Prevent tree damage from storms

High winds and heavy rain or snow can wreak havoc with trees. But there is plenty you can do to help your trees survive storms. Start by inspecting each tree in your garden, no matter what its age or apparent condition. Look for structural faults or other signs that indicate the potential for damage. As you survey a tree, look closely at the crown, trunk, limbs, and crotches (where trunk and limbs meet, and where limbs meet). Keep in mind these seven symptoms of trouble.

1. TOO DENSE CROWN. A top-heavy canopy of foliage can act like a sail, catching wind and causing a tree to blow over or limbs to break. To thin foliage, remove at least half the volume of leaves. You can do this yourself if the tree is small. As one arborist says, "You should be able to see light through the tree's canopy."

2. TOO NARROW CROTCH. A narrow crotch could split, breaking the limb. Installing the necessary bolt, bolts, or bolt and cable is a job for a professional (see "Choosing a Caretaker for Trees" below). You can prune off the limb if it isn't too large to handle and if removing it doesn't harm the tree's shape.

3. TOO WIDE CROTCH. An almost horizontal limb could break under the stress of wind and weight of rainwater on foliage. Shorten or remove the limb if it isn't too large to handle, or have a professional install a cable between the limb and the trunk.

4. DEAD OR WEAKENED WOOD. Winds can cause these branches or limbs to break. Prune them off if they are small enough and low enough to handle.

5. CAVITY IN TRUNK. Sooner or later, the structural integrity of the tree may be weakened, increasing the possibility of the tree or limbs falling. Carve out rotted wood; smooth edges of bark. If you find a water-collecting space or complications involving live wood, consult a professional; the cavity may need a drain or foam filling to keep water from collecting.

6. SHALLOW OR WEAK ROOT SYSTEM. Inadequate anchoring in soil makes a tree more susceptible to blowing over. Unfortunately, it's difficult to tell whether a root system is weak. Thin foliage as necessary to reduce the wind's effect. Water deeply and infrequently to encourage deep rooting. Drill holes in the ground 3 inches wide or wider and 24 to 30 inches deep so water will penetrate to deep root zones; fill holes with gravel. If the tree is old, it may be difficult to stimulate better rooting.

7. CLIMBING IVY. Eventually, climbing ivy stems can girdle the trunk of a tree, interfering with the flow of vital fluids. Ivy foliage adds weight and harbors pests, and its roots compete with the tree's roots for soil nutrients and water. You should remove all ivy as far up as you can reach.

RELATED ARTICLE: CHOOSING A CARETAKER FOR TREES

A good arborist offers a wide range of services, including pest and disease control, pruning, bracing, and fertilizing. If the trees in your landscape show signs of stress or disease, an arborist can diagnose the problem and often help correct it.

Since replacing a tree can cost thousands of dollars (to say nothing of its sentimental value), it pays to shop carefully for the right caretaker. Here are a few suggestions to help you find a competent arborist.

* Don't be swayed by door-to-door solicitation. A good reputation is the best indicator of quality work. Talk with neighbors and nurseries to get recommendations. If you have a city arborist, call for referrals.

* Check the person's previous work for yourself. If possible, visit the homes of an arborist's former clients.

* Get at least three estimates. Talking with a variety of candidates will give you a better understanding of the tasks at hand, the capabilities of each individual, and reasonable prices.

* Be wary of arborists who suggest topping trees; this practice is rarely called for and usually does more harm than good.

* Consider credentials. The International Society of Arboriculture (ISA) offers a voluntary certification program. A certified arborist must have at least three years' experience, pass a comprehensive exam, and participate in continuing education. Certification does not guarantee an outstanding arborist, but it does indicate a serious professional. For a list of certified arborists in your area, write to ISA, Box GG, Savoy, IL 61874.

* Licenses and memberships in professional organizations are other positive signs. California, for example, requires anyone doing more than $300 of tree work to have a state contractor's license.

* Select an arborist who is insured and who is willing to offer proof of coverage for personal injury, property damage, and liability.