Diagnosing Fungal Issues in New St. Augustine Sod

Circular yellow patches with easily pulled blades, black decay at the base, mushrooms, and white crystals on blades in Orlando St. Augustine sod point to fungal disease—likely dollar spot or brown patch—fueled by excessive rain and overwatering.

Stop all irrigation immediately. Let the grass dry until it shows drought stress. Do not fertilize—nitrogen feeds fungal growth. Once dry, resume deep, infrequent watering. Most affected areas will recover; dead patches may need re-sodding.

Scotts SummerGuard (insecticide + fertilizer) and Scotts fungicide applications may have complicated the picture. The insecticide was unnecessary if chinch bugs weren't confirmed (tin-can test was negative). The fungicide helps but cultural correction—drying out—is primary.

Sharpen mower blades. Mow at 3.5–4 inches for St. Augustine. Avoid afternoon watering. Get a soil test through UF/IFAS Extension for long-term management.