Lawn and Garden Questions
The weather feels like it is getting back to normal this week. Although this week has been cold, the warm wet weather has kept many plants from going dormant. The warm weather has also prompted a few more calls than usual during this time of year to the Caldwell Extension Center. I thought I would share two questions that would be of general interest.
What is wrong with my lawn? There are dead spots in my lawn.
I made a house call to figure this one out. Some plant diseases are so unique they can be identified from the car windshield. Red thread is a turf disease. The name, red thread, is an excellent description of this disease, too. The red, or pinkish, fungal mycelium (or threads) make this disease’s name very descriptive.
However, plant diseases don’t just happen. There are three things that must occur for red thread, or any disease, to develop. The disease causing organism must be present, there must be a susceptible host plant, and environmental conditions have to allow for the disease organism to grow. If one of these factors is missing, the disease will not develop.
For red thread to develop, the fungus, Laetisaria fuciformis, must be present. And there must be an acceptable host. Acceptable host plants for red thread are chewings fescue, tall fescue, kentucky bluegrass, ryegrass, and bermudagrass. The environmental conditions also have to be support the disease organism’s growth. If one of these factors is missing, the disease can not grow or develop.
Though red thread rarely kills its host plant, it does weaken the grass stand. It also makes the turf look unhealthy. Red thread develops in the spring and fall when the weather is cool and wet. This is the type of weather we have had since October. The disease occurs when the grass is growing slow because of overcast weather and the turf fertilization is unbalanced.
If this disease shows up in your lawn, it is a good indication your fertility program needs to be examined. Take a soil test. Be sure you are getting enough nitrogen on the lawn in February, September and October. You can remember these dates as Valentines Day, Labor Day, and Halloween. Besides getting enough nitrogen, ½ to 1 pound of nitrogen per 1,000 square feet, be sure there is enough potash for a healthy lawn, too. For additional information, consult the NC State Turffiles Tall Fescue Maintenance Calendar. This publication is available online or by calling the Caldwell Extension Center at 757-1290.
What is this on my camellia?
Camellias are often attached by scale insects. Scale insects feed on plants by piercing plant tissue and sucking sap. Scales do not look like typical insects. They are small, immobile, and have no visible legs. They vary in appearance depending on species and gender. Some look like small fish scales attached to the plant. Because of their unusual appearance, these insects can reach damaging levels before they are noticed.
Tea scale is the most common insect pest on camellias. Their feeding weakens the plant and causes yellow splotches on the upper surface of leaves.
With a large infestation, the undersides of the leaves are covered by a cottony mass.
Some scale infestation can be handled by hand picking the infested leaves. Bigger infections need pesticides to tackle the problem. Horticultural oil can be sprayed to control the crawlers and keep them from becoming adults. Do this in the spring, after the plants have finished blooming and the danger of cold weather has passed. With tea scale, crawler activity coincides with the flush of new plant growth in the spring. Timing is important when using horticultural oils. Also, be sure to completely cover the plant, including the underside of the leaves. This is a contact product. If the crawlers are not contacted by the spray application, they will not be controlled. If using horticultural oils, plan to make two spray applications, 10 days apart.
A soil applied insecticide can be used to control the adults as well as immature crawlers. This can be done once early in the spring. Treat around the base of the infested plant with a product containing dinotefuran. However, products such as Safari that contain dinotefuran are not packaged for homeowners. As with all pesticides, read and follow all label instructions and precautions.
For answers to your agricultural questions, call the Caldwell County Extension Center at 828-757-1290 or visit us online anytime at https://caldwell.ces.ncsu.edu.