How to Winterize Warm-Season Lawns in the Southeast

As the premier grass and sod company in the Southeast, Nimmer Turf recommends preparing your lawn for cooler weather by starting a winterization program in October or November. While warm-season grasses like Bermuda, Zoysia, Centipede, and St. Augustine naturally slow their growth and lose some color in fall and winter, proper care ensures they emerge healthy and green again in spring.

Why Winterizing Matters for Warm-Season Turf

Warm-season turfgrasses respond to environmental signals like shorter days and dropping temperatures by redirecting energy from leaves to roots. While top growth slows, root systems can remain active as long as soil temperatures stay above critical thresholds. 

Applying a fertilizer regimen in fall with higher levels of potassium (K) and lower or minimal nitrogen helps strengthen plants for cold, disease, and other stressors. Potassium contributes significantly to winter hardiness and disease resistance in many warm-season turf species.

A soil test is often recommended for determining existing potassium levels, so you know whether your turf needs supplementation. 

Fall & Winter Lawn Care Tips

1. Mowing

  • Continue mowing as long as the grass is actively growing. Avoid letting warm‐season grass go dormant while overgrown. Give a final cut before dormancy, and clean up leaves and debris. 
  • Use the “one-third rule”: never remove more than one-third of the leaf blade at any mowing. 
  • Recommended mowing heights vary by species. University sources give approximate guidelines:
    • Bermuda: ~1-2” 
    • Zoysia: ~1-2” 
    • St. Augustine: 3.5”+
    • Centipede: 3–3.5”

2. Aeration

  • Core aeration improves soil porosity, reduces compaction, and helps water and nutrients reach roots. Studies show aeration is most effective when grass is actively growing, but fall aeration can still be beneficial if there is enough time before dormancy. 

3. Leaf Removal

  • Fallen leaves left on the lawn can form mats, block light, and trap moisture, increasing risk of fungal disease. Remove them regularly or mulch them to prevent problems. 

4. Fertilization

  • Apply a winterizing fertilizer with a high potassium to nitrogen ratio in mid-to-late fall, before lawns become fully dormant. 
  • Limit or avoid nitrogen late in fall, especially quick-release nitrogen, to reduce risk of disease and winter injury. 

5. Irrigation

  • Even though growth slows, warm-season lawns still benefit from periodic watering in winter, especially during dry, warm, or mild spells. Roots continue to use moisture, and overly dry soil can injure root systems. 
  • Watering should be less frequent than in summer, and always deep enough to moisten root zones. Overwatering under cold or saturated soil conditions can create disease risks. 

The Bottom Line

Winterizing your warm-season lawn with the right mowing height & frequency, potassium-rich, nitrogen-controlled fertilization, leaf removal, appropriate aeration, and thoughtful irrigation is one of the best strategies to ensure a healthy, green spring lawn.

At Nimmer Turf, we provide expert guidance and premium sod varieties to help homeowners across the Southeast maintain healthy lawns in every season. Contact us today for a free sod quote and learn how we can help you achieve lasting curb appeal this winter.