|By Richard Ashton|
Pruning fruit trees is an art more than a science. There are general rules and methods that need to be observed when it comes down to making a cut, but knowing where to make that cut is an art. Years of pruning will make a person a better pruning artist just by trial and error. A lot of the art is simply standing back and taking a look at the tree and visualizing where the cuts need to be made.
You will be pruning to make a healthy, more productive tree as well as to produce larger fruit. There are many methods of pruning a tree for best health and fruiting, but most fruit trees are pruned to just three tree structures:
Central Leader System. After you plant a young tree, prune the tree back about one-third to account for root disturbance. As the tree grows, let the main trunk grow upward with limbs coming off the main trunk. Limit the branches to the number that produces well for that species. Remember that too many branches will result in smaller fruit.
Prune the branches that come off the main leader so that there is a spacing of at least 8 inches, but no more that 2 feet, between limbs. On very young trees the spacing will be less than 8 inches, but as the tree grows the space will increase. Spacing the branches is where the “art” comes in. You just have to stand back and look at the tree to see where to cut so that the tree has a balanced look.
Crotch angles are important to the central leader system and are discussed below along with pruning because they influence pruning operations.
Open Center System. After you plant a young tree, prune the top back about one-third to help the tree recover from the disturbance of the roots. The nurseries always seem to cut a few roots and the hair roots are mostly destroyed when the trees are barerooted for shipment. When you cut the main leader/trunk, cut it so that the center will remain open. Since this does not happen in one year, you will need to keep cutting the branches back in the center of the tree so that no main trunk develops above where your scaffold branches come off the tree. You will want to select the branches to be saved in a symmetrical pattern. In other words, leave branches as evenly spaced around the tree as possible. Limit the branches to what you think the tree can support and also yield good fruit production. Again, remember, too many branches mean smaller fruit.
Natural. Some fruit species need no training but do need other pruning procedures to maintain a healthy fruitful tree. All fruit trees need to have any dead wood removed on an annual basis. Also, broken limbs need to be pruned off and new spurs need to be developed to replace them.
There are big differences in how you prune different fruit species. Here is how to prune the major fruit species in Texas. The type of pruning system is noted for each species.
Apple — Central leader system. Apples tend to have very narrow crotch angles; the branches come off the tree at an angle that is too upward-growing. These angles need to be increased by spreading the branches. This will cause the tree to have a more spreading look instead of being upright and narrow.
You can use several methods for spreading the branches. Blocks of wood with notches cut in each end will help with spreading. These can be placed in the tree between the main leader and the branches. Wire running from a branch to a tie down on the ground can be used to pull the limbs down to increase the crotch angle. Use padding of some type where the wire is tied around the limb to prevent branch damage. By increasing the crotch angles you will allow more light into the tree for better overall tree health and fruit bearing.
You still need to prune away some of the branches that come off the main leader. Prune so that you have a good spacing between branches. Again, this is where the “art” comes in, and with correct spacing your tree will have a balanced look. Do not leave too many branches as this will result in poor tree health and smaller fruit.
There are spur-type apple trees that have a strong main leader and very short branches. These types of trees produce few branches, so do not remove any limbs. The crotch angles on these trees are usually sufficient without spreading as they are so short.
Apricot — Open center system. Prune young trees to an open center by cutting off the central leader and promoting scaffold-branch growth. You can cut the central leader of a newly purchased young tree about 50 percent of its height. Some people even cut the new tree back to about a foot from the ground to train a tree that can be maintained at a slightly dwarf size. Apricots tend to grow long slender branches. Cut back the branches that have grown out too far to maintain good tree balance. Prune out some of the smaller wood each year to stimulate growth. As apricots bear on 2-year-old fruiting spurs that form on the scaffold branches, you do not want to prune too many of these branches, but you must prune some so that new growth can occur, resulting in new fruiting wood in two years.
Blueberries — Natural. Although blueberries in Texas are normally left to grow as they will, pruning can help. On newly planted blueberry plants cut back the top about one-third to compensate for root damage. When buying plants, it is best to look for good roots rather than big tops. During the first 6 or 7 years, do not prune other than to remove any dead, diseased or crossing wood. After the bush is mature, remove about one-fifth of the limbs at ground level on a yearly basis. This will rejuvenate the bushes for better crops. With the fifth year of mature pruning, you will have a completely rejuvenated bush without sacrificing much production.
Many commercial and ‘pick your own’ operations prune to maintain good shape for easy picking. Keeping the bushes at a good level for picking by removing some of the top on mature trees may be desirable for these operations. But there are mixed opinions on top-pruning.
Cherry — Central leader system. Cherries are vigorous growers and need frequent pruning. They do need some spreading of the limbs as they tend to grow too upright with not enough spreading. Also, spreading the limbs prevents some winter injury. Try to balance the growth of the central leader with the growth of the branches. Each year prune to balance the growth. By cutting back the scaffold branches you will have better shoot growth. The shoots are where the fruiting buds are located, so you want good shoot growth each year.
Be careful when you start spreading the limbs to get better crotch angles. Apply just enough pressure to make the limb spread. Cherry wood is a little more brittle than many other fruit trees and will break if too much pressure is applied.
Citrus — Natural. Citrus trees do not need much pruning, but some is necessary. Semi-annually, prune to remove suckers that grow from the base of the tree. You need to keep removing these suckers or they will take energy from your tree. Many commercial growers also top and hedge mature trees to make for easier picking and maintenance. Hedging means blocking the sides of the trees square with the row like you would any ornamental hedge.
