Do not apply fertilizer when planting a shrub, nor during the first season. If the shrub is doing well, feed it only once a year in the spring, as frequent fertilizing also encourages shrubs to grow faster. Never fertilize in late summer or fall when the shrub is adjusting to the coming winter season.
To keep the soil moist and to control weeds spread a 2 to 4 inch layer of some attractive organic material over the soil underneath Yews. Spread the mulch in a circle out as far as the drip line. Avoid piling it up against the base of the stems.
Yews lend themselves to routine pruning, responding well to shearing for hedges and topiary. Be aware, however, that repeated severe pruning may result in forlorn looking shrubs with a fringe of foliage on their perimeters and bare stems in the interiors. Besides, many types of Yews have beautiful natural growth habits and do not need anything more than removal of an occasional broken branch.
To keep tall-growing types under some control, clip half of the new growth on each stem every year with hand pruners to assure a more natural look. Sometimes very old Yews need rejuvenation, calling for a major pruning. With a pair of loppers or a pruning saw cut all their stems back to within 12 inches of the ground to stimulate new dense growth over the next 2 or 3 years.
Yews normally require supplemental watering only when they are first planted, in times of prolonged drought, and in the fall just before the ground freezes hard. Water once every week or 10-days during drought. Be sure to mulch around the base of the shrubs to help maintain soil moisture. Do not over water Yews. They do not tolerate soggy soil.
In northern parts of the country, broadleaf and needled evergreens sometimes suffer damage from harsh winter weather. During a winter warm spell, cold or frozen roots of trees and shrubs cannot adequately replace the moisture lost by their foliage. This dries out plant tissues, which appear as yellowed or “burned” needles, or dieback of entire branches. To prevent this problem, follow these steps:
Water the shrubs before the ground freezes, usually in October and November if rainfall has been scarce all fall. Soak the soil to a depth of 18 to 24 inches.
Spray with an anti-transpirant. Also called anti-desiccants, these products coat needles with a clear, flexible film that reduces their rate of moisture loss by up to 80% while allowing essential gas exchange. Follow label instructions.
Shield shrubs exposed to harsh winds with a length of burlap attached to stakes, snow fencing or white polyspun floating row cover which permit essential air flow around the shrub.
Spread a 2 to 6 inch layer of organic mulch on the soil over the root zone of your shrubs when the ground freezes. Spread it from near the trunk out to the drip line to moderate temperature fluctuations and prevent the soil from frost heaving.