From LSU AgCenter County Agent Barton Joffrion of Terrebonne Parish
Time to get warm-season lawns in shape
Although recent rainfall was followed by cooler temperatures, we still are at the point in the year where we will see the day-time temperatures in the upper 70s to the low 80s. This means that our warm-season lawns will begin growing rapidly. You probably have had to mow once or twice already, so now is the time to fertilize our lawns.
Turf fertilizers with a high first number, low second number and medium last number are preferred unless a soil test shows otherwise. You may start with a complete fertilizer like 13-13-13 if you know your soil phosphorus is low. If you have a Bermuda grass lawn, use 7-8 pounds per 1,000 square feet.
On zoysia or St. Augustine, use 6-7 pounds per 1,000 square feet. On centipede or carpetgrass, use 4 pounds per 1,000 square feet. After this initial application, use just a nitrogen fertilizer at a rate of one-half to 1 pound of pure nitrogen per 1,000 square feet every five to six weeks until midsummer; then go back to the complete fertilizer. Note that on zoysia and centipede lawns, apply nitrogen fertilizer only one more time in midseason. Use only one-half pound of nitrogen per 1,000 square feet for this.
Weed control in lawns
Most post-emergence herbicides should be applied either before or several weeks after first green-up but not during first green-up. We are at the stage where we are in the first two to three weeks after green-up.
Winter broadleaf weeds can be controlled by using liquid “trimec-type” herbicides that contain formulations with three weed killing ingredients, 2,4-D, dicamba, and mecoprop. They can be used on most southern grasses, but read label before applying. Some trade name examples are Bayer Advanced Southern Broadleaf, Ortho Weed B Gon, Spectracide Weed Stop, Trimec and Ferti-lome Weed Free Zone. These products should be used when temperatures are below 85 degrees Fahrenheit. Read and follow label before applying herbicides.
Tomato spotted wilt virus
If you have been growing tomatoes over the past several years, you probably had tomatoes infected with the tomato spotted wilt virus, which can cause plant wilt and spotted fruit.
It is transmitted from an insect called a thrip. These tiny insects, in both the larval and adult forms, end up in places such as deep in the flowers where they are hard to control. If you have had trouble in the past with tomato spotted wilt virus you may have to plant the more resistant tomato spotted wilt virus variety plants. They include Bella Rosa, Amelia, Mountain Glory, Crista, Quincy, BHN640, Muriel or Talageda.
Insecticide sprays may be used to control the thrips, but once a plant is infected, there are no controls to cure the virus.
Upcoming Events
- Bonne Terre Garden Fair – May 2, 2009, 9:00 a.m. – 4:00 p.m. at Southdown Plantation Home. Admission is $3.00 at the gate, Children under 12 free.
- Vegetable Field Day – USDA Sugarcane Experiment Station. Tentative date – Saturday, June 20th, 9:00 a.m. Master Gardeners, USDA personnel and LSU will sponsor a Vegetable Field Day for homeowners. More information forthcoming.
- Master Garden Class – if you are interested in becoming a master gardener, call my office at 985-873-6495 and get your name on the list. We are planning on having the classes in the evening to accommodate working clientele.
Question and Answer
Question- How do I check for spider mites?
Answer - Very difficult to detect with the naked eye. One clue is many tiny punctures on the leaf surface, with a discoloration giving a salt and pepper appearance to the leaf. When there are many you can see a thin webbing. A 10x or 20x magnifying lens will help you see them.
If you have any questions or need more information, please give me a call at 985-873-6495 or you can email Bennett Joffrion or visit our website at www.lsuagcenter.com.