Once established, cotoneaster hedges require watering only during long periods of drought. Water the plants once the soil becomes completely dry, making sure that the water reaches the roots. Never apply fertilizer directly to cotoneaster hedges, as it may increase the possibility of the plant developing an illness. Instead, apply chemicals to plants that grow at least 10 feet away from the hedges. Prune hedges lightly toward the end of winter to shape them.
Cotoneaster hedges grow well in the areas that are exposed to the sun during the entire day. The soil should have sufficient drainage. Plant the hedges about 6 to 10 feet away from one another, as they become much wider as they grow.
Gardeners don't need to water these plants if the soil occasionally dries out for short periods of time. However, cotoneaster grows best if the soil is somewhat moist. Usually, if the cotoneaster grows next to other plants that require regular watering, it receives enough moisture for healthy growth. When pruning the hedges, apply some alcohol to the shears after each cut to prevent disease from spreading. Remove any dead, broken or crossed branches up to the healthy wood.
In addition, remove any branches that have developed oozing cankers, as they are infected with fireblight infection. If the plants become infected with mites, aphids or scale, spray them with an insecticidal soap solution.