An orange construction fence placed in an area with disrupted soil and trees
Construction and other disturbance around trees may cause root injuries that aren’t immediately apparent. Photo by Paul Bachi, University of Kentucky Research and Education Center, Courtesy of UGA Forestry Images.


Heather Kolich, ANR Agent, UGA Extension Forsyth County

July began with three consecutive calls about dying oak trees. In each of the cases, evidence pointed to construction-related injuries to the trees’ root systems that had occurred about a year earlier. The injuries included severed roots, smothered roots from several inches of applied concrete or piled soil, and/ or severe compaction of soil from the weight of heavy equipment. These conditions limited the flow of water and nutrients into the tree, either by removing the root matter that absorbs them, or by reducing the amount of water and oxygen in the soil. Because several of the trees were only affected on one side, they continued on through the fall and entered winter dormancy without showing much indication of injury.

Typically, established trees die slowly, showing signs of decline over a period of two or three years. During that time, we would expect to see branches dying on the side of the tree where the roots were damaged. Drought stress from the spring, however, probably accelerated the demise of the trees.


Weeds are actually the most economically damaging pest. Herbicides, used to control weeds, can also injure desirable plants. Wind, water, and soil translocation can move herbicides from the point of application to surprising distances. If applied at temperatures exceeding 85 degrees Fahrenheit, herbicides can volatilize, becoming an airborne gas. Plants hit by herbicide-laced wind may be killed, or may suffer sub-lethal injuries that show up as leaf scorch or deformities in new growth.

a tomato plant with curled small leaves
Tomato plants are very susceptible to herbicide damage. Parallel veins and clubbed leaves are characteristic of 2,4-D injury Photo by H.N. Kolich.

Some plants are more susceptible to herbicide injury than others. Tomatoes are garden tattle-tales. Tomatoes and peppers in three container plantings in my yard showed signs of herbicide damage shortly after I transplanted them. I was curious to see if the plants could outgrow the injury. I pruned out the misshapen growth and waited to see how the plant would fill back in. The second grow-out was even more malformed, with parallel leaf veins and clubbed leaves characteristic of 2,4-D damage, an herbicide common in many lawn and pasture weed products.

Next, I wanted to test whether the herbicide contact came through the air, or if it was, perhaps, present in the compost I used to make the potting mix. So, I pulled out the injured tomato plants and replanted one pot with a tomato cutting that I rooted from a healthy plant. The plant has recovered from its transplant shock, but the new growth is still too small to reveal any answers.

We have two seasons of annual weeds to combat: summer and winter. Prevention is the best control for weeds. Keep weeds from flowering – and producing more weeds seeds – by pulling them out early or keeping them mowed low in the lawn. Apply pre-emergent herbicides to lawns in late August through mid-September to keep winter annual weed seeds, lurking in the soil from last winter, from germinating and growing into weeds this winter. Pre-emergent herbicides only work on seeds, but when applied at the right time, they continue suppressing seed germination for several weeks.

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