With the freezing this winter, old trees can suffer some damage. To know exactly what damage has occurred, wait for the trees to clear.

Older trees usually require little maintenance. However, a little tender care will extend the life of the tree by several years.

Healing tree problems after they arise is much more difficult, time consuming, and costly than preventing such a problem. Hence, it pays to maintain the tree regularly to ensure that the trees remain healthy throughout their lifespan.

Tree inspection is an assessment tool to alert you to changes in tree health before the problem becomes too serious. During the inspection, examine the features of tree vigor, growth of new leaves or buds, leaf size, branch growth, crown death, as well as damage to insects and diseases.

A decrease in the number of new growing parts like buds and new leaves or the size of the leaves is a pretty reliable indication that the health of the tree has changed recently. Compare the growth of the shoots over the past three years. Has the tree’s typical growth pattern diminished? Was this change caused by climatic factors such as high temperatures, a hard frost, or a drought?

Other signs of poor health can include stem decay and crown death. These symptoms often indicate problems that began as early as the planting years. Loose bark or deformed growths are a common sign of stem decay. New sprouts popping out from under the affected area are a good sign that decay or death has developed in the tree.

The pruning begins when the tree is immature or three to four years after it is established. Pruning mature trees should be done lightly and only when necessary to control the desired shape, remove dead branches, or prevent branches from damaging surrounding structures or people.

Be aware that someone is coming to the door or calling on the phone to “cover” or prune your trees. Especially after a storm, many companies or individuals come out and proclaim themselves “tree experts” because they have a chainsaw. Only use established tree care companies that can provide references.

Fertilization is another important aspect of tree health care. Fertilizer is best used in the fall or spring, although it is not harmful to fertilize it anytime. A good amount of fertilizer is 1 pound of manure per 1,000 square feet under the canopy. If grass grows under trees, apply a slightly heavier dose of the lawn manure. Smaller nutrients are usually not an issue, except maybe zinc on pecans and iron on pen oak.

The main nutrients nitrogen, phosphorus and sometimes potassium are needed in larger quantities. Nitrogen is possibly the most critical of these nutrients. It is the element most responsible for the green growth of the leaves. Since nitrogen is quickly consumed from the soil, it needs to be replenished every year to ensure plant health.

Phosphorus supports root stimulation and is important for flower, fruit and seed production. Fortunately, phosphorus in the soil is not depleted or leached as quickly as nitrogen.

Potassium aids in the production of sugar and starch, aids in the proper maturation of the tissues, and promotes the overall health of the tree. Potassium is usually not deficient in our clay soils, but it can become deficient in sandy soils or in areas with high crop production.

Mulching on the bases of young trees is beneficial, but mature trees receive little benefit due to their extensive root system. Mulches, placed about two to three feet around the trunk of old trees, can be used to keep the weed eaters and lawnmowers away. A summary carefully sprayed around the trunks will also help.

Older trees also need watering, especially in years with little rainfall. Slow heavy pouring from the trunk to the drip line is the best course of action.

Jim Coe lives in Lawton and writes a weekly garden column for The Lawton Constitution.