Correct pruning increases fruit size, sugar content and improves color and skin texture. Pruning for good light penetration and accessibility for thinning and picking improves disease and insect control because the sprays penetrate better. Correct pruning does require a lot of time. A large apple or pear tree may require 1 to 3 hours of detailed work. The time is well spent if you value the tree's beauty and the quantity and quality of fruit.
(See below for advice and tips for pruning each of the most popular varieties of apple.)
WHY The flowers are commonly borne on spurs. The fruit-bud is recognized by the following characters: it is much larger than the wood-bud; it is usually very pubescent or hairy; it is wider than long; and it is much wider than the diameter of the spur that bears it. The fruit-bud does not increase the length of the spur once it is formed, but below it a vegetative bud may develop that is held in check or in a dormant condition while the fruit is maturing and absorbing all the nourishment sent into the spur branch. Once the fruit matures and is removed, the vegetative shoot gains its chance to grow out slightly during the next season and then it forms a fruit-bud for the following season. This accounts for the alternating fruit bearing seasons, particularly with most varieties of apples.
WHEN There are some varieties that tend to bear fruit every year and can be induced to do so by June pruning and thinning out. The formation of fruit-buds is also related to a nutritional factor and seasonal pruning. We find that summer pruning is a stimulus to fruit-bud formation, while any other seasonal pruning is more conducive to vegetative or wood formation, particularly if the pruning is done in excess. Removal of "thin wood" is recommended in the spring months before the growth starts, or even better in June or July when the fruit is on the tree; pruning at this later period also thins out excess fruit.
HOW The narrow crotch, spaced lateral branches, and the pyra-midal-shaped tree with a central axis are factors in the care of Apple trees. Thinning out is also essential to allow a little sunlight throughout the inner part of the tree. But do not clean out the inner part of the tree so that the limbs are stripped to nearly the end, suggesting a "Mule-tail." The maximum height of a tree depends on conditions and varieties, but the average height should not exceed the need of using a ladder longer than 20 to 22 feet to pick the fruit from the top. Pruning in most orchards is done in the dormant season, at which time the heavy summer growth is thinned out and the general framework of the tree is retained, leaving the branches as evenly spaced as possible. The process of topping lightly means the removal of 30 percent of the season's summer growth; it is thought to induce greater possible fruit-bud production. Heavy pruning means the removal of 60 percent of the season's new growth and results in a stimulus to vegetative or wood growth. The latter method is best for young trees that are making a normal, rapid growth. However, additional thinning of the fruit crop in June is wise, since the period between May to July is always characterized by the expression "June drop," which means that during this period a natural adjustment takes place between the amount of fruit that is on a branch and the amount that the limb can actually carry on to maturity. Some of the immature fruit will fall off. One recent method of pruning suggests the removal of "thin wood". These are branches that are thin and tend to grow downward, particularly when laden with some fruit. The fruit produced on them is smaller and of poorer quality. These branches are usually crowded, shaded, and generally condemned as unproductive.
Some trees grow twiggy naturally, and certain apple varieties such as Jonathan, as well as many varieties of cherries, plums, peaches and apricots, need additional thinning of their bearing wood to let in sunshine to ripen the fruit.
Trees bear their fruit either on the limbs or on short, stubby spurs between the branches. Pears, plums and cherries grow mostly on spurs, peaches grow on one-year-old limb growth, and most varieties of apples are produced both on spurs and on limbs.
Because spur-type fruit trees make less limb growth, they need less pruning. Since this means considerably less labor for the orchardist, scientists have worked on breeding trees that produce mostly on spurs, and there are now many varieties of this type of fruit tree available.
When too many fruit spurs develop along a branch, cut out some of them to encourage bigger and better fruits on the rest. After a few years of experience, you'll be able to judge about how many spurs are right for the tree. Each spur will usually produce for several years, but then you should cut it off to allow a replacement to grow. You'll be able to spot the older spurs by their aging appearance.
As a novelty, some nurseries sell three-in-one or five-in-one apple trees, and some even feature trees with plums, cherries, peaches, nectarines and apricots all growing on the same tree. Some people like to graft several varieties of fruit on their own single tree too, either for the fun of it, or because they have a small growing area.
These multiple-variety fruit trees are difficult to prune. However, if you have one or feel you must buy or graft your own, you can prune them if you take some precautions. You will have to remember each year where the different varieties are located or else you're likely to cut off the only limb bearing a certain kind of fruit. If you don't have a good memory, you can tie ribbons of various colors to identify each variety. Multiple-fruit trees usually must be grown with an open center, since there will be three or more strong limbs. Each different kind of limb will grow at its own rate and in a different manner, so corrective pruning will be necessary to produce a well-balanced tree. It's a big job, but it you keep at it, you can avoid bad crotches, water sprouts, and lopsided growth.
