Annual pruning and training of fruit trees is often neglected. Without these two functions, the fruit tree will not develop a strong framework to support good fruit production. The primary purpose of pruning is to establish basic tree structure and channel light. Another goal is to remove broken, dead or diseased limbs.
Pruning is best done in late winter or early spring just before budding. Consider the area where you live to avoid possible winter injury due to extreme cold. Occasional pruning in the summer and fall may be needed, but should be kept to a minimum. Summer pruning should be limited to the current season’s new growth where merely a “trim” is administered. Never cut too much at first. You can always come back.
Basic Tree Structure
In your home garden, no tree will exactly fit the textbook training system. The on-going art work is accomplished by you, the gardener, who has the vision to see its balance of growth and productivity. It’s what is esthetically pleasing to you. Don’t be intimidated by your fruit tree. Remember, that tree is your friend. Take an inviting look at the tree and decide what shape you desire it to be, based on its natural form. Ask yourself, “How can I make it easier to care for the tree?” and “Where do I want it to produce its ripened fruit?” Then, snip here and there ….stand back … take another look … and snip some more.
The main structure of a fruit tree can be shaped like a Christmas-tree, a cone, an umbrella, or teased into a more exotic form. You are the artist and can choose from many different training shapes and forms with multiple variations on each form. Whatever system is chosen, keep in mind the objective to training and pruning is to achieve maximum tree life and productivity.
Establish your tree’s most productive shape in the early years of the fruit tree’s life. Always keep in mind its ultimate size; how large is its natural potential and what limitations do you wish to impose? Maintain the basic shape by annual, dormant-season pruning so each main branch (scaffold) adds enough smaller branches to provide the necessary canopy of leaves for proper photosynthesis (food manufacture). Remove any new branches that grow at odd angles and any old branches that are damaged or diseased. Prune to control overall tree height and harvest ability.
Light penetration through the tree canopy is essential for flower bud development, fruit setting, flavor and quality. In addition, when the tree canopy is more open, adequate air circulates throughout the tree promoting a rapid drying which will minimize disease, infection and fungi.
Training Systems and Tree Forms
The four most common pruning systems for fruit trees are the Central Leader, Open Center, Modified-Central Leader and Trellis (Espalier), although many of the much older trees (80 to 100 years) are clear examples of the Umbrella system.
The Central Leader program adapts well to trees having a naturally upright conformity, such as apples, pears, cherries, prunes and some plums. This is where concentration is focused on that portion of the tree coming straight up from the ground, right out of the trunk and heading skyward. This is the central leader. From this, a Christmas-tree shape (triangle) will be formed with the bottom lateral branches (scaffolds) being the longest, providing the base. The next group of scaffolds will be a little shorter, and the next level up even shorter. This process will continue all the way to the top. Very few scaffolds off the central leader will be needed to support you tree, but you may choose as many as you like.
When using this pruning and training system, be careful to allow yourself enough space under the lowest branches to mow the lawn or easily maintain whatever lies beneath the tree. Always trim the upper branches to maintain the triangular shape and maintain about 60% of the tree’s total volume in the lower scaffold area. This will provide good light throughout the tree and provide ease in tree care and harvesting.
The Open Center or vase system trains the tree to a vase conformation, or internal “U” shape, where no central leader is retained. This does not mean you will have a tree whose entire middle is wide open to the sun. It means that in due time, the primary and secondary branches will add character to your structure and fill in the leafy canopy.
This system is well suited to the stone fruits such as peach, nectarine, apricot, cherry and plum, that have a wide-spreading habit. In this system, the tree’s central shoot, coming up off the trunk, is removed at a point selected by the gardener where the future main branches will be established. Three to five of the branches will be appointed to form the main limbs (scaffolds). This system keeps the center open to sunlight, and when eliminating water sprouts (suckers) that grow straight up from the main limbs, provides good spacing and access to light along each of the scaffold branches. Ideally, scaffolds should be evenly spaced around the tree trunk, but more vigorous branches can be trained to provide this uniformity by using spacers.
As the tree matures, pruning should focus on keeping the center open. Peaches and nectarines bear fruit only on one-year old wood (shoots that grew the previous season), so half or more of each season’s new shoots usually need to be thinned out to prevent crowding. In time, some upper branches on more mature trees will need to be cut back due to dense spreading which will prevent quality fruit production on lower limbs. Consider thinning. Do not heavily prune.
A Modified-Central Leader closely resembles a tree trained in the central leader style and, in fact, is cared for in much the same manner for the first few years. The only difference is that after 4 or 5 main scaffold branches have been selected and trained, it is time to cut the central leader just above the highest scaffold branch opening the tree to further sunlight. Primary and Secondary scaffold branches will gradually fill this area in with new canopy.
