How to Care for a Mature Yew Hedge

Irrigate the hedge only on an as-needed basis, since too much water causes the foliage to turn yellow. Yew shrubs are intolerant of overly moist or wet soils and prefer a watering schedule that keeps the soil evenly moist to lightly dry. Water the soil when the top 3 inches feel dry. Use a garden hose to provide enough water to moisten the soil to a depth of 10 to 12 inches.

Spread a 2-inch-thick layer of organic mulch around the base of the mature hedge to retain soil moisture and limit weed infestations. Keep the mulch several inches from the trunk, as direct contact may cause rot. Organic mulching materials include wood chips, pine bark and shredded leaves.

Prune mature yew hedges two times a year, preferably in early to mid spring and again in midsummer. Use sharp, sterilized pruning shears to clip off old, damaged or diseased growth from the hedge. Cut back overgrown branches to maintain the overall shape of the hedge.

Trim the hedge whenever needed to maintain its shape and appearance. Use sharp clippers to snip off wayward branches or growth that extends beyond the overall form of the hedge, back to the trunk. Discard fallen clippings from around the base of the hedge to prevent pests, spores and other disease-spreading organisms from overwintering.

Pull out any weeds around the hedge with a gloved hand or hoe on a regular basis. Weeds compete with yews for soil moisture and nutrients, depriving them of essential elements necessary for development.

Enrich the soil with two to three shovelfuls of organic compost or well-rotted manure every spring when the danger of frost is over. Loosen the soil around the mature hedge carefully with a trowel and incorporate the organic soil amendment to improve drainage and aeration. However, work carefully so you do not damage the roots.

Treat common yew pests such as Taxus weevil, scale insects and mealybugs with insecticide to prevent damage.