The American National Standards Institute (ANSI) develops and accredits standards that cover a wide range of topics, including safety, manufacturing, and product distribution. In addition, the ANSI A300 standard outlines practices for properly pruning trees, shrubs, and other woody plants.
How can a homeowner know if an arborist will prune a tree correctly?
“Ask the company representative if their field crews prune according to the American National Standards Institute standard for tree pruning, which is called ANSI A300,” says Jake Allegar, Board certified master arborist & Co-Owner of Cutting Edger Tree Professionals.
The A300 standard recommends, and in some cases requires, that certain tools be used as well as cutting techniques and pruning methods be followed. It sets standard definitions for terms arborists should use in their estimates. Allegar states, “Properly written work estimates for tree pruning should be written in accordance with ANSI A300 standards.”
In addition to the information given in the work estimate, the ANSI A300 sets guidelines for pruning practices that arborists should follow.
Arborists adhering to the ANSI A300 pruning standard will NOT:
- Leave branch stubs
- Make unnecessary heading cuts or top trees
- Cut off the branch collar or make a flush cut
- Lion’s tail trees (removing branches from the inside leaving foliage just at the ends)
- Remove more than 25 percent of a tree’s foliage
- Damage other parts of the tree during pruning
- Use pruning paint/wound dressing (exception: oaks during the growing season)
- Prune without a good reason or objective
- Prune a tree by climbing it with spikes
Pruning Standards
The ANSI A300 pruning standard recommends minimizing the removal of live material to achieve specific objectives. Pruning practices are influenced by tree species, age, condition, and site characteristics, aiming to avoid excessive pruning and large wounds that could harm the tree’s health or structure.
“Pruning is much more than simply sawing off limbs,” says Allegar. “Proper pruning is an art based on scientific principles of plant physiology.” At its most basic level, pruning trees involves removing dead, damaged, or structurally weak limbs, which reduces the chances of personal injury or property damage caused by falling limbs. More advanced pruning methods improve a tree’s structure, provide clearance, minimize storm damage, and improve long-term tree health.
Pruning encourages proper growth, increases flower and fruit production, removes damaged limbs, all while improving the aesthetic appeal of the tree. Pruning the right amount, at the right time, and in the right way is critical, since it is possible to irreversibly damage or even kill a tree through incorrect pruning.
Winter Tree Pruning
According to tree care professionals, winter is an excellent time to prune trees. Why? It is easier to spot potential hazards such as decay, cracks, cavities, and other defects in leafless trees. Additionally, with no leaves on the trees it is much easier to see a tree’s structure and identify potential problems. Structural corrections can be made, especially in young trees, before they become serious problems in the future.
Winter is also an excellent time to prune dead and hazardous branches out of trees. Some homeowners worry that arborists will not be able to identify deadwood in a leafless tree.
“On the contrary,” says Allegar. “In most situations winter is a great time for arborists to locate deadwood by looking for changes in bark color, fungus growth, cracks, and other symptoms that can help them make this determination.
“Most tree species can be pruned year-round, if pruned properly,” says Allegar. “However, certain pruning operations are easier to do in the winter with no leaves on the trees.”
Contact Cutting Edge Tree Professionals. An arborist can assess your trees and work with you to determine the best and safest course of action for any work that needs to be done.
Written by: David R. Jackson, ISA Certified Arborist, Cutting Edge Tree Professionals