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Rock cotoneaster

Cotoneaster horizontalis

Common names:
rock cotoneaster, rockspray

Content Detail

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.

  • Family (English) Rose
  • Family (botanic) Rosaceae
  • Tree or plant type Ground cover, Shrub
  • Foliage Deciduous (seasonally loses leaves)
  • Native locale Non-native
  • Size range Low-growing shrub (under 3 feet), Small shrub (3-5 feet)
  • Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
  • Hardiness zones Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7
  • Soil preference Moist, well-drained soil
  • Tolerances Alkaline soil, clay soil, Dry sites, Occasional drought, Road salt
  • Season of interest mid spring, late spring, early summer, midsummer, late summer, early fall, mid fall, late fall
  • Flower color and fragrance Pink
  • Shape or form Arching, Creeping, Mounded
  • Growth rate Moderate, Slow

Size and Method of spreading:

Rock cotoneaster is 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 a ground cover. This is a trailing plant that can be used as a low-growing shrub or ground cover. Trailing groundcovers have trailing stems that spread out from the central root system. These stems spread out horizontally over the ground, but do not root to the ground.

Native geographic location and habitat: 

This shrub is native to 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: 

The alternate leaves are rounded to elliptical, 1/2 inch long, dark green above, and lighter beneath.

Flower arrangement, shape, and size: 

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

Fruit, cone, nut, and seed descriptions: 

Bright red, showy, 1/4 inch diameter fruit (pomes) in late summer.

Plant care:

Rock cotoneaster does best in full sun. Good drainage is important. It can be used in container planting but will require winter protection. Can be pruned anytime to keep in bounds.

List of pests, diseases, and tolerances: 

Leaf spots, canker diseases, rust, and fire blight. Tolerant of poor soil, salt, and dry soils once established.

Hesse cotoneaster (Cotoneaster x ‘Hessei’):

Hesse cotoneaster is considered a hybrid between Cotoneaster horizontalis and Cotoneaster adpressus var. praecox. It is a low-growing shrub reaching 1 to 2 feet high.  A Chicagoland Grows™ introduction.

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