January 27, 2001
Question: Apparently all this cold weather has affected my St. Augustine grass lawn. There are brown patches everywhere. What should I be doing to get my grass back on the road to recovery?
- Scott, North Fort Myers
Answer: St. Augustinegrass, including Floratam and Palmetto, have a low cold tolerance. In some areas of southwest Florida, it is not possible to have an attractive, green lawn throughout the winter. Injury occurs at low temperatures even in the absence of freeze and frost. Cold damage affects the leaves, runners and roots. If one or more of these essential organ fails, the grass declines leaving whitish-brown to dark brown necrotic areas. These dead areas provide opportunities for the entrance of microbial pests and invasive lawn weeds.
For now, abstain from mowing damaged areas, provide minimal water, do not fertilize, and refrain from fungicide and insecticide applications. Dead or badly injured tissues cannot effectively absorb these inputs and their applications may exacerbate the problem. In February, rising temperatures and increased daylight will trigger St. Augustinegrass from a semi-dormancy state to more active growth. At that time, an application of Ammonium Sulfate and additional irrigation will encourage recovery. For those areas with severe widespread damage, replanting may be the quickest alternative.
- Stephen Brown is a horticulture agent with the Lee County Extension. To submit questions call the horticulture desk at 461- 7504 between 9 a.m. and 4 p.m. or via e-mail at shb@gnv.ifas.ufl.edu. Listen to the ‘Garden Show" at 8 a.m. on 1200-AM WINK/WNOG.