Remove any dead or diseased limbs. Dispose of these removed limbs away from your trees and, if badly diseased, burn the limbs. Citrus diseases can be a real problem. Remove any crossing limbs. Pruning is best done after fruiting and before flowering.
Fig — Natural. Most fig trees are never pruned and produce many figs. But a little pruning can help your fig tree. If you buy a large fig and the roots receive any damage, prune the top back about the same percentage as the roots were damaged. This will help the tree recover from transplanting. As your tree grows, remove any limbs that are growing toward the ground. Also, remove any branches or limbs that are growing too close together.
On mature fig trees you can cut back the tips of the main trunks three to six inches in late winter to produce larger, sweeter figs. Do not try this on young trees as you will restrict their development. Also, remove any dead or diseased wood.
Jujube — Natural. Little or no pruning is needed to maintain a jujube tree. But remove any diseased or dead wood to maintain good tree health. Remove any suckers that come from below ground. Jujubes are nearly always grafted on a wild rootstock so these suckers are detrimental to the tree. Sometimes the suckers will show up 30 or more feet from the tree. Pruning the tree or cutting a root will result in more of these undesirable suckers.
Peach & Nectarine — Open center system. Peaches are one of the most common fruit trees for home growers in Texas. They are also one of the trees that are most commonly incorrectly pruned or not pruned at all by many homeowners. Not pruning will result in a diseased tree that will die within a few years from overproduction of vegetative growth and small fruit.
With peaches and nectarines, heavy pruning in the spring is necessary to get the best crop and have a healthy tree. Peaches bear fruit on year-old wood, so prune for good production. Prune out all hanging branchlets. Hanging means the branch is pointing toward the ground. Prune out any crossing or dead wood. Look at the tree and remember that you want the center open for good light penetration. Because most of the new growth will be in the top of the tree, that is where you will do most of your pruning. Keep the tree at a manageable height. You want the scaffold branches going out and slightly upward. Head-back the scaffold branches each year so they do not get too long.
Pruning out too little wood is the most common mistake in pruning peach trees. If you have trouble determining how much wood to remove in the early spring, wait until the trees are in bloom and prune back where you see too many blooms. You want the fruit no closer than about three inches apart. So prune accordingly. Pruning too much will result in larger fruit so that is really not a problem.
Pear — Central leader system. Pear trees need little pruning but since the branches generally have narrow crotch angles a little spreading of the branches is useful to produce a more spreading tree. When you prune a pear tree, you will see water sprouts (vegetative growth at the cut sites) and the terminal growth increase. Both these things are undesirable. Fireblight is a major problem with a lot of pear varieties and any cuts will increase the chance of blight entering the tree through a cut. Applying a wound dressing to all cuts on a pear tree is necessary to help with healing and fireblight prevention. But you will need to remove any rubbing limbs, water sprouts and damaged or dead wood.
Persimmon — Open center system or Central leader system. Persimmons have been pruned to both these systems with good production. The problem with the open-center system is that when you have a heavy crop, the scaffold limbs tend to break. Though, if you develop strong scaffold branches by training and heading back, you will have a better open-center tree.
The central leader system is probably best for small growers and homeowners. It has the advantage of having a strong framework and being easy to maintain. When planting new trees prune the top back about one-third. If you are going to grow your tree with the central leader system, be sure the central leader is the tallest limb. If another outside limb is taller than the central leader, cut it back below the central leader.
Remove any dead or diseased wood on a yearly basis. In late winter, prune to shape your tree with some heading-back and remove any limbs that are too close together.
Plum and Prune — Open center system. Prune to create an open center on young plum trees. Once you have established the open center with no central leader, you can cut back on your pruning in later years. Prune out small branches, dead and crossing wood annually. Thin limbs throughout the tree to maintain good light penetration. Pruning plums is necessary on an annual basis, but only prune on a limited basis. Plums do not need near as much pruning as peaches.
Pomegranate — Natural with some training. Pomegranates need to be pruned to establish shape when young. Nearly all pomegranates are on their own roots, so any growth from below ground level will be true to variety. Prune to two to three main branches/trunks in most areas of Texas. In Coastal and South Texas, you can grow them as a single trunk tree. Remove any shoots that come from below ground other than the main trunks or trunk.
Pomegranates tend to sucker a lot in the early years and these suckers need to be removed at least twice a year, in late spring and early fall. When the trees get older, top the trees at about 10 feet for easier picking.
Reclaiming Un-pruned Trees. If you have a tree that has never been pruned and you want to establish better orchard practices, start with pruning a little to improve the shape. Do not try to completely reshape the tree in one year. This will result in too many open cuts and could cause the tree to die. Start with a little the first year and complete the shape training in the second or third year.
Tools. Use pruning shears for most pruning jobs. There are several types. Just be sure they make a clean smooth cut and do not just smash or tear the limb off. A fine-tooth tree saw is also necessary for larger limbs. When pruning pears, a wound dressing is necessary, and it is also good to use a wound dressing on apple trees. On any larger limbs measuring more than 1-1/2 inches in diameter also use wound dressing for best healing of the wound.
Time of pruning. Most pruning operations are carried out in late winter. Mid- to late January for South Texas, late January to early February in Central Texas and mid-February in North Texas. Removal of dead or diseased wood can be done at any time.
Richard Ashton is the author of several books on fruit growing, including The Incredible Pomegranate — Plant and Fruit; Jujube — The Chinese Date; Sweet Cherries — For Southern Orchards and Plums of North America. They are all available from Third Millennium Publishing on the internet at www.3mpub.com/ashton