There are several poplar misconceptions regarding pruning trees and shrubs. Typically professional arborist prune for four reasons:

1. Safety – removal of heavy deadwood is done for the safety of those under a trees canopy. Deadwood is removed over public access areas, homes and wires so that it doesn’t fall and cause property damage or personal injury.

2. Health – proper pruning cuts promote wound closure or less decayed heartwood and ultimately better health. Some pruning practices are also employed to help prevent certain diseases.

3. Improved structure – often called corrective or directional pruning, trained arborist can actually help improve the physical characteristics of a plant with pruning techniques.

4. Improved appearance – since most of our shade and ornamental trees are planted for aesthetic value, professional arborist are trained to prune to improve appearance. For example, many evergreens are pruned to maintain a pyramidal form to improve appearances and maintain low growth for the purpose of privacy.

Pruning generally consists of enhancing a particular trees natural shape and appearance and not trying to create a shape. Pruning a tree to create a shape cannot really be called wrong and this is where the popular misconceptions arise. Creating a shape is a style of pruning known as espaliere, developed at the Palace of Versailles in France but not highly accepted among professionals in America.

Whenever one tries to create a shape in a tree, the tree will in turn grow in an undesired direction, usually up. Always remember that pruning promotes growth, pruning does not retard growth.

Other reasons to prune include:

1. Pruning for more sunlight.

2. Pruning for house and roof clearance. We like to see anywhere from 8-12’ between a trees branches and a house or roof. Too much foliage directly on a building holds in dampness and creates an environment for black ants and termites.

3. Prune to provide clearance on power and telephone lines to help prevent power outages. This type of pruning should only be done by a trained professional. Trained professionals need to be certified to work around energized conductors. As a general rule homeowners are responsible to keep wires clear that run from the street to the house and not wires that run parallel to the road.

Timing is also an important consideration when pruning.

To enhance and maximize flowering, a spring flower tree or shrub should be pruned immediately after the flowers go by and a fall flowering plant should be pruned in late fall or very early spring before new growth starts. In order to force new growth on bare wood for radical size reduction of some evergreen and woody plants pruning should occur in very early spring just before the new growth (March or April).

Timing is also important to prevent the spread of certain diseases especially fungus problems. Never prune plants that are susceptible to fungus diseases of the vascular system when spores are active in the cool damp part of the spring. Examples include dogwood anthracnose, Dutch elm disease, cytospora canker on blue spruce.

Winter is a great time of the year to prune almost all trees especially structural pruning on ornamental trees since the branch structure is more visible without leaves. Winter is also a time when diseases are dormant.

More knowledge about proper tree care is good for homeowners so that they know the difference between the work that professional Massachusetts certified arborists perform and the work performed by untrained professionals. Trained professionals may be more expensive to hire but considerably less expensive than the cost to replace a highly valued plant destroyed by an untrained worker.