Pruning Young Trees
This is a wonderful and thorough guide for managing young trees by Dr. Ed Gilman, Professor Emeritus of Environmental Horticulture at the University of Florida and one of the foremost authorities in tree structure and maintenance.
Pruning young trees is done to correct or prevent structural issues such as bark inclusions and/or codominant leaders. Training a tree to grow away or parallel to obstacles such as homes or roadways is also important. The practices often employed by line-clearing companies such as heading or sheering do not seek to redirect growth in order to solve problems long term. One of the primary goals of pruning should always to be correct or prevent a structural issue. Otherwise, trees are wounded and the possibility of decay is induced for no good reason. In our opinion, the most complete, up-to-date and authoritative pruning sites are:
- Dr. Ed Gilman, Pruning Shade Trees in Landscapes This site by professor emeritus Ed Gilman of the University of Florida Environmental Horticulture Department is a practical compilation of Gilman’s research and that of others who study trees, tree structure, wind effects and tree stability.
- ISA Pruning Young Trees
Basic Pruning for Young Trees
Less pruning is almost always better for the tree’s health than more pruning. Don’t let a tree service make you feel like you are getting your money’s worth by removing more limbs and foliage. Less pruning is better. Here’s why…
- Green leaves are the factories that make food in the form of carbohydrates for the tree. Remove too many leaves and the tree is weakened.
- Carbohydrates manufactured by the leaves are stored in woody tissue in the branches and trunk. When branches are removed, stored carbohydrates are lost and the tree has to make more.Florida Grades and Standards require that a Florida Number 1 grade tree has a single central leader like the tree on the left. The tree on the right is a Florida Number 2 grade tree. Drawing by Dr. Ed Gilman, University of Florida Environmental Horticulture Professor.
- Excessive pruning causes a tree to form water sprouts sometimes called suckers. Water sprouts are often seen as clusters of small twigs and branches that sprout from a pruning cut stub or from the interior portion of larger branches. Sprouts are a way the tree is putting out more leaves as quickly as it can to make more carbohydrates. Unkowleadgeable tree services will offer to come back for a fee to “clean up” those ugly sprouts, which the tree service caused in the first place by excessive pruning
- Young trees should be pruned for structural strength, not esthetics, by eliminating double or triple leaders that will form a weak structure as the tree develops over the years.
- Small, young trees can tolerate more pruning (up to 33%) than older, mature trees, which should not be pruned more than 10% to 20%. Old veteran trees should be pruned even less.