Branch training is a horticultural practice involving the intentional manipulation of a tree’s growth direction to achieve a desired form, improve structural integrity, and enhance productivity. This technique is a proactive, long-term commitment that begins when a tree is young and its wood is flexible. Directing the angle and position of a tree’s limbs manages its overall size and shape. The goal is to create a balanced, healthier framework capable of supporting heavy loads of fruit or resisting damage from wind and snow. This guidance utilizes the tree’s natural growth responses to redirect energy from vertical height into lateral expansion.
Understanding Growth Habits
The ability to train a tree branch stems from a fundamental plant process known as apical dominance. This phenomenon is controlled primarily by the hormone auxin, which is produced in the actively growing terminal bud, or the tip of a shoot. Auxin travels downward, effectively suppressing the growth of the lateral buds located below it on the stem. This hormonal control prioritizes vertical growth, which allows the tree to reach sunlight over competing vegetation.
Training techniques work by disrupting this downward flow of auxin. When a branch is bent or positioned horizontally, the auxin collects on the lower side of the limb due to gravity. This uneven distribution reduces the inhibitory effect on the buds on the upper side of the branch, causing them to break dormancy and develop into new shoots or fruiting spurs. Branches must be manipulated when they are young, ideally within their first one to three years of growth, while they are still highly flexible.
Mechanical Methods for Directing Branches
The most direct way to change a branch’s angle is through tying or anchoring, which uses external force to secure the limb in a new position. Soft materials, such as stretchy plant ties, cloth strips, or old pantyhose, are used to loop around the branch without damaging the sensitive bark. The tie is then anchored to a stake, a lower branch, or a support structure to pull the limb down or sideways. Ensure the tie does not girdle the branch by cutting into the bark as the limb expands in diameter.
Spreading is another primary technique, which involves using rigid objects to push branches apart from the central trunk or leader, forcing them into a wider crotch angle. Commercial spreaders are available, but many growers use simple homemade tools like wooden sticks with V-notches cut into both ends for secure placement. This method is effective for encouraging scaffold branches to grow at a desirable angle of 45 to 60 degrees from the trunk, which provides maximum structural strength.
Weighting applies gentle, consistent downward tension to young branches. Small weights, such as partially filled plastic bottles or specialized concrete weights, are hung near the tip of the branch. Even a simple clothespin can redirect a very young shoot horizontally. The weight should only be heavy enough to bring the branch to the desired angle, typically 45 degrees, without causing stress or breakage at its attachment point to the trunk.
Designing Specialized Forms
Espalier is a classic technique where trees are trained to grow flat, or two-dimensionally, against a wall, fence, or trellis. The limbs are meticulously tied to a support system in formal patterns, such as horizontal tiers or candelabras, requiring precise manipulation of young shoots. This method is popular for fruit trees like apples and pears, which readily produce fruiting spurs along horizontal wood.
Cordon
The Cordon method involves training the tree into a single, vertical or angled stem with very short lateral branches, or fruiting spurs, kept close to the main axis. This approach maximizes fruit production in a small linear space by concentrating the tree’s energy into the main leader and its numerous spurs.
Pollarding
The technique of Pollarding involves severe and intentional cutting back of all branches to a set point on the trunk during dormancy. This repeated cutting encourages a dense head of new, annual shoots to sprout from the same point, resulting in a compact, visually striking form.
Maintaining the New Structure
The duration required for a trained branch to permanently adopt its new position depends on the tree species and its growth rate, but usually spans one to three full growing seasons. During this period, the wood matures and lignifies, or hardens, effectively “setting” the new structure. Once the branch is stiff enough to hold the desired position without assistance, all training materials, including ties, spreaders, and weights, must be removed to prevent them from girdling or constricting the expanding trunk or limb.
After the initial training, follow-up pruning is necessary to reinforce the directed growth and maintain the specialized structure. Summer pruning is often employed to suppress overly vigorous, upright growth that might compete with the established form. Annual thinning of new shoots helps direct the tree’s energy toward the permanent scaffold branches and fruiting wood, ensuring that the long-term training effort is preserved.