As temperatures drop in Austin, you might notice your grass changing in appearance and growing more slowly.
Does it mean your lawn is in trouble? Nope.
What Is Dormancy?
Dormancy is your grass shifting gears for colder weather. It grows more slowly and may change color, but it’s still alive and needs care to stay healthy. Dormancy is how grass conserves energy and protects itself until warmer air and soil temperatures return.
Important note for Central Texas: the roots are still growing for most of the winter!
What does dormancy look like?
Color Changes:
- St. Augustine: A yellow-brown or patchy appearance.
- Bermuda: A brownish-gray hue that can look dry.
- Zoysia: A golden-brown color, though it often stays greener in mild winters.
What should we do about it?
- Don’t be concerned
- Maintenance – decreased (but not discontinued) mowing and watering with an eye toward leaf and debris clean up.
How Each Grass Type Handles the Cold
1. St. Augustine
St. Augustine thrives in the heat but is less tolerant of colder conditions. When soil temperatures drop below 55°F, it starts to slow down and may develop a yellow or patchy appearance.
Care Tips:
- Water lightly before a frost: If a mild frost is expected (temperatures slightly below freezing for a short time), lightly watering beforehand can help stabilize soil temperatures and insulate the roots. For severe or prolonged freezes, skip watering to avoid freezing damage.
- Keep mowing as needed: Growth will slow, but regular mowing can be helpful. This is why we decrease our mowing schedule in the winter.
- Fertilize as planned: A healthy lawn heading into winter stays more resilient.
2. Bermuda
Bermuda grass is a hardy performer – the cowboy of grasses. When soil temperatures dip below 50°F, it slows its growth significantly, but its deep root system helps it weather the cold.
Care Tips:
- Aerate in the fall: This ensures roots have access to water and nutrients during the cooler months.
- Mow slightly higher before a frost: Taller grass helps shield the soil.
- Don’t fret a brownish-gray color: This is normal for Bermuda in winter and doesn’t mean it’s unhealthy.
- Water smartly before frost: Follow the same guidance as St. Augustine—light watering can help before a short frost, but skip it for severe freezes.
3. Zoysia
Zoysia handles both heat and cold well, making it a favorite for Austin homeowners. It begins to slow down when soil temperatures fall into the mid-50s and can turn a golden-brown color. However, it often stays greener than Bermuda in mild winters.
Care Tips:
- Raking or dethatching is rarely necessary: Only exceptionally healthy and lush Zoysia may need raking to remove excess growth or thatch.
- Water sparingly: Zoysia doesn’t need as much water in cooler months but still benefits from occasional deep watering to maintain root health.
- Keep mowing regularly: Growth slows but doesn’t stop completely, so don’t put away the mower just yet!
How Soil Temperatures and Microclimates Affect Your Lawn
It’s important to note that grass responds to soil temperatures, not just air temperatures. Soil warms and cools more slowly than the air, so even if the weather dips to 40°F overnight, the soil might still be in the 50s. This lag in temperature can delay how quickly your grass enters dormancy or how much it slows down its growth.
Soil temperatures and conditions are also affected by “microclimates”, meaning it gets more/less shade, more/less wind protection, etc. A microclimate can have significant effects on dormancy and winter needs. Ex: full sun but protected from the wind…this area will go into dormancy far later than the area that is in the shade and in a windy area.
Practical Advice for All Grass Types
Protect Against Frost
- Water lightly for mild frosts: Moist soil can retain heat and protect roots during short freezes. However, skip watering if a severe or prolonged freeze is expected.
- Avoid heavy traffic on frosted grass: Brittle blades are more prone to damage under foot.
Keep Up Regular Maintenance
- Even if growth slows, your lawn still needs mowing, watering, and attention to stay healthy through winter. Consistent care makes a big difference when spring rolls around.
Control Weeds
- Cooler months are prime time for weeds to sneak in. Pre-emergent herbicides can help prevent this, keeping your lawn healthy and weed-free.
- When the temperatures drop, your lawn may look different, but it’s still alive and thriving beneath the surface. Understanding how St. Augustine, Bermuda, and Zoysia adapt to cooler weather—and providing them with the right care—will ensure your yard stays healthy all winter long.