pears

Pears, like peaches, need to be winter-chilled. In general, they can be grown in the same regions as apples and peaches. They are hardier than peaches, but they flower earlier than apple trees, so watch for chills. Areas of consistent zero-degree winters are about the northern-most limit for pear trees, and with such temperatures winter-killing of the buds may occur.

Pear trees do well on poorer soil as long as it's well drained. In fact, very rich soil will produce overly lush growth, which in turn will encourage fire blight. Like Cassius, they should have a lean and hungry look.

STOCK

Self-sterile for the most part, pear trees are best ordered in different varieties if you want to be on the safe side, in which case they'll also need to be same-time bloomers. Buy one-yearold grafted whips around five feet tall. These should be about one-half- to three-quarters-inch thick, with smooth, even bark. Plant in early spring, on a northern slope where possible to protect them from premature flowering and a too-hot summer sun. Prune back about 25 percent on planting and don't use a fertilizer rich in nitrogen . . . this is one tree you don't want to grow very fast.

PRUNING

A minimum-pruning tree. After the initial planting trim, help shape it and remove root suckers when they form, but never give it a heavy pruning to boost growth. It would respond too well, and fire blight would follow only too often. Also very rapid growth makes the tree literally jump out of its skin . . . the bark splits, inviting borers and a multitude of other nuisances.