Rock cotoneaster shrubs offer a nice example of a plant with four-season interest. These rose-family members produce light-pink flowers in late spring, and their unusual branching pattern hosts glossy green leaves in summer. But rock cotoneasters really come into their own in autumn. They bear both attractive fall foliage and berries in the autumn months. The red berries stay on the branches a long time and remain attractive into early winter. They may show signs of shriveling and discoloration by mid-winter. By late winter the berries may attract hungry wild birds. Rock cotoneaster is easy to grow; in fact, for some gardeners, it may be a bit too easy to grow.
|Botanical Name||Cotoneaster horizontalis|
|Common Name||Rock cotoneaster, rockspray cotoneaster, wall cotoneaster|
|Plant Type||Deciduous shrub|
|Mature Size||3 feet in height and up to 8 feet in width|
|Sun Exposure||Full sun|
|Soil Type||Well-drained; young plants need evenly moist soil|
|Soil pH||6.75 to 7.5|
|Hardiness Zones||5 through 7|
|Native Area||Western China|
How to Grow Rock Cotoneaster Plant
Rock cotoneaster is an easy plant to grow in the sense that, once established, it will survive and thrive largely on its own unless you live in an area subject to severe droughts. It is one of landscaping's truly tough plants, usually spreading even when neglected. For some gardeners, however, its ability to spread so easily is a drawback: It takes some work to contain rock cotoneaster.
It is not necessary to prune cotoneaster plants unless you wish to contain their spread. And if you do prune them, don't prune off the ends of the branches, as you would, say, with yews (Taxus spp.). That would ruin their natural gracefulness.
That said, you might feel that a particular branch spoils the overall shape of the plant. In that case, follow the branch all the way back to the center of the shrub, and make your pruning cut there, so as not to leave an awkward stump behind.
Some growers do, indeed, want to restrict this plant's spread, and that is their reason for pruning it. Rock cotoneaster is one of those bushes that will strike down roots wherever one of its branches touches the ground. This enables it to spread quite a bit. Many people either are not interested in having the shrub spread that much or simply do not have the space to allow it to do so. If that describes your situation, then you will want to keep up with your pruning on this vigorous bush. Or, if low-maintenance landscaping is a priority for you, you may wish to skip rock cotoneaster altogether and grow a plant that is better-behaved, instead.
Give rock cotoneaster full sun for optimal berry production and fall-foliage color. But newly-planted cotoneaster plants need a bit of pampering, even though they are considered ground covers for full sun: Be sure to give them plenty of water.
It is not fussy about soil pH, although rock cotoneaster generally performs best in earth with a roughly neutral soil pH. Its main soil requirement is good drainage. A loamy soil works best.
Rock cotoneaster is a drought-tolerant shrub once established. But until it is established, water so as to keep its soil evenly moist.
Rock cotoneaster is not a heavy feeder. Add compost to the soil as needed.
What Rock Cotoneaster Looks Like
Its plant form is horizontally-spreading (thus the species name, horizontalis), which is why it's such a great ground cover, despite it potential to become 3 feet tall. The plants have small, roundish leaves. This fine texture provides a nice contrast with larger-leafed plants.
The fall foliage of its shiny leaves ranges from reddish-orange to burgundy. The light pink blooms of late spring yield later to equally shiny red berries (or "pomes"). The branching of rock cotoneaster is stiff and dense, giving the plant, overall, a rather bristly look. Stems shoot off the branches in what is often referred to as a "herringbone pattern." It is called this because it reminds you of the herringbone brick pattern sometimes found in patios and walkways. Actually, many would say it looks more like someone tried to form a row of V's along the branch, but failed. The left-hand strokes of the V's don't line up properly with the right-hand strokes, so that they never intersect.
Varieties of Cotoneaster
The cotoneasters are a diverse group of plants and are roughly divided into ground-cover types (such as C. horizontalis) and taller, more upright types. Two types of C. horizontalis are the cultivar, 'Variegatus' (known for its two-toned leaves) and the variety, perpusillus (known for staying as short as 1 foot in height). But there are also many species beside horizontalis; for example:
- C. dammeri is one of the shortest types, reaching just 8 to 12 inches tall (zones 5 to 8).
- C. divaricatus is one of the kinds that grow tall enough (up to 6 feet in height, with a spread of up to 8 feet) to be used in a hedge (zones 4 to 7).
- C. lucidus is another kind commonly grown in hedges. It grows to be 6 to 10 feet high and wide (zones 3 to 7).
- C. salicifolius is one of the taller types at 10 to 15 feet tall, with a spread of slightly less than that (zones 6 to 8).
Wildlife Attracted to Rock Cotoneaster, Uses in Landscaping
Birds, bees, and butterflies are all attracted by these bushes. But, fortunately, they are deer-resistant shrubs. Birds use cotoneaster berries as an emergency food source in winter.
The common name, "rock cotoneaster," alludes to the widespread use of C. horizontalis as a rock-garden plant. The common name, "wall cotoneaster," alludes to two other uses:
- Rock cotoneaster plant is often trained to grow up against walls.
- Grown at the top of a retaining wall on a hill, it will drape slightly over the side.
More broadly speaking, rock cotoneaster works well as a ground cover in any sunny spot where you need to have a plant that will fill in a patch of bare ground.
Name Origin, Mispronunciations
"Cotoneaster" is a widely mispronounced plant name. The correct pronunciation, technically, is cuh-TO-ne-AS-tuhr, but certain dictionaries give some legitimacy to the common mispronunciation, CAWT-tuhn-ES-tuhr. Others want to drop the first "e" altogether, fancying a combination of "cotton" and "aster."
In terms of the origin of the plant's name, "cotoneaster" comes from the new Latin word for "quince," cotneum, plus the suffix, -aster, meaning "imperfectly resembling." So a cotoneaster shrub is literally a plant that imperfectly resembles a quince. The reference is to Cydonia oblonga, not to the flowering quince (Chaenomeles spp.).