February 17, 1999

There’s no doubt the most valuable plants in anyone’s landscape are the mature trees. Large stately trees add thousands of dollars to the value of a property. A home owner can purchase a young tree in a container for ten bucks or have a more developed tree with a four inch diameter trunk installed for 300 to 500 dollars or more. But a large stately tree several decades old is irreplaceable, unless you’re Bill Gates. Yet often the same homeowner who carefully plants and tends a young tree in his yard ignores, or worse yet, improperly prunes his mature trees.

I am always amazed when developers take a tract of land, clear off all the trees and shrubs, build homes, and then (maybe) plant a few new trees here and there. Out of guilt, I suspect, they name the new streets after trees.

Other developers buy a wooded area to build homes among the trees. The homes quickly sell to folks who love the trees and the sense of permanence and shelter they provide. Within a few years, however, some trees begin to decline and die because tractors and bulldozers compacted the root zone during construction. Trenchers and tiling machines ripped through the root systems while installing sewers and utility cables. It is almost always the most valued trees, those closest to the home, that are lost.

A tree is its own worst enemy. When we mistreat a small shrub or perennial it dies right away, giving us an opportunity to learn from the experience. But a tree grows in slow motion and will struggle for years to survive an injury. A tree that has been topped, for example, may live for ten or fifteen years before it must be removed for safety reasons. If a tree died soon after injury, we would quickly figure out the connection. All trees can withstand some stress, but when many traumas and injuries occur, it becomes more than the tree can take.

So what can we do to help our old neighborhood companions, the stately oaks and majestic maples? Most of the time we should just leave them alone. Unless a limb or branch is broken, most shade trees are best left to grow naturally.

Keep lawn mowers and string trimmers away from tree trunks. By scarring and cutting through the protective bark, these two machines kill more trees than any insect or disease.

Before you prune a damaged tree, take a little time to learn how to make the cuts correctly. It is very easy to do even more damage by improperly sawing away broken branches and limbs. The local library and the extension office can help you find good advice on tree pruning. Brochures on tree care are available from the International Society of Arboriculture, Box 3129, Champaign, IL 61826. You can visit their website at www.ag.uiuc.edu/isa.

If you are planning to build or remodel on a wooded lot, fence off the root zones of the trees you plan to keep. Unless you plan to be on site during all working hours, a fence is the only way you can be sure your trees will not be injured. Don’t let contractors place tons of brick or piles of soil over the root zones. Don’t allow masons and plasters to dump waste water under the trees.

After the home, mature trees are the most valuable item on your property and well worth the small effort needed to keep them healthy.