in strips. The leaves grow one at a time along each stem. They range from oval to broadest near the tip. Each leaf has a wedge-shaped base and fine teeth. The teeth may cover only the upper part. Leaves are pale blue-green above, with a waxy coat beneath. They turn red to purple before falling in autumn.

Small pink flowers hang alone from the leaf axils. Their joined petals form an almost round cup. Each flower holds both male and female parts. Insects pollinate them during the May to June bloom. Blue berries ripen in late summer beneath a waxy coat. Fruit size ranges from about a quarter to half an inch. Ripe berries taste sweet and have a rich scent. Eat them fresh, cook them, or dry them for storage.

Grow this shrub in moist soil that drains well. It suits sandy or loamy ground rich in leaf mould. It needs acid soil, with a preferred pH of 4.5–6. Lime in the soil can cause leaves to turn yellow. Plants grow in full sun or light shade. A sunny spot gives better fruit crops. Shelter them from strong winds and avoid disturbing their roots. PFAF lists USDA hardiness zones 5–9. Its separate UK zone rating should not imply an RHS hardiness rating.

This low shrub suits a moist rock garden or planted bed. It also fits the sunny edge of a woodland garden. Its spreading stems provide ground cover, while autumn leaves add colour. Plants can spread fast where conditions suit them. PFAF does not flag the species as weedy. Seed, layering, and half-ripe cuttings offer ways to raise new plants. Cuttings can be slow and hard to root. PFAF lists no known hazards or medicinal uses. That does not establish the safety of every plant part.