Fruit Tree Care
Growing your own fruit trees is much simpler than most folks realize. With few exceptions, there are varieties and types of trees that will grow and produce in most any area of North America. Whether you have a tiny lot in the suburbs or 150 acres in the country, there is most likely a fruit tree waiting at the local nursery with your name on it. Even if you live in an apartment with a small patio or terrace, there are miniature versions that will perform well in pots.
While there is nothing complicated about growing fruit trees, there are a few simple things to remember that will help your crop turn out better. Three things I’ll cover in this article are fruit thinning, providing support for fruit-laden limbs, and pruning your trees.
There is hardly a more promising and beautiful sight to a gardener than seeing the limbs of their fruit trees heavy with fruit. Unfortunately, many fruit and nut trees tend to overbear, putting severe strain on the tree as well as lowering the quality of the fruit produced. There is scarcely anything more sickening than coming out in the morning, only to find a limb of developing fruit that was so promising a day before, broken off because of too much fruit on the limb.
As wasteful as it may seem, fruits such as apples, pears, and peaches should be thinned to about 6 or 8 inches between individual fruits. Apricots and Japanese plums should be thinned to 3 or 4 inches between each fruit. Large varieties of plums will do better if the fruit is spaced up to 6 inches apart. The best time to do this is in early summer, when the fruit is between 3/4 and 1 inch in diameter.
Fruit that is not thinned will tend to remain small, develop less sugar, and have poor color. If enough fruit exists, tree limbs will break from the excess weight. The jagged tears and wounds that develop from these broken branches leave easy access for pathogens such as bacteria, viruses, and harmful fungi to enter the plant.
The easiest way for most gardeners to thin their fruit crops is to simply hand-pick the excess fruit from the branches. It may require a little labor, as well as willpower, to “waste” all that fruit. But properly thinned fruit will reduce potential tree damage and yield sweeter, larger fruit.
Many apple trees produce fruit in clusters that contain three to five apples each. These can be a little more delicate to thin down to one or two of the largest apples, but it can be done with care and practice. Small hand shears or large scissors can also be used to cut the stems of the ones you want to remove to avoid accidentally removing the entire cluster.
Trees that are allowed to keep too much fruit often go into “alternate bearing cycles.” Following a year of over-production, the next year’s crop will be very light. This is nature’s way of giving the over-taxed tree time to recover. Proper thinning of the fruit can help avoid these extreme cycles.
The leaves on the trees produce carbohydrates through photosynthesis, which leads to the development of the acids and sugars in the fruit. Leaves also contribute to the size of the fruit when ripe. Known as the “leaf to fruit ratio,” the general rule of thumb is that it takes about 35 to 40 tree leaves to support each developing apple, pear or peach.
Even with proper thinning, fruit can still become very heavy for the branches. Home gardeners and commercial fruit growers alike often wedge long boards at an angle underneath the weighted-down limbs to provide support. Sometimes two boards are used, placed at alternate angles, to support very heavy limbs. Heavy nut crops on younger nut trees often need to be propped, too.
If you see the branches starting to bend under the weight of the fruit, get them propped right away. The strain can break the limb off within a matter of hours. For better positioning, cut a “V’ or curved depression into the end of the board that will be in contact with the limb. Doing this will help hold it in place if it’s windy or if the board or limb is bumped.
Pruning your trees
Many people find the notion of pruning their own trees stressful. They worry and fret that they are going to over prune or destroy their fruit trees. If you fall into this category, relax! Short of sawing off all the branches at the trunk, you probably have very little to worry about. And even if you were to saw them off (not saying that you should), fruit trees are very resilient. Many would simply grow new shoots that would turn into fruit-bearing branches in a few years. Most folks who are new to pruning actually remove too little growth instead of too much. So, take heart! Anyone can learn how to prune.
The reasons for pruning include shaping a strong framework when the tree is young, maintaining the tree at a manageable size, cutting out dead and diseased growth, thinning-out excess growth and crossed-over branches, letting light into the center of the tree for fruit to ripen, and making sure there is not so much fruit-bearing wood that the quality of the individual fruit is impeded.
While some annual pruning is generally necessary, apples, pears, plums, and apricots bear on the older wood and do not usually require as much annual pruning as peaches and nectarines, which bear on shoots that grew the previous summer.
Contrary to popular myth, nectarines are not a cross between peaches and plums. Nectarines are simply peaches that have two recessive genes for fuzzless skin. They are peaches and require the same care and pruning as any other peach tree.
Pruning is done in the winter, when the trees are dormant. In some areas of the West Coast, the South, and the Southeast, this often means January before the buds swell and the sap begins to flow through the cambium, that green layer of tissue underneath the bark. In extremely cold areas, including mountain regions and the northern Plains, winterkill in the trees is a very real problem and pruning is done just before bud-swell, or sometimes just as the buds are starting to swell. Pruning is postponed until this time in these areas to see which branches and shoots survived the winter.
