If you’ve ever trained a puppy to sit or a kitten to use a litter box, you’ve got what it takes to train a tree — patience.
Many gardeners are plant trainers, having successfully caged a tomato, taught beans to climb a pole or convinced peas to swing on a high wire. But a tree trainer has always been viewed as the ultimate gardener, the true master. Pruning branches selectively to create symmetrical shapes as the trees grow is an art, limiting this art form to two dimensions is called espalier.
This isn’t like clicker training your pets — a biscuit for Fido if he jumps through a hoop. Your tree will not be bribed into growing where you insist. Espalier gives you the rewards. Growing fruit trees in an espalier permits all parts of the tree to be exposed to direct sunlight. There is a higher level of flowering, greater fruit production, and better color development on the fruit.
Any tree or shrub that has long, flexible branches is suitable for espalier but must be planted when young and supple. The saying, “You can’t teach an old dog new tricks,” goes double for trees. Older trees are much more difficult to train.
Before planting your tree you should set up the framework which will be the guide for the horizontal and vertical branches. A free-standing trellis can be built by sinking sturdy posts into the ground and running wires between them.
If building the frame against a wall or fence keep it at least six inches away to allow for air circulation. Mark and drill a set of parallel holes 6-10 feet apart horizontally and every 16 inches vertically until you’ve reached a height of about 6 feet. Screw in 8-10 inch heavy-duty eye-bolts, leaving 6 inches protruding. Using twelve or fourteen gauge galvanized wire, loop and wrap it around one bolt, pull it tight and wrap it the same way at the other end.
The easiest form for the beginner to master is the “informal” or “fan” design. Informal espaliers are ideal for cherry, peach and plum that bear fruit on the previous year’s wood. A new set of branches are trained into position each year parallel to last year’s branches. Each spring, the branches that had fruit last summer are removed.
Apple and pear tree are usually trained as T-shapes or one of the many variations of the cordon. A typical cordon looks like a candelabra.
Start with a whip, or unbranched sapling. That way, there’s no existing branch structure to eliminate or retrain. Plant your new tree or shrub at the base of the framework. Dig a hole deep and wide enough to accommodate the roots. For a grafted apple whip, the bud union should be about 2 in. above the soil’s surface. Fill in the hole, making sure not to leave air pockets where the roots could dry out.
Training begins almost immediately. Let three new buds grow, two branches and a vertical leader. Select branches that will grow in the desired direction and pinch off all others. Young trees grow faster in an upward direction, so train the side branches for a first season to a bamboo pole or other light, rigid stake to keep them straight. Use flexible nursery tape, masking tape, sisal rope, or soft twine to avoid injuring the tree. Do not use wire or twist ties that could girdle the branch as it grows. Examine your ties frequently and adjust the tension if you notice binding. In the fall, lower the sticks and branches to the first wire. Tie the branches to the wire and remove the sticks to use again.
Also rub off any flower buds; this permits the tree to direct its energy into vegetative growth until the espalier pattern is complete. If you are bending a branch and it should happen to crack, don’t despair. A partially broken branch that is securely fastened to the frame will usually heal to the point of appearing normal.
When the vertical leader reaches the second wire you repeat the process.
You will need to keep pinching off any buds that insist on growing in an unwanted place. After a time, and repeating this process as higher wires are reached, you will have a full grown tree that is growing flat against the framework. It will take five to seven years for the tree to fill out, blossom and bear fruit.
Roy Horn, the famous lion tamer learned how fast a trainee can turn on you. Once the tree reaches the desired size, keep pruning to limit its growth or it will revert to its wild nature and become very snarly.