Willowleaf Cotoneasters need about an inch of water each week. An inch of rain equals 2 gallons per plant, which you may also supply by watering for half an hour with a sprinkler.
During Spring and Summer make certain the plants get 1/2 to 1 inch of water a week during active growth.
During Fall and Winter reduce supplemental water from late August to mid-October to discourage excessive fall growth that might be susceptible to winterkill. Resume supplemental watering in the late fall and soak well prior to the ground's freezing solid. With their generally shallow root systems, shrubs can suffer moisture deficiency in the late winter without that last good drenching before the hard freeze sets in. For more information see file on About Watering Equipment.
Willowleaf Cotoneasters need only one application each year of fertilizer such as commercial sludge, compost, or a fertilizer. Spread the fertilizer on soil to 1-1/2 feet beyond the tips of the branches, and don't let fertilizer touch the plant. Follow fertilizer package directions to determine amount to apply and remember: more isn't necessarily better!
Apply the annual application of fertilizer in the spring. In summer Willowleaf Cotoneasters will look even better with a monthly spray of dilute liquid fertilizer mixed with dilute seaweed extract for the first three months after last frost. Stop feeding 2 months before first frost to encourage hardening off for winter. For more information see file on About Fertilizers.
Willowleaf Cotoneasters do best when they have a 2- to 4-inch layer of organic mulch over their roots all season long. Cover the soil out to the tips of the branches (drip line). Keep the mulch away from the main stem to avoid decay and rodent damage. Mulch with chopped leaves, pine needles or wood chips. Avoid mulching with un-chopped leaves, because they mat together and prevent water from reaching the soil. Peat moss also makes poor mulch, because it draws water from the soil like a wick and is difficult to rewet. For more information see file on Using Mulch.
Willowleaf Cotoneasters normally don't require any pruning, except for selectively removing branches to shape the plant or cutting out dead wood. For more information see files on Pruning Shrubs and Pruning Shrubs.