Rock cotoneaster

Leaves and branch structure of rock cotoneaster.

Rock cotoneaster is a low spreading shrub often used as a ground cover or left to spill over slopes and ledge walls. The densely branched plant has glossy, dark green foliage, deep red fruits and reddish purple fall color.

This plant has some cultivated varieties. Go to list of cultivars.

 

Botanical name:

Cotoneaster horizontalis

All Common Names:

rock cotoneaster; rockspray

Family (English):

Rose

Family (Botanic):

Rosaceae

Tree or Plant Type:

  • Ground cover,
  • Shrub

Native Locale:

  • Non-native

Landscape Uses:

  • Container,
  • Foundation,
  • Hedge,
  • Massing,
  • Mixed border,
  • Patio/sidewalk

Size Range:

  • Small shrub (3-5 feet),
  • Low-growing shrub (under 3 feet)

Light Exposure:

  • Full sun (6 hrs direct light daily),
  • Partial sun/shade (4-6 hrs light daily)

Hardiness Zones:

  • Zone 5 (Chicago),
  • Zone 6,
  • Zone 7

Soil Preference:

  • Moist, well-drained soil

Tolerances:

  • Dry sites,
  • Occasional drought,
  • Alkaline soil,
  • Clay soil,
  • Road salt

Season of Interest:

  • Mid spring,
  • Late spring,
  • Early summer,
  • Mid summer,
  • Late summer,
  • Early fall,
  • Mid fall,
  • Late fall

Flower Color & Fragrance:

  • Pink

Shape or Form:

  • Arching,
  • Creeping,
  • Mounded

Growth Rate:

  • Slow,
  • Moderate

More Information:

Size and Method of spreading

This is a trailing plant that can be used as a low-growing shrub or ground cover.  It grows 2 to 3 feet high.  It is a trailing ground cover.  Trailing ground covers have trailing stems that spread out from central root system.  These stems spread out horizontally over the ground, but do not root to the ground.

Tree & Plant Care

A low shrub reaching 2 to 3 feet tall and spreading 6 to 8 feet wide. The horizontal branches create a dense layer effect, similar to ground cover.
Best in full sun. Good drainage is important.
Can be used in container planting but will require winter protection.
Can be pruned anytime to keep in bounds.

Disease, pests, and problems

Leaf spots, cankers, rust and fire blight

Disease, pest, and problem resistance

Tolerant of poor soil, salt and dry soils once established.

Native geographic location and habitat

Western China

Bark color and texture 

Finely textured branching, in a herringbone that pattern creates a layered effect.

Leaf or needle arrangement, size, shape, and texture

Alternate, rounded to elliptical, 1/2-inch long, dark green above, lighter beneath.

Flower arrangement, shape, and size

Small, 1/4-inch pink flowers in late May.

Fruit, cone, nut, and seed descriptions

Bright red, showy, 1/4-inch diameter fruit in late summer. 

Cultivars and their differences 

Hesse Cotoneaster (Contoneaster x 'Hessei'): Hesse cotoneaster is considered a hybrid between Cotoneaster horizontalis and Cotoneaster adpressus var. praecox.  
A low-growing shrub reaching 1 to 2 feet high.  A Chicagoland Grows™ introduction.

 

Location of Cotoneaster horizontalis (Rock cotoneaster) at the Arboretum