Feb. 23, 2008

Albuquerque Journal

BRANCH MANAGERS
Simply attacking your tree with a chain saw is no way to prune — use a little care
By Eric Billingsley, Journal Staff Writer

Pruning overhanging tree branches and scruffy-looking evergreens may seem like an easy task. But trimming trees incorrectly can not only endanger the health of your foliage, it also can put you and your neighbors at risk, according to local arborists.
   
“Often people look at a tree and say it needs to be pruned, but besides removing dead wood they don’t know what pruning is,” says Eric Bishop, a certifi ed arborist and owner of Eric’s Tree Care in Albuquerque. “It’s not about just cutting the tree.”
   
Pruning requires proper technique, timing and safety, arborists say. When in doubt, hire a professional. And homeowners should require contractors to follow national pruning standards and provide proof of insurance and arborist certifi cation.
   
“What we like to tell people about pruning is to think about what you’re doing,” says Bryan Suhr, a certified arborist and supervisor of arboriculture at the University of New Mexico. “At UNM, we look at every tree and come up with a plan.”
   
Randomly trimming branches can injure trees, affect their appearance and kill them. Every cut is a potential entry point for decay. And trees never completely heal a wound, they compartmentalize it, meaning they wall it off to avoid the infection from spreading, according to Bishop.
   
“If you do things wrong, there are consequences,” he says. “Trees in Albuquerque take so long to grow and are precious. But they get mutilated all the time.”
   
Many arborists oppose “topping,” the indiscriminate cutting of branches to stubs, often done to limit the height of a tree. Regrowth is weaker than original branches. Multiple cuts also can weaken trees’ defense mechanisms and lead to decay, sunburn and a reduction in the tree’s food source — leaves from the upper canopy, according to treesaregood.org.
   
“If a tree has been topped, it is much more dangerous from that point forward,” says Suhr, adding that weaker regrowth is also more apt to break and cause property damage and harm to people.
   
Continuously raising the canopy also can do more harm than good, says Bishop. Unless lower branches are creating a safety problem, they may not need to be cut. They can protect a home and property by catching parts of the tree that fall from the canopy.
   
“Our priorities go from keeping people safe and trees healthy to then making them look good,” says Bishop. “Many people think in the complete opposite.”
   
Many arborists abide by tree care guidelines set by the American National Standards Institute. Homeowners can verify whether contractors are certifi ed by the International Society of Arboriculture by visiting the Web site, isa-arbor.com.
   
Homeowners also should ask contractors for proof of insurance, including workers’ compensation, and references before starting the job, according to treesaregood.org.
   
If contractors don’t have workers’ compensation insurance, homeowners may be liable for injuries that occur on their property.
   
Structural tree health and reducing hazards such as trees growing into power lines or near roads or buildings are appropriate reasons to prune, Suhr says. But if those factors don’t exist and a tree is otherwise healthy, it may be best to leave it alone.
   
The time of year to prune varies according to species.
   
Clearing deadwood can be done almost any time. Some trees are better to cut when they are dormant because wounds will heal faster in the spring. But trimming fully matured leaves in late summer may be better for slowing growth. Certain times of the year are also more prone to insect infestations. Each tree needs to be reviewed, Suhr says.
   
When a tree grows close to power lines, homeowners shouldn’t trim it themselves, he says. Power companies have crews trained to deal with the problem. And never use power tools or sharp equipment while climbing a ladder.
   
“Every above-ground line has the potential to kill, and green wood is an excellent conductor of electricity,” says Suhr. “Don’t use a chain saw unless you’re properly trained. Working from a ladder with a chain saw is one of those things that’s unforgiving.”
   
Homeowners often fail to remember root health, too, says Bishop.
   
It’s a myth that root systems mirror the canopy, he says. They can grow to be two to three times the size of the canopy, and most are within the first 2 feet of soil.
   
Homeowners need to be careful not to damage or cut off a root’s access to water when digging, rototilling or landscaping.
   
In the end, trees grow best when mostly undisturbed, says Bishop. “Pruning and treatments should be more frequent and subtle,” he says. “Mostly what kills trees are people.”