The Trellis (Espaliers) system was lavishly described by the scholars in Ancient Greece and Rome where formal gardens and promenades boasted vines and trees of elegant artistry. This more flattened, rather than three-dimensional, sculpturing sprung from the desires of nobility and their need for luxury, but took up much less room, was easy to cultivate and provided an ease by which to gather the fruit. The best fruit trees for this system are apples and pears of the dwarf variety; however, success has been established with cherries, peaches, nectarines, apricots and plums.
Now, anyone can enjoy the creative joy of a tree pruned and trained to resemble a candelabra, rambling grape vine, old-fashion fan, the crisscross of a Scottish plaid, or something much more. Here is where your imagination can go wild!
This system works well any place in the sun where you might consider trellising for roses, clematis, grapes or any other plantings, but it is important to remember, this is a tree and it will need space. The trees should be planted in a North/South direction where both sides of the trellis will receive sunlight for good fruiting. Other directional considerations that include a patio screening, fence or wall should not be excluded, but ideal fruit production may be compromised. Planting too close to a concrete, brick or stone wall should be avoided as reflective heat could burn your trees.
Whether your choice of trellis material is plastic covered wire, wooden posts, bamboo canes or pipe, carefully choose your design and then project the growth pattern so the plants are properly spaced. For instance, if you are looking at purely lateral growth, trees would not be planted as close together as a vertical or crisscross pattern.
It takes a couple of growing seasons to establish your framework; more if you are looking for several branches. After planting, cut the central leader back to a bud just above the lowest trellis wire. Make sure you have at least 2 other buds to accompany it, and let all of these buds sprout. During the 1st year’s growth you will begin the training and pruning of your tiny tree to whatever form you have chosen by using these 3 sprouts. The bottom two will be tied down to form lateral growth or braced at an angle for a crisscross pattern. The third sprout will form the central leader up to the second set of wires where you will repeat the same procedure, on the second set of wires, in the second year. If you have chosen a design other than the traditional lateral branches, these basic first year instructions will help get you started as all designs are formed the same way in the first year.
Umbrella trees are usually older trees planted in yards and small homesteads before the advent of more modern, size-controlling rootstocks. They were pruned in an umbrella shape to keep height to a minimum and produced fruit at reachable levels. These trees have a basic framework of one set of main scaffold limbs which are horizontal and are also the highest, or culminating point of the tree; hence, the name umbrella. In addition, fruit bearing branches grow outward and downward from the main limbs. Many old citrus and avocado trees are good examples of this shape.
The Old, Neglected Tree
Lower the height of the tree. Removal of 4 or 5 feet of growth is acceptable each year. Make the top cut just above one of the outside lateral branches. Take your time. Spreading the cuts over several years will help prevent the tree from shock.
Remove any undesired, large branches from the interior. This will open the center of the tree if not already open. Prune low hanging and crossing branches and remove any dead, diseased or broken branches wherever they exist within the tree.
Head back lateral branches that are too long. Thin carefully. Remove water sprouts and any suckers ascending from the base of the tree. Following annual, moderate pruning procedures will provide the tree with excellent possibilities of good fruit production once again.
Bud – the beginning of a shoot or flower. This could develop into leaves. It may be the extreme end (terminal) portion of a branch or shoot.
Central Leader – the unbranched truck of the tree from the ground level to the point at which the topmost branch arises from it.
Espalier – a wall or framework upon which a tree or other plant may be trained; or, the shape of which a plant is trained to be picturesque as well as productive.
Heading/Headed or Heading back – cutting away a portion of the terminal growth of a branch; it may be an upright branch or one growing laterally.
Open Center tree – a tree trained to a vase conformation. No central leader is retained.
Photosynthesis – food making process occurring in green plant; the chief function of leaves.
Scaffold Branch – one of the branches which is a part of the basic framework of a tree; primary scaffolds are those arising directly from the main truck; secondary scaffolds are the side branches of the primary scaffold branches.
Shoot – vegetative growth produced from a dormant bud; growth developing during a current season. When leaves are gone, it is called a twig.
Spacers – any means by which to more evenly space young tree branches; a clothespin, block of wood, coated wire, rope, etc.
Spur – short shoot or twig which bears flower buds.
Sucker – a rapidly growing shoot arising from the rootstock below the bud or graft union.
Thinning – complete removal of branch either large or small
Water Sprout (loosely, another type of sucker) – a term applied to vigorous, succulent shoots arising indiscriminately and generally on the larger branches of a tree; they are often produced in large numbers just below a pruning cut.