For years, gardeners had to contend with dry weather. We are now blessed with rain; however, too much water can lead to root rot.
Many ornamental plant problems that I see are related to poor root growth. The top growth of all plants is directly related to the extent and vigor of the root system.
Soil characteristics determine, to a great extent, how well shrubs, flowers and ornamental trees grow. Physical soil characteristics, such as air and water holding capacity, determine to a large extent the growth and activity of plant roots.
Horticulturists consider an ideal soil to be one in which only about 50 percent of the soil volume is actually composed of soil particles. The remaining 50 percent is composed of pore spaces in between the soil particles. Ideally, about half the pore space would be filled with air and half with water.
As you know most things in life are not ideal. This is especially true with soil in northern Georgia.
In Dawson County most of the soil is heavy clay. Heavy clay soils often hold excessive amounts of water and not enough air.
Professional and amateur gardeners are well aware of the need for water to achieve plant growth.
However, they do not always recognize the problems that are caused by excessive soil moisture. Having heavy clay soils that hold water makes it all the more important not to plant most plants where drainage can be a problem.
Excessive soil water, often associated with disease organisms, kills plant roots leaving the plant unable to absorb adequate quantities of water.
This in turn results in drought symptoms in the leaves, including wilting and browning of the margins or tips of the leaves. Nutrient uptake is reduced and often results in the loss of normal green foliage color. The leaves often turn yellow when excessive water is a problem. This is not to say that whenever leaves turn yellow it is due to too much water, but in the case of heavy clay and excessive rain it very well may be the problem.
Poor drainage is often difficult to correct. Possible remedies include the use of a system of drainage tile at least three feet underground in order to move the water out of the problem area. For tile drainage to work, a lower area must be located nearby for the water to empty into.
Another possible solution to planting in poorly drained areas is to build up the area 10 to12 inches above the surrounding ground level. Existing shrubs must be dug up and replanted at the new ground level if this is done.
One of the most practical approaches in wet areas is the selection of plants tolerant to excessive soil moisture. Ornamentals vary greatly in their tolerance to “wet feet.”
For example, many kinds of hollies will tolerate wet situations that will kill azaleas and camellias.
Ornamentals which have average or above average tolerance to moist soil conditions are: bald cypress, Bradford pear, dwarf yaupon holly, fern species, wax leaf ligustrum, wax myrtle, weeping willow and yaupon holly.
In other news: For the past few years the Dawson Extension Office has hosted a program to certify weight scales. This year scales will be certified by personnel from the Georgia Department of Agriculture from 8:30 to 11 a.m. June 15, at the Dawson Extension Office.
Scale certification is free and required in order for public use of the scale.
Scales may be brought by the extension office during the above times on June 15 or dropped by the extension office before that date and picked up afterwards.
Clark Beusse is the Dawson County extension agent. For more information, call (706) 265-2442.