Pruning the Peach Tree
Pruning fruit trees can cause the pulse rate to go up, the blood pressure to rise, and the palms to sweat as you plan to prune what appears to be a perfectly healthy tree. We have all seen butchered trees, and heard stories- usually told by wives of their husbands "pruning the tree". A little bookwork is not out of line before you or yours begins the annual ritual. I have a little pocket sized handbook, "How to Prune Fruit Trees", by R. Sanford Martin that has saved the shape, form and fruit production of many trees. It was first printed in 1944, and is now on it's eighteenth edition. At less than $6.00 a copy it is packed with information, and diagrams of various trees and where to prune. The book is very unpretentious with simple straightforward language, and black and white line drawing illustrations. Glitzy it is not- looking much like a farm advisory booklet, the value is in the content and not the cover.
Peach and nectarine trees benefit from rather heavy pruning, and can be pruned in some cases up to 75% of the previous season's wood. A young tree can be trained to have three central leaders- the main stems that arise from the trunk. A double or triple leader peach tree will develop into a strong tree with plenty of vigor and capacity for fruiting as well as strength to carry the fruit to maturity. If the tree is not lending it's self to develop three leaders, or if space is limited, a forked, Y-shaped, two-leader tree is better than a tree with a single leader. A single leader peach tree tends to over grow in the top and begins to thin at the bottom due to shading. A peach tree that can be pruned to an open funnel shape will allow for better light and air penetration to the leaves. When choosing main scaffolding on a young tree, choose limbs that originate at different heights on the tree. Peach trees have rather weak wood and tend to split and break at the crotch especially if all limbs originate from one place off the trunk. On a young tree the first three or four years will be devoted to developing a strong primary and then secondary set of scaffolds. Scaffolding is simply branching and sub-branching. Attempt to prune to the funnel configuration on the tree, favoring outward growing wood to inward on a young tree, and upward growth rather than outward growth on a mature tree. Fruiting occurs on one year old wood- the twigs and stems that grew last summer. On a one year old twig will be several buds, but only the buds that are in the middle one third of the twig are the best ones to produce fruit, although it will flower all along the twig length, cut back one year old stems by one third. This will give you a larger yield and a bigger fruit. Any wood that has already borne fruit should be removed; it will not fruit again. Cut back weak shoots; remove diseased wood, and any criss-crossing limbs. Prune out one-year-old wood from the center the head, keeping the center of the tree open. Peaches have a tendency to grow fruiting wood upward and outward from the main trunk. Prune to counteract this growth pattern, to give an even branch distribution throughout the entire tree. On a mature tree, one-year-old wood should be about a foot apart all over the top of the tree, and at least 60% of the previous years wood will be pruned away. Heavy pruning of peach and nectarine trees will keep fruit production on heavier wood, which is more capable of carrying the weight of a full crop. A good balance of growth and fruiting should be striven for. A summer pruning technique on a fruiting peach tree is to head back upper, outer shoots in late summer to allow sunlight to the lower branches and prevent dieback due to shading. The peach tree will set more fruit than it normally can carry and will drop a large number of immature fruits early on. This is normal and prevents the tree from breaking and sapping it's vigor, usually occurring around June. If the tree is still carrying too much weight in your opinion, the excess can be hand picked after the June drop.
Genetic dwarf peach trees need very little maintenance training to 4 or 5 scaffolds and nothing else.
Spraying to prevent peach leaf curl is imperative on peaches and nectarines. Once the leaf opens, and shows signs of the disease, there is nothing you can do about it until the next dormant season. Spray now with a dormant spray and again, just before the buds break. Peach leaf curl is treated with a copper based spray, and works best if applied with a sticker/ spreader added to the spray mix. Sticker/ spreader is just that- it helps the copper stay stuck to the tree, a big plus in rainy weather, and emulsifies it so it spreads across the surface of the tree bark more evenly. These two are often sold together as a package.
Carol de Maintenon is a member of Garden Writers of America and owner of Benicia Garden & Nursery.
