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. Why are my azaleas looking bleached out?
Answer. When the upper surface of azalea leaves look bleached-white and start to fall, chances are Azalea Lace Bug is the culprit. Lace bugs use their sucking mouth parts to feed on plant sap leaving white spots on the leaves.
This pest can be confirmed by looking at the underside of leaves for tarry waste spots, white shed skins, or the insect itself, an 1/8-inch-long insect with lace-like wings.
Besides azaleas, there are other lace bugs which cause similar damage on hawthorn, cotoneaster, Japanese quince, rhododendron, and sycamore.
A systemic insecticide will help manage the pest on azalea; larger trees with the pest will recover on their own.
Q. What’s causing my yellow squash to rot?
A. With as much rain as we have had in July, disease organisms that cause rot have been very active. There are two fruit rots that commonly attack squash: Choanephora Fruit Rot and Cottony Leak Rot.
Choanephora begins on the blossom end of the fruit causing the squash to become soft and watery. A large mass of black fuzzy fungal growth will appear that look like thousands of pins sticking out of a pincushion. There are no effective controls for this disease.
Cottony Leak first appears on the part of the squash fruit touching the soil. A water-soaked spot will occur expanding and causing white fungal growth resembling tufts of
Some fungicides are available to help with this issue. A similar disease called Belly Rot occurs on cucumbers where the fruit contacts the soil. That portion becomes sunken and decayed.
Providing a physical barrier to the soil, such as black plastic between the fruit and the soil, can help. Scab is another fruit rot that occurs on squash, cucumber and other cucurbit crops. Small, sunken lesions appear on the fruit covered with an olive-green mass of spores. Fungicides can control this pest.
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.