With the freeze this winter, mature trees may experience some damage. To know exactly what damage has occured wait until the trees leaves out.
Mature trees usually need little care. A little tender-loving-care however, will extend the life of the tree by several years.
Curing tree problems once they develop is much more difficult, time consuming and more costly than preventing one. Therefore, it is worthwhile to give the tree regular maintenance to ensure the trees stay healthy during its lifetime.
Tree inspection is an evaluative tool to call attention to any change in the tree’s health before the problem becomes too serious. During the inspection, examine the characteristics of tree vigor, new leaves or bud growth, leaf size, twig growth, crown dieback and insect and disease damage.
A reduction in the new growing parts, such as buds and new leaves or in the size of leaves is a fairly reliable clue that tree’s health has recently changed. Compare the growth of shoots over the past three years. Has there been a reduction in the tree’s typical growth pattern? Has this change been caused by climatic factor such as high temperatures, a hard freeze or a drought?
Further signs of poor health can be stem decay and crown dieback. These symptoms often indicate problems that began at planting years. Loose bark or deformed growths are a common sign of stem decay. New sprouts popping out below the affected area are a good sign that decay or dieback has developed in the tree.
Pruning starts when the tree is in the immature stage or three to four years after establishment. Mature tree pruning should be done lightly and only if needed to control the desired shape, remove dead branches or keep branches from harming surrounding structures or people.
Be aware of anyone coming to the door or calling on the phone wanting to “top” or prune your trees. Especially after a storm, many companies or individuals come out and proclaim to be “tree experts” because they have a chain saw. Be sure to only use established tree service companies that can furnish references.
Fertilization is another important aspect of tree health care. Fertilizer is best applied in the fall or early spring, although it is not harmful to fertilize anytime. A good fertilizer rate is 1 pounds of fertilizer per 1000 square feet under the tree canopy. If grass is growing under trees, applying a slightly heavier dose of the lawn fertilizer. Minor nutrients are normally not a problem except maybe zinc on pecans and iron on pin oaks.
The major nutrients, nitrogen, phosphorous and sometimes potassium is needed in larger amounts. Nitrogen is possibly the most critical of these nutrients. It is the element most responsible for the green growth of leaves. Because nitrogen is rapidly depleted from the soil, it must be replenished each year to ensure plant health.
Phosphorus assists in the stimulation of roots and is important in flower, fruit and seed production. Fortunately, phosphorous in the soil is not depleted as rapidly or leaches out like nitrogen.
Potassium assists in the manufacturing of sugar and starches, helps tissue mature properly and promotes general health of the tree. Potassium is usually not deficient in our clay soils, but can become deficient on sandy soils or areas of high plant production.
Mulches around the bases of young trees is beneficial, however, matures trees get little benefit because of their extensive root system. Mulches placed about two to three feet around the trunk of mature trees can be used to keep the weed eaters and lawn mowers away. Roundup carefully sprayed around trunks will help also.
Mature trees need watering too, especially during low rainfall years. Slow heavy watering from the trunk to the dripline is the best practice.
Jim Coe lives in Lawton and writes a weekly garden column for The Lawton Constitution.