by Clint Waltz, UGA Extension Turfgrass Specialist
Find this blog and more turfgrass resources at http://www.GeorgiaTurf.com/.
It may be an understatement to say summertime rains in Georgia are “variable”! From mid-May through mid-July – nearly 60 days – many areas across the state had minimal rainfall and daily high temperatures above 90° F, leading to droughty conditions for many lawns. Mid-July, rainfall has been plentiful and temperatures have moderated.
In general, warm-season turfgrasses are resilient and can tolerate relatively short periods (i.e. couple weeks) without rainfall or supplemental irrigation while maintaining commercial acceptability. Furthermore, they can rapidly recover following a sufficient rainfall event.
However, coupling a lengthy dry period with high temperatures, zoysiagrass is a species that can struggle to recover once environmental conditions become favorable for growth. Despite the recent abundance of rain for much of the state, the impacts of hot, dry weather in May, June, and July are now being seen on zoysiagrass lawns. The brown and black appearance of spots in lawns is most likely due to drought-induced dead leaves being colonized by saprophytic fungi – lives on dead or decaying organic matter – and not common symptomology of most fungal pathogens.
With the rain, new shoots will eventually emerge from below ground rhizomes and drought stressed spots will green-up. It may take three to four weeks; slow recovery is a characteristic of zoysiagrass. In the meantime, continue to mow at the correct height – 1.5 inches for zoysiagrass – and fertilize as normal. Applying nitrogen to aid in recovery from this injury may cause insect and disease problems to materialize later. If there is anything to consider helping the grass now, a fungicide application (e.g. Heritage, Lexicon, ProStar, etc.) could offer protection to the new shoots as the grass recovers.
Reach out to your county Extension office for help identifying drought symptoms or disease in your turfgrass lawn: https://extension.uga.edu/county-offices.html