
When trimmed, the glossy privet makes an excellent hedge. Given ample space and time, however, it can also become a 35-foot tree.
Fruit trees must be properly pruned to ensure good health
By Tony Tomeo
In winter it is important to prune dormant trees, particularly fruit trees, before the end of their dormancy. Trees not pruned properly last winter may now experience problems as the weight of developing fruit becomes too heavy for the limbs. Heavily fruited limbs that are not supported may break and compromise the tree's structure.
In such cases, it is best to prune off broken limbs or dress wounds where limbs have torn away from larger limbs. Clean up any splintered wood or torn bark to enhance proper healing. Painting with grafting compound is not necessary. Some minimal pruning may be performed, but only if absolutely necessary. Hard pruning in summer can be just as damaging as breaking limbs.
To prevent limbs from breaking from their fruit's weight, it is best to support them adequately, or to remove excessive fruit. Fruit removal not only minimizes weight, but also lessens demand on the tree's resources. This may be obvious to many who are experienced in growing fruit trees, but it may be less known to inexperienced growers. (I was recently disturbed to hear of classes that teach summer pruning of fruit trees.)
It is important to realize that fruit trees, as most species of plants, are on a tight schedule between spring and autumn. When they break dormancy, they do not tolerate well major disruptions in their schedule.
Trees pruned in winter respond by adjusting their schedules in advance. It is important to realize the importance of winter pruning and why it cannot be completely eliminated from required maintenance.
Before selective breeding, fruit was small and sparse--easily supported by trees. Breeding for maximum productivity has made most fruit trees dependent on maintenance routines. If left to grow, fruit becomes so large and profuse that it cannot be supported.
Summer pruning also leaves interior limbs exposed to full sun, often resulting in sunburn. In time, new foliar growth will provide shade, but it is often too late. Limbs pruned in winter can shade themselves in early spring when days are shorter and sunlight is less intense.
Otherwise, they would produce more resilient or reflective bark, like fig trees. The fig's reflective bark accommodates its habit of splitting apart during summer. During the winter and spring the broken limbs, still attached to the main tree, root into the soil where they land.
Although the tree probably does not miss fruit production, it will likely miss any lost foliage. The tree is always reliant on existing foliage to grow at a constant rate. If too much foliage is removed when the tree is not expecting it, resources must be diverted, resulting in stunted fruit development. Shoot growth may also be stunted. Stems may be shorter, thinner and not fully developed before dormancy.
Because most fruit trees develop floral buds over a complete growing season, stunted growth will not likely bloom or set fruit the following year. It is also likely that terminal buds of weak stems may not sufficiently "blind out" (enclose themselves in weather-resistant bud scales), and may be damaged by cold, damp winter weather.
Tree of the Week: Glossy Privet
"Tree of the week" may be a misnomer for the glossy privet, Ligustrum lucidum, which is actually best used as a formally clipped hedge. They were once commonly used as street trees because they only get as big as their confinement allows. Their roots are gentle on pavement, but their floral frass and fruit drop is not. Unfortunately, the mess is often not a problem until the tree becomes large enough to be an important feature in the landscape.
Privets are tough and survive with minimal irrigation but look better if watered regularly. Healthy, unconfined trees may grow up to 35 feet tall. As a formal hedge, they are very tolerant of shearing and occasional pruning. If used as an informal hedge that is not sheared and allowed to bloom, the flowers are mildly fragrant and attract bees, although many find the fragrance distasteful.
Horticulturist Tony Tomeo can be contacted at 408.358.2574.