You may have already heard a rumble or two of thunder this year, and the odds of a damaging storm will only increase as summer approaches. In addition to the possibility of severe thunderstorms, the Atlantic hurricane season begins on June 1 and will last through the end of November.

If your trees are vulnerable to the strong winds these storms produce, branches or even the entire trunk may come crashing down on your home, vehicles, or garden. Working to prepare your trees during the milder spring weather can save you this hardship later in the year.

Though the trees on most properties have been around for many years, you'll want to keep summer storms in mind if you are planting any new ones. The University of Florida Institute of Food and Agricultural Sciences says larger trees should be planted a safe distance from your home, power lines, or anything else you wouldn't want to see damaged if the tree or branches fell.

Some trees will be able to endure wind better than others. Look for trees which are known for wind tolerance. The Virginia Department of Forestry says some species include the baldycypress, black gum, sweet gum, and white oak. Planting the trees in groups can create better resistance to the wind.

Certain conditions will increase a tree's vulnerability. Roots may have been damaged if a lot has been cleared recently, and winds can uproot a tree more easily if it is in loose soil.

Inspect the trees on your property to see if any of them have signs of weakness. Problems may include damage caused by a lawn mower or other item colliding with the trunk; rot in the branches, stems, or roots; lopsided trees; or treetops with many twigs or small branches.

The last condition is known as "topping." The University of Florida says this condition is created when most or all of the leaves are removed from branches. In addition to creating a sail effect and increasing the possibility of wind damage, this kind of pruning also makes the tree more vulnerable to rot.

Some pruning is necessary to improve wind tolerance, however. Davey Tree, an Ohio-based arborist service, says wind can easily damage the branches and trunk of a tree when there is a thick canopy. Pruning the canopy allows for the removal of dead branches and also creates more space for wind to pass through.

The University of Florida says it is not necessary to thin the canopy every year, but that this process should be done when it becomes difficult to see through the top part of the tree. Removing about 25 to 30 percent of the foliage, including some internal branches, is sufficient; the lower part of the tree should retain about two-thirds of its foliage.

The University of Florida says other improper pruning methods include "liontailing" and "uplifting." The former prunes all but a tuft of leaves at the end of a branch, while the latter removes only the lower branches. Both methods make it more likely that the tree will be damaged by storms or disease.

Larger branches are more likely to withstand strong winds. Avoid removing limbs with a diameter of two inches or more unless they are presenting a hazard, since cutting them leaves a larger wound and increases the possibility that the tree will suffer from disease. However, the Virginia Department of Forestry says a tree will be most stable if the thickness of a branch is not more than half to three-quarters of the trunk's diameter.

Limbs are strongest if they are growing from the tree at a 45-degree angle or greater. Those which grow parallel to the trunk are more vulnerable to breaking away. If two branches are rubbing together, remove one of them; otherwise, the contact can open a wound and cause the tree to be affected by disease.

Avoid digging around the base of the tree. If you strike a root, it can weaken the tree and make it more vulnerable during a storm.

Trees with noticeable splits, large cavities, or severe root damage are the least likely to survive a storm. You may have to consider removing these trees to prevent them from causing damage.

Davey Tree says one simple method of keeping a tree in good health is to keep a layer of mulch around the base of the tree. In addition to keeping the lawn mower from damaging the trunk, it also helps bring water and nutrients to the tree.

A more complex option for protecting your trees seeks to avoid lightning damage. An arborist can set up a series of wires or even a lightning rod to direct the bolt's energy into the ground.

The Virginia Department of Forestry recommends that homeowners looking for an arborist should make sure the company is certified and has the necessary insurance and workers' compensation. The department also suggests getting an estimate that outlines all work and costs, asking for references, and paying when the work is completed rather than up front.