Apple, Cortland - pruning
WHY To encourage large fruit.
HOW This tree has a spreading, somewhat drooping habit of growth, so don't allow it to branch too close to the ground. Prune and thin it to encourage large fruit. Open the top for good color, and brace the limbs if they droop too low.
Apple, Delicious - pruning
WHY For giant-sized fruit.
HOW A dense grower, this tree will form many weak crotches if left to itself, so it needs careful pruning. Without overpruning, allow in lots of sunlight. Thin it heavily for giant-size fruit.
HP Book - Central-leader trees, such as 'Red Delicious' apple, tend to grow into upright, columnar trees. You can counteract that tendency by placing small boards or spreaders between branches, forcing the branches to grow apart.
Apple, Duchess of Oldenberg - pruning
WHY For heavy crops
HOW This is a rugged, semiupright, medium-size tree. It bears on limbs and on short spurs, and will yield heavy crops annually for a long time if you keep it pruned and thinned.
Apple, Early McIntosh - pruning
WHY To correct its natural habit of forming bad crotches.
HOW This is a semiupright, large tree. It needs careful pruning and thinning to correct its natural habit of forming bad crotches. It tends to bear biennially, producing small to medium-size fruit.
Apple, Empire - pruning
HOW A semiupright growing tree, producing small to medium-size, high-colored fruit of excellent quality. Although an annual bearer, it will benefit from regular pruning and some thinning. It bears mostly on short spurs.
Apple, Grannie Smith - pruning
HOW This high-quality apple tree can be grown only in the warmer areas offering a long growing season. It is an annual bearer, and requires ordinary pruning.
Apple, Holly - pruning
HOW A semiupright, medium-size tree. Expect good crops annually. The fruit is of excellent quality and color. This tree requires ordinary pruning.
Apple, Honeygold - pruning
WHY Increase the size of fruit.
HOW A semiupright tree, bearing medium-size apples that taste much like the Yellow Delicious. Thinning and pruning will increase the size of the fruit. Although this is a hardy tree, it's not a good choice in the areas that have very short growing seasons.
Apple, Jersey Mac - pruning
WHY Keep fruit from dropping early.
HOW This is an early-ripening McIntosh. It's a large tree with a spreading habit, and is an annual bearer of good-quality fruit. The fruit tends to (drop)early, but heavy thinning helps.
Apple, Jonagold - pruning
WHY To correct its twiggy habit of growth.
HOW This is a large, semiupright tree. You will have to prune it heavily to correct its twiggy habit of growth. It bears large and excellent-quality fruit when cared for properly.
Apple, Jonathan - pruning
WHY To increase apple size
HOW This tree tends to produce lots of small branches that need regular pruning out. Also, you must thin out growing fruit heavily, or the naturally small apples will be even smaller.
Apple, Lobo - pruning
WHY For annual bearing
HOW A large, semispreading, McIntosh-type tree, bearing good-quality fruit that ripens somewhat earlier than regular McIntosh. For annual bearing, prune and thin it if necessary.
Apple, Lodi - pruning
WHY To correct its upright growth habit
WHEN Every other year
HOW This tree produces an apple similar to a Yellow Transparent, but with somewhat firmer fruit. Prune it to correct its upright growth habit, and thin to prevent an overlarge crop every other year.
Apple, McIntosh - pruning
WHY So fruit will need little thinning
HOW This is nearly the ideal tree. If you prune it adequately, the fruit will need little thinning. Although a strong, spreading tree, its limbs may need bracing to support heavy crops.
Apple, Macoun - pruning
HOW The high quality of its apple makes this tree very popular, yet pruning its long, lanky branches is so demanding that many commercial growers have given up planting it. However, it's an excellent choice for a conscientious home gardener. This upright-growing tree tends to bear its small to medium-size fruit biennially.
Apple, Melba - pruning
WHY To discourage biennial bearing.
HOW The high-quality McIntosh fruit of this early-bearing tree tends to ripen over a long season and is good for home use. Prune and thin it to discourage biennial bearing.
Apple, Melrose - pruning
WHY Tends to bear biennially, so thin it heavily.
HOW This large, semiupright tree is a heavy bearer of excellent quality fruits that stay on the tree well. It tends to bear biennially, so thin it heavily.
Apple, Milton - pruning
WHY To keep from bearing biennially.
