Winter lawn care for warm-season grasses takes less work, but there are still steps you must take. Giving some care and attention to your dormant lawn will help ensure a healthy spring growth.
Most dormant lawns only need supplemental watering once or twice a month, balanced with any rainfall. Be sure to water deeply to the grass root level, about 6 inches, which takes an application of about 1 inch. You can monitor soil dryness using the following methods:
- A soil moisture meter. It features an easy-to-read dial indicating whether the soil is dry, moist, or wet. It also has a long, metallic probe that is pushed into the soil 6 to 8 inches to get a reading. Make sure to test a few different spots in the yard. Check Austin Water for availability of free soil moisture meters.
- Use a spade or hand trowel to dig down into the soil 6-8 inches. Grab a handful of soil and roll it around in the palm of your hand. If it rolls into a ball easily, you don’t need to water.
- Stick an 8-inch screwdriver into the soil. If you can push it down more than 3 inches, no watering is necessary.
- Connect a soil moisture sensor to your controller.
Tips for Winter Watering
- Water when the temperature is above 40°F.
- Water a day or two before a forecast freeze to allow the water to penetrate the roots and protect them from the cold.
- Don’t water when there’s snow or ice on the ground.
- Water early in the day to give the grass time to absorb it before the temperature drops at night. Watering earlier also gives moisture on the blades time to evaporate, which helps avoid fungal disease.
- Avoid runoff on driveways, sidewalks, and roads, where it can form hazardous ice.
Rake and clean up leaves, branches, and other debris on your lawn that can suffocate the grass. Clear the lawn of all objects, such as toys, logs, lawn furniture, and landscape equipment. If left on the lawn throughout the winter they’ll create dead spots, and the grass in those areas will be stunted and thinner in the spring. Also, don’t park vehicles on the lawn during the winter — the weight will kill the grass underneath the tires.
Minimize Foot Traffic
Avoid repeated foot traffic in the same area, or at least minimize it. Dormant grass is more easily damaged and isn’t able to repair itself quickly. A dormant lawn that’s stressed and weakened will have a more difficult time resisting weeds or disease in the spring.
Stay off frozen grass. When grass freezes, ice crystals form between the leaf cells to protect the cells from damage. Walking on frozen grass pushes these ice crystals into the cells, causing them to puncture the cell walls. In the spring, those damaged leaves can turn brown.
Common broadleaf winter weeds that grow in dormant lawns during the winter include henbit, chickweed, burweed, and clover. To prevent their growth, a pre-emergent herbicide should be applied in September. Split applications can also be used by dividing the total in half and applying the second treatment around December or January.
Once weeds have emerged, however, you need to use a post-emergent herbicide. Spot-treat the weeds with a herbicide that kills only weeds and not the grass. Alternatively, you can easily hand-pull some weed types, like henbit and chickweed.
If your lawn has too many weeds to spot-treat or hand-pull, repeated lawn mowing will keep the weeds from flowering and producing seeds and will cut down their numbers in time. Use a bag attachment on the mower to catch any seeds already produced.
Some experts recommend adding in December or January a bio-stimulant with micro-nutrients to build healthy soil and increase its microbial activity. The results are similar to using a top dressing with compost, but without the risk of damaging or killing your lawn in the winter (you can top dress in the spring when it’s growing)
You don’t want to fertilize too early before the spring. The grass is still in dormancy and won’t be able to take advantage of the nutrients in the fertilizer. Instead, you may be feeding cool-season weeds, giving them an advantage over the grass.
Fertilizing too early also encourages shoot growth rather than root growth, and a lawn needs deep, healthy roots to survive the cold and resist weeds and disease. To determine the correct time to fertilize, keep track of soil temperatures in your area as spring approaches. The soil minimum temperature range should be in the 60s. You can use a soil temperature map to get this information, or if daytime temperatures are consistently in the 70s the soil temperature will be in the right range.
Over the winter your grass will continue to grow when the temperature is above 40°F. You may have to mow your lawn a few times if the winter is moderate. Don’t mow when the grass is frosted or frozen because the crowns get damaged and crushed and may not grow back in the spring.
To help insulate the root system from the cold, keep your grass at the maximum height for its type. Here are the recommended mowing heights for warm-season grasses (a range indicates varietal differences):
Bermuda (common) — 1.5 to 3 inches
Bermuda (hybrid) — 1 to 2.5 inches
Buffalo — 2 inches
St. Augustine — 2.5 to 4 inches
Zoysia (fine-textured) — 1 to 2 inches
Zoysia (coarse-textured) — 1 to 2.5 inches
Never take more than 1/3 of the height when mowing. As an example, to maintain your grass height at 2 inches, you need to mow before it grows over 3 inches high.
If you want a green lawn throughout the winter, and you have Bermuda grass, you can overseed it with an annual or perennial cool-season ryegrass. Fall overseeding with ryegrass is done from mid-October to early November when Bermuda grass should be dormant. Overseeding is not recommended for other warm-season grasses.
An overseeded lawn in the winter requires the same type of maintenance as a permanent lawn during the other seasons:
- Mow the ryegrass to the same height as your Bermuda grass. Annual ryegrass will have to mowed more often than perennial, or it becomes unmanageable.
- Irrigate regularly.
- Apply a high-nitrogen fertilizer midwinter if needed to maintain ryegrass growth and color.
- Apply post-emergent herbicides for weeds after the ryegrass has been established and mowed a few times.
Your sprinkler system is an important investment. Call Smart Earth Sprinklers at (512) 694-1174 or contact us online for all your inspection, repair, and maintenance needs.