Editor’s note: Kelly R. Jackson takes questions called into his phone recently at the Christian County Extension Office and answers them in the Garden Corner column.
Question. My tree was hit by a car. What do I do now?
Answer. Cars, mowers, bicycles, deer rubbing antlers — whatever the cause, if it knocks bark off the trunk of a tree then the first step of tree decay has begun. Exposed wood under the bark is more susceptible to airborne bacteria and fungi that can cause decay of the trunk, roots and limbs. But if a tree can compartmentalize or “wall-off” the damage quickly enough, the decay may be held in check. The formation of callus tissue over a wound is the way a tree provides an external barrier to decay. Our job, as the tree owner, is to help the tree develop callus tissue as soon as possible. First, you should consider the relative health of the tree before injury. If there are signs of tree decline such as dead limbs in the canopy, reduced vigor and growth or decay and the presence of mushrooms or conks on the trunk or branches, then your tree is already stressed and its likelihood of recovery is reduced. Also, the size of the wound is an important factor. If bark has been removed from more than half of the circumference of the trunk, the chances of tree death increase. Complete girdling of the trunk will certainly kill the tree. But if the wound is small and fresh, these steps may help you. While the bark and underlying cambium tissue is still moist, carefully press the bark back onto the trunk. Do your best to fit the pieces back into their original positions on the tree. Secure the bark in place with pieces of soft cloth strips tied around the tree. If the bark has already dried out, use a sharp knife to cut away the loose, jagged pieces. Make a clean edge between the vigorous bark and the exposed wood and shape the wound into a vertical ellipse if possible. This process is called tracing the wound. It will be tempting to cover the wound with a wound dressing but don’t do it. Research has shown that wound dressing can slow down the regrowth process. Remember that removing bark tissue is a stress on the tree and trees in stress need extra TLC, that includes watering, even mature trees, in dry spells. Photos of before and after tracing a tree’s wound can be found on our blog page at
Q. Other than potted mums, what else could I use for fall color in the landscape?
A. Few plants have as bright and cherry blooms in such mass as fall mums but if you are looking for something a little different that could be planted once and bloom every fall, maybe consider Asters. Aster, the Latin word for “star” is the perfect description for this Kentucky native that blooms starting in late summer and can continue until heavy frost. In the past, asters have not been heavily used due to their weedy appearance, but with new cultivars now available, all gardeners will be happy with the smaller, mounding growth habits of these new varieties. Asters should be grown in full sun locations, and they will tolerate most soil conditions. They will establish quicker if planted in the spring in a rich amended soil. Then, after the fall bloom and a hard frost, simply cut the stems back to the ground. Varieties to plant include Sky Blue Aster, New England Aster, and Raydon’s Favorite a selection of a native aster that is a great October bloomer.
Kelly R. Jackson is the Christian County Extension Agent for horticulture. He can be reached at 270-886-6328 or visit Christian County Horticulture online at www.christiancountyextension.com.