HOW This tree bears an excellent, medium-size, McIntosh-Yellow Transparent cross. It's ideal for home use. The fruit ripens over a long season, but the tree tends to bear biennially unless it's pruned and thinned.
Apple, Mutsu - pruning
WHY For large fruit.
HOW A semiupright variety from Japan that grows large fruit. It's a heavy producer, yet it seldom weakens itself by overbearing. Thin it heavily for large fruit.
Apple, Northern Spy - pruning
WHY To get largest fruit and insure annual bearing.
HOW This tree produces long-keeping, superior fruit, but it is difficult to prune. It tends to grow very upright, and needs heavy pruning, but unless you do it carefully, you will affect the crop. Thin it to get the largest fruit and to insure annual bearing.
Apple, Prima - pruning
HOW A vigorous, spreading tree that is resistant to scab and other fruit diseases. The fruit is good, and the tree requires ordinary pruning.
Apple, Priscilla - pruning
HOW This is a semispreading tree, resistant to mildew, fire blight, and scab and is an excellent tree for organic gardeners, because it doesn't require much spraying. This tree produces good fruit, and requires ordinary pruning.
Apple, Quinte - pruning
WHY Increase apple size and promote regular bearing.
HOW A semispreading tree, producing an excellent early apple with beautiful color. The tree is not always a heavy bearer, but pruning and thinning will increase the apple size and promote regular bearing.
Apple, Red Astrachan - pruning
WHY So it won't bear biennially.
HOW This semispreading tree produces an excellent, early, old-time apple. It will need regular pruning and heavy thinning, or it will bear biennially.
Apple, Red Duchess - pruning
WHY So won't grow too tall.
HOW Its semispreading shape will benefit from pruning and thinning. It usually needs topping, or it will grow too tall.
Apple, Regent - pruning
HOW This semiupright tree has fruit that usually grows singly instead of in clusters, so it needs less thinning. The high-quality fruit hangs on well. The tree usually bears annually and requires ordinary pruning.
Apple, Rhode Island Greening - pruning
WHY To encourage annual bearing.
HOW The limbs of this very spreading tree will probably need bracing, as fruit loads get heavy. Prune it heavily, and thin the apples to encourage annual bearing.
Apple, Rome Beauty - pruning
WHY To develop a strong tree.
HOW Because Rome Beauty is very upright-growing and rather difficult to prune to a central leader, careful early pruning is necessary to develop a strong tree.
Apple, Spartan - pruning
WHY Bears heavily
HOW This is a large tree with a somewhat semispreading habit of growth. It bears heavily, and needs careful pruning. The tree tends to bear biennially, and the fruit often drops early, and while thinning helps these conditions, the fruit still tends to be small. The quality of the apple, however, is excellent.
Apple, Stayman's Winesap - pruning
WHY Tends to produce long, leggy branches.
HOW Prune back this variety, as it tends to produce long, leggy branches. Be sure to correct any bad growing habits early.
Apple, Twenty Ounce - pruning
WHY To a central leader.
HOW A large, upright-growing tree, best pruned to a central leader and allowed to spread.
Apple, Viking - pruning
WHY So be annual bearer.
HOW This semiupright, hardy tree produces an excellent early apple. Prune and thin it to be an annual bearer. The apple is good for home use.
Apple, Wealthy - pruning
WHY Tends to overbear.
HOW This tree tends to overbear its high-quality fruit on alternate years. Prune and thin it regularly to correct this habit and to prevent the fruit from getting smaller as the tree grows older.
Apple, Winesap - pruning
WHY Prevent weak crotches.
HOW Like the Delicious, Winesap needs careful pruning to prevent it from forming weak crotches. Thin it to allow in sunlight and to increase the size of the fruit.
Apple, Yellow or Golden Delicious - pruning
WHY To correct bad crotches.
HOW The Delicious tends to grow upright and crotchy, with long, leggy branches. Prune it to correct bad crotches and to prevent the limbs from breaking under a heavy load of fruit. Thin heavily for giant-size fruit.
Apple, Yellow Transparent - pruning
WHY This upright grower bears while still young and tends to bear too heavily. Careful pruning and thinning is necessary, or the tree will produce an abundance of small apples and will be short-lived. Be sure to correct bad crotches early so that the branches won't split under the weight of the fruit. This tree is unusually susceptible to sunscald, so white-washing may be necessary to prevent bark injury.
Apple, York Imperial - pruning
WHY To keep top of tree open.
WHEN Late winter preceding the bearing year.
HOW Because this tree tends to bear a large crop every other year, you should prune the fruit spurs heavily in the late winter preceding the bearing year. Thin out small fruits to help even-out yields. Prune to keep the top of the tree open.