Gardening : <i> Cotoneaster congestus</i> , Cotoneaster

Small evergreen shrub with gray-green leaves and dark red berries

Cotoneasters come in dozens of shapes and sizes and habits, from evergreen to deciduous, with various degrees of leaf-dropping in between. The tallest is about 20 feet, the lowest a six-inch-high spreading ground cover.

They are reliable workhorses of the garden, filling space with dense little leaves and a shower of tiny pink or white flowers in spring, then returning to attention in winter with bright berries. They do all this without making any special demands; in fact, it’s best to plant cotoneasters where they won’t have rich, damp soil. Give them perfect drainage--a slope is best--and very little water, and they will be abundant and grateful.

Unfortunately, some cotoneasters suffer from fire blight and mealybugs. Treat the former misery without delay by pruning off the affected branches, sterilizing the shears after each cut with a disinfectant such as bleach. Burn these trimmings or put them in the trash; do not toss them on the compost heap or leave them lying around.

For the latter infestation, there is an alternative to sprays: predatory ladybird beetles and lacewings. These insects can be found at some nurseries or ordered from Natural Pest Controls, 8864 Little Creek Drive, Orangevale, Calif. 95662.

Some cotoneasters take to pruning more than others, but none are really suited to traditional hedge-like shaping and shearing, because the stem ends remain blunted and unattractive after they’re cut.

Cotoneaster congestus has leaves with a light, fuzzy underside, giving it a more noticeable role than its dark-leaved cotoneaster cousins. It is one of the lower evergreen shrubs, reaching about three feet in four or five years, with a rounded shape and branches that curve downward.

Cotoneaster dammeri, also called bearberry cotoneaster, is probably the most popular. A ground cover, it spreads 10 feet out but only six inches up; you can’t miss it in winter, when its brilliant berries flash like neon.

Cotoneaster horizontalis, despite its name, is not a ground cover; as high as congestus but much wider (flinging its branches out 15 feet), it is deciduous for just a few weeks. The leaves of C. horizontalis “Variegatus” are edged with white.