Fall and winter lawn care in north Florida | LARRY WILLIAMS

Should I apply a “winterizer” fertilizer to my lawn?
The time to fertilize our warm-season grasses in Florida is during the growing season, not when our lawns are going to “sleep” for the winter. Many so-called winterizer fertilizers can cause more damage than good if they contain too much nitrogen and too little potassium. These fertilizers can cause new tender growth at the wrong time of year, possibly resulting in cold injury to the lawn.

What should I do about winter annual weeds in my lawn?
If your lawn has had a history of winter annual weeds such as henbit, wild geranium, annual bluegrass, chickweed, lawn burweed, etc., you can apply a preemergence herbicide during October. Timing is important when using preemergence herbicides. The herbicide is applied just prior to annual weed seeds germinating. After seedlings are visible, it’s too late to apply the herbicide. Overuse of some preemergence herbicides can result in lawn roots becoming stunted and weak.

Should I overseed my lawn with annual ryegrass?
Overseeding a lawn with ryegrass to create a green lawn during the winter is mostly done for cosmetic reasons. Personally, I don’t overseed because I’m ready to take a break from routine lawn care. I take a break, my mower takes a break and my lawn takes a break. The optimal time to broadcast ryegrass seed is mid October through mid November if you wish to have a winter lawn.

What lawn pests should I watch for during fall and winter?
Fall webworms and armyworms can be active during fall. Your lawn will look like it has been mowed very close when these caterpillars are active. Closer examination of leaf blades will reveal notched leaf edges where caterpillars have chewed.

Large patch fungus (rhizoctonia) is common during the cooler weather of fall, winter and spring. In most cases, this disease results in circular brown areas in the lawn. These circular areas slowly expand, sometimes becoming several feet or larger in diameter. Grass in the center of the circular patches may be green, giving a donut pattern.

Adult mole crickets may be active during fall. Watch for tunneling and areas that feel spongy as you walk in the lawn.

Chinch bugs may continue to be active on St. Augustinegrass, particularly during a dry, warm fall. Look for areas that suddenly turn yellow and then brown within days in the more sunny areas of the lawn.

Fire ants can continue to be active during fall particularly if it is moist.

For specific recommendations on controlling lawn pests, contact your UF/IFAS County Extension Office or log onto http://hort.ufl.edu/yourfloridalawn.

Larry Williams, UF/IFAS Extension Agent, Okaloosa County, September 10, 2014