Pruning does more than make a tree look good–it’s important to its health. In the case of deciduous fruit trees, trimming well now will give you a good crop.
All fruit trees need proper watering and fertilizing, but the key to goodproduction for deciduous fruit trees may surprise you. How well a tree fruits in the summer depends on how you prune it in January.
This month–while they’re dormant–is the perfect time to prune many summer-bearing fruit trees such as peaches, plums, apples, nectarines and apricots.
“To keep a deciduous fruit tree producing good amounts of high-quality fruit on a consistent basis, it’s important to prune in January,” said James Barry, a consulting arborist in Orange. “Waiting until the tree starts to bud out is not a good idea, because this will disturb the tree’s physiology.”
The main goal of pruning is to renew or preserve fruiting wood–the wood that bears the fruit. Without healthy, well-preserved fruiting wood, a tree isn’t likely to produce well.
Bill Gelling, past president of the Foothill Chapter of the California Rare Fruit Growers, has 55 fruit- bearing trees in his Fullerton yard.He recalls the year he failed to prune an apple tree–and the resulting poor crop.
“The tree grew upright, and there was just a little fruit at the tips of branches,” he said. “When apples aren’t pruned and allowed to grow, they will grow upward and produce too much shade for fruiting. Apple tree branches actually need to be spread out for good fruit production.”
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Citrus trees should not be treated the same way as deciduous fruit trees. The only pruning the citrus generally require is thinning out crossing branches and removing sprouts that develop at the base of the tree.
Many deciduous trees fruit on branches that are a year or more older. For this reason, it’s important to know what you’re doing before you wield the pruning shears. Over-pruning can be just as damaging as under-pruning.
“Some fruit trees have fruiting wood that is 2 to 3 years old,” Gelling said. “If you accidentally cut off those branches, you won’t have fruit again for a few years.”
When you prune a fruit tree back too hard, you force it into a vegetative mode, which may lead to no fruit for a few years, agrees Fullerton consulting arborist Alden Kelley.
“Pruning for fruiting requires striking a balance,” he said. “There’s an art to fruit tree pruning; you need to use logic and intuition and work with each tree according to its individual growth habits and fruit production.”
Age is also a factor. In general, in the first few years, you train a tree for form, Kelley said. When the tree becomes more established, you concentrate on preserving the fruiting wood. *
Don’t be surprised if your pruned fruit tree doesn’t look all that attractive. “Properly pruned fruit trees tend to have a stubby, uneven look,” Barry said. This occurs because most fruit tree pruning involves heading, or cuts to shorten branches. Thinning or removing entire branches isn’t done as much because you could cut off fruiting wood. Instead, you find last year’s fruiting wood and cut branches off above that point.
There are three ways to find fruiting wood, Barry said. One method is to remember where the tree flowered and fruited the year before. (To make things easier next pruning season, in the summer when your tree is flowering or fruiting, take a picture and then refer to it when you’re pruning).
Another way is to look for clusters of buds on branches. When the weather warms up, these clusters will produce flowers and then fruit.The third way is to be familiar with your particular type of tree. For instance, with peach trees, you’re not going to see any flower buds. They will fruit on all 1-year-old wood, so you should concentrate on preserving that. To locate plum fruiting wood, however, you should look for bud clusters.
While pruning, also keep in mind a few basic rules that apply to all trees, Kelley said. When shortening any branch, make sure there is a suitable side branch one-third to one-half its diameter that is moving in the same direction. This branch can take over for the branch you are removing.
Always make sure to cut out crossing branches, which can rub against one another and allow disease to enter a tree.
When removing any branches, make sure not to cut into the branch collar, which is near the trunk. Making a flush cut on the tree will make it susceptible to disease and can cut off the tree’s food and water supply, Kelley said. Always leave a couple of inches of a branch protruding from the main trunk.
Trees that have been neglected and not pruned or pruned incorrectly can be saved, Barry said.
“If you prune a tree slowly in stages over a couple of years and allow it to store energy, you can get a tree to fruit again,” he said.
You should also lightly prune your fruit trees in the summer after they’ve finished fruiting, Barry said. This prevents heavy branches from breaking and gets more light to the tree. Providing the entire tree with ample light is important because summer is the time when fruit trees store energy for fruit production the following winter.
To have a good crop on any deciduous fruit tree, it’s also important to thin when fruit appears. Thin peaches and nectarines eight to 12 inches apart when they are olive size. Apricots and plums should be thinned four to six inches apart. Apples vary, depending on the type.
Here’s how to prune some of the most popular deciduous fruit trees in the winter months:
APPLES Apple trees are the most complex deciduous fruit tree to prune because there are many types and they bear differently, Barry said. Some apple varieties bear fruit on long-term fruit spurs, which are shoots less than an inch long that flower and fruit at the tips. The spurs are on older branches and become part of a tree’s permanent structure. Care must be taken not to rub these spurs off or damage them.
Once apple trees are mature, they don’t need as much pruning as other deciduous trees. What they do need, however, is to have their branches spread out when the tree begins growing upward.
Although spreading the apple tree goes against its natural tendency to grow vertically, it is important for light penetration and fruit production. Once an apple tree is forced to grow in this particular way, it adapts, Barry said.
APRICOTS To find the fruiting wood on apricots, look for small clusters of buds.Older apricot varieties such as royal (Blenheim) were bred for orchard use and fruit all at the same time. They fruit on 1-year-old branches, and there aren’t many of them, so it’s important to preserve most of them. Prune branches just above the buds.
More modern apricot trees tend to be semi-dwarf varieties that produce fruit over a few weeks. This type grows fruit on branches that are up to 2 or 3 years old, so be careful not to remove old fruiting wood when thinning. Modern apricot trees do need a lot of heading, however, because the branches tend to get very long and whiplike. Cut them back just above the fruiting wood.
PEACHES AND NECTARINES Peach and nectarine trees should be pruned similarly.
Peach trees should be pruned the hardest of all deciduous fruit trees, said Barry, who noted that peaches are good trees for beginners to prune.
Peach tree fruiting wood consists of last year’s growth. You do not, however, want to preserve all of this growth, because the tree would be too full for good fruit production. It’s important to create a good balance of fruiting wood, Barry said.
You will find that peach trees have many new shoots growing up and down the older branches. Two-thirds of these shoots should be removed by cutting them off at the base of the older branch. Then shorten the remaining shoots by two-thirds.
PLUMS Most plums fruit on 1- or 2-year-old wood. To find the fruiting wood, look for clusters of buds.
Plum trees in Southern California tend to be of the Japanese variety. They have many suckers, which are sprouts about 18 inches long that grow on older branches. These should be thinned out because they will never be strong enough to support fruit. If allowed to grow, sprouts can fill in the center of the tree and ruin its structure. Keep plum trees opened up by thinning out these sprouts. After you’ve removed sprouts, head back other branches just above the buds. The older a plum tree gets, the more 1-year-old wood should be removed.
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Additional information on pruning citrus and deciduous fruit trees can be found in “How to Prune Fruit Trees,” by R. Sanford Martin (self-published since 1944), which is available at many nurseries.