Fire blight is a disease that is deadly to both apples and pears. Cut out any limbs or branches that you notice are infected in the summer as well as winter. Be sure to disinfect your cutting tools with alcohol between cuttings, and dispose of the removed branches. The disease is highly contagious to other apple and pear trees.
A quality pair of sharp, curved-blade pruning shears with long handles and a small pruning saw with larger teeth and slightly curved blade are generally the only tools most people will need for this job.
If you are planting a new, dormant, bare-root fruit tree in late winter or early spring, cut out all but three or four main branches. Choose healthy young branches that will grow outward into a symmetrical circle as the tree develops. These will become your main branches and make up the framework for the mature tree.
As the tree grows and bears fruit, two or more branches growing from the same point on the trunk creates an extremely weak spot. Be sure to trim the branches if more than one is growing from the same spot on the trunk. Choose young branches or shoots that are about 1 foot apart on the trunk. The branches you are going to keep can be pruned back to a shoot that is about 6 or 8 inches long with several buds, or can be taken down to one or two buds near the trunk. For harsh-weather regions, I prefer and recommend the longer shoot, but that is just my preference.
If you are planting a potted tree in the summer or fall and it has a full, mature root ball in the pot, place the undisturbed root ball in the soil and tamp down the dirt to release air pockets and create a water well. Keep the soil moist but not soggy and use mulch to help hold in the soil moisture. Begin pruning the following winter. You can also wait for another season of growth and start pruning the following year. Since these trees are already established, you do not need to cut the branches back as far as you would on a dormant tree.
For second-year pruning, cut out any lateral (upright shoots) growing on the branches or inside the tree. Also remove any “sucker” shoots coming up from the rootstock. Unless it was grown from a seedling, your tree was likely grafted onto seedling rootstock or commercially produced, patented rootstock when it was very young (most fruit trees are grafted). The suckers that come from the rootstock generally produce fruit of very poor quality, if at all, and will compete with the grafted variety of fruit, often resulting in weakness and death of the grafted variety.
As mentioned earlier, apples, pears, apricots, and plums produce on 2-year-old trees or older. Some varieties produce on “spurs,” or short twigs, along the branches that are made up of many fruit buds. These bloom in the spring and produce the fruit. Pruning mature trees can be limited to cutting out excess branches in the center of the tree, removing lateral shoots, diseased or dead wood, and simply keeping the tree at a manageable size for you.
Peaches and nectarines produce on the new shoots that grew the previous summer and require a little more pruning than other fruit trees. Most peaches can only take short bursts of winter temperatures down to 15 or 20 degrees Fahrenheit, and thus cannot be grown in the colder regions of North America. There are some varieties, such as ‘McKay’ and ‘Reliance,’ which can be grown in regions with colder winters, but the geographic regions for these are limited.
Since peaches produce on new, reddish-colored shoots from the previous summer, it is often necessary to cut out older, nonproducing fruitwood from previous years. The older wood that has already born fruit tends to become diseased and harbor pathogens. Remove any tangled, crossing growth. Remove the lateral shoots from inside the tree, as well as suckers from the rootstock.
The new fruit-bearing shoots will grow on each branch. On a standard-sized tree, they will often be 18 to 24 inches long. They must be shortened and thinned-out. If they are not, severe over-production will occur and the tree will be weakened. Since peach trees only have a normal production life of 15 to 20 years, it is important to keep them healthy and strong for as long as possible. Shorten these new, fruit-producing shoots to about 12 inches of new growth, and thin them out to only one shoot every 12 inches, or thereabouts. Peach trees allowed to overbear will have many problems with limb breakage and poor-quality fruit.
Most fruit trees can be purchased in standard size, semi-dwarf and dwarf sizes. Pruning methods for the dwarf varieties may vary slightly from those of standard and semi-dwarf, so check on this when you first purchase them. Many fruit trees will not set fruit if pollinated with their own pollen. These trees need another variety of the same species for cross-pollination. However, there are some varieties that are known as “self-fertile” and will do well as stand-alone trees, since they do not need cross-pollination.
Some varieties of fruit trees are better pollinators than others. ‘Golden Delicious’ and ‘Granny Smith’ apples are known to be high producers of pollen. (Many strains of ‘Golden Delicious’ are also self-fertile.) Both varieties are used commercially as pollinators for other apples. If pollinating insects are present when your trees are blooming, and another variety for cross-pollination is nearby, you will have fruit. Enjoy, and happy eating!
Doug grew up in a family with roots in California’s early fruit industry. He now lives in northwest Minnesota, and has been working for the past 14 years to establish a small apple orchard in the harsh winter climate of the Red River Valley of the North.
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