Plant of the Week: Cotoneaster Horizontalis

By Davis Landscape Architecture @DavisLandArch

Cotoneaster horizontalis berries (Cambridge, 03/11/2011)

Position: Full sun to partial shade

Flowering period: Late Spring to Early Summer

Soil: Well-drained

Eventual Height: 0.5m (2m against a south wall)

Eventual Spread: 1.5m

Hardiness: USDA Zones 5a – 7b

Family: Rosaceae

Cotoneaster horizontalis a low growing deciduous shrub with a ground hugging growth habit. It will grow vertically when planted against a south facing wall, hugging the wall face. It’s leaves are dark green in spring and summer, becoming orange and red in autumn. The leaves of the plant are small and glossy, arranged alternately arranged and ovate to lanceolate, with entire leaf margins. The bark is smooth and gray in color. The stems have a fishbone pattern. The flowers which are produced in May and June are generally produced in corymbs of up to 100 together and range  in colour from pink to white. These are followed by red pomes (berry like fruits) in late summer which contain three to five seeds.

Cotoneaster horizontalis, commonly known as Herringbone Cotoneaster, Rock Cotoneaster, Rockspray Cotoneaster or Wall Cotoneaster, is native to China. It is a short shrub that is usually cultivated as an ornamental plant especially in public parks. It is believed that this species of Cotoneaster was introduced into Britain in 1879. C. horizontalis was added to the Wildlife and Countryside Act Schedule 9 Part 2 plants list in 2010, this makes it an offense to cause the plant to grow in the wild.

The etymological root of the binomial name Cotoneaster is derived from the old Latin name cotone ’quince’, aster being a Latin substantival suffix indicating ‘resembling’. Horizontalis is derivedfrom the Latin meaning horizontal, in reference to the growth habit of this plant. 

Cotoneaster horizontalis (Cambridge, 03/11/2011)

The landscape architect should not specify Cotoneaster horizontalis as it is included in Schedule 9 Part 2 of the Wildlife and Countryside Act which makes it an offense to cause the plant to grow in the wild, this is open to interpretation and includes this plant being spread by birds.

Ecologically, the flowers are attractive to bees and the berries are attractive to birds.

C. horizontalis has been awarded the prestigious Royal Horticultural Societies annual Award of Garden Merit in 1993.

C. horizontalis prefers a humus rich, well-drained soil. It will tolerate most pH of soil.

Maintenance: This plant requires little maintenance. Any unwanted self sown seedlings may be removed as required.