Peach, Prunus persica - pruning
Lightly pruned peach trees produce twice as much fruit as heavily pruned trees. Unpruned peach trees will soon stop producing. Peach trees bear only on wood that grew the previous season. This is not true for trees that bear on long-lived spurs.
WHY The flower-buds burst out from existing winter buds of the previous year's new growth, as listed under class II A.An unpruned Peach tree will in a few years have comparatively slender branches almost without foliage, and the little fruit that is produced will be formed only at the extreme ends of the branches.
WHEN The yearling peach tree is generally cut to a whip about three feet high at planting time. With peaches, the cutting back is often carried into one or two year old, or even older wood.
Early spring is best.
The trunk of the tree should be about 18 to 24 inches high; some allow the trunk to be 4 feet high. The lateral branches should be at least 8 inches apart and at good angles, not too narrow. The tree is comparatively shortlived; as soon as the tree fails to respond to pruning and produces poor fruit, the tree should be removed. Thinning out additional fruit is advised after the "June drop," as suggested under Apples. A little summer pruning is also advisable.
HOW In shaping young orchard trees, the main stem is pruned back to make a low head. As the tree matures, the small branches, which have a tendency to grow towards the center of the tree, should be pruned back close to the parent limb to admit sunlight into the open head. These low, umbrella-shaped trees are more easily sprayed, the fruit ripens more readily and is easier to harvest. Apple trees have a tendency to sprout soft young shoots from the side branches. These water sprouts should be pruned close to their base when they appear. If the side branches are very well developed, they may be cut back to two or three buds.
The aim of the pruner is to secure young growth fairly distributed over all parts of the tree, so selected that all parts are in full exposure to light. The entire length of the previous year's growth will burst into flowers, but the best section of the flowering branch is the central 1/3 of the shoot; thus, the pruner definitely aims to cut back 1/3 of all new growth. The method of procedure of pruning the Peach tree is: a. Cut out all dead branches; the older the tree, the greater number of these branches will be present. If the tree is more than 10 years old, it is wise to select new branches from the central framework of the tree to replace old limbs which have become diseased, broken, or too old. b. Remove wood that produced fruit last year; it will not produce again; also cut out crossing or rubbing branches, and branches that do not contribute to the general form of the tree. c. The shape of the tree should be funnel-like, the center being open, permitting sunlight to penetrate all parts of the tree. This aids in ripening the fruit. d. Thin out branches throughout the tree to even its balance, always favor new growth, but if a vigorous branch has exceeded the contour of the tree, cut it back; these elongated branches may snap when loaded with fruit; Peach wood is very brittle. e. Cut back the 1/3 of new growth, always bearing in mind that fruiting branches should be about 1 foot apart over the top of the tree. When the task is done properly, the pruner should have at least 65 percent of the tree on the ground. This is severe pruning, but the Peach tree benefits more by heavy pruning of this nature than any other fruit tree. Even the removal of old wood is a form of rejuvenation of the tree. Often one is forced to cut out as much as 70 to 75 percent of the previous year's growth, but it benefits fruit production in quality and size. A healthy tree will set a large amount of fruit after pruning. During early June the tree will (drop)a portion of its unripe fruit as a reduction process. Varieties that make a late growth may be caught by a frost while their leaves are still immature and the terminal tips of the shoots are still succulent or juicy; these should be cut back at once, removing all of the immature areas injured, cutting back even to 2 to 3 year old wood. By this precaution it may save the tree from becoming badly affected with disease, which often follows the freezing of unripe wood. If this happens, all other pruning should be delayed for a year, so the tree may recover. Heavy pruning of winter or frost injured trees frequently causes the death of the tree.
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.
In cold regions, the Lorette method is risky, since trees pruned in summer tend to keep growing later in the season, and this growth may be injured in the winter. For the same reason, even in areas where the growing season is long, vigorous-growing trees such as the peach and apricot are often difficult to grow by the Lorette method.
The peach has always represented a real challenge to dedicated gardeners. It is fussy about soils and climate, sensitive to spring frosts, and grows so vigorously that much pruning is needed. Yet the juicy, tasty peach is so enticing that even northerners keep trying to grow it.
Those fortunate enough to live where it grows well naturally want to grow it to perfection. Proper pruning plays an important part in peach culture, and an unpruned tree is a sad sight, bearing fruit only at the ends of its branches. Usually both the peach and the nectarine should be grown with an open center. The trees tend to grow fast and late in the season, and pruning makes them grow even faster. In areas where winter damage often kills improperly hardened wood, root pruning may be the only effective way to check excessive limb growth late in the season.
Don't allow peach and nectarine trees to branch closely to the ground, or you won't be able to keep trunk borers under control. Inspect the trunks of the trees frequently, and if you spot a borer's hole, take a wire and dispense with the fat grub at once. Then seal up the hole with either tree sealer, caulking compound, or plastic wood.
Peach, nectarine and apricot trees are likely to grow tall, and since the best fruit often grows at the top of the tree, keep the tops low and accessible. The best method is to cut back the tall-growing limbs each, but if you haven't done this, you can remove the top of the tree during the dormant season with no damage to the tree. However, the fruit crop may be less the following year as the tree recovers from its loss.
The best time to prune is in late winter so that you can cut away wood injured by low temperatures. In years when winter damage is heavy, that pruning may be all the tree can stand. Don't feed the tree after you've had heavy winter damage or after you have pruned it severely, because you don't want to stimulate a rapid regrowth.
Like all fruit trees, peaches often set far too many little fruits, even if you have pruned the tree carefully. As a result, the tree produces a large crop of small peaches. To get large, luscious peaches, thin them when they are about the size of marbles. This may involve a lot of work, because you should space the ones you leave on the tree about seven inches apart, but the results will be well worth your effort.
Even if you faithfully do your pruning and thinning, peach trees have a tendency to set such a heavy crop that broken branches may be a read danger. If this looks likely, you can save your tree by propping up the weighty limbs with wide planks.