Most lawns go dormant in the winter, but that doesn’t mean you should forget about them until the spring. Keeping them alive and healthy requires maintenance during the colder months.
Watering
Winter watering is usually needed only once or twice a month as a supplement to rainfall. The lawn should be watered deeply each time to the grass roots level, about 6 inches (1 inch of water). Water delivered to the grass root cells keeps them from drying out, and insulates them from freezing temperatures. Moisture in the soil adds even more protection.
The following methods can help monitor soil dryness in your yard to assist with proper irrigation scheduling:
- Push an 8-inch screwdriver into the ground. Don’t water if you can push it more than 3 inches into the ground.
- Dig down into the soil 6-8 inches using a shovel or hand trowel. Take a handful of soil and roll it in the palm of your hand. No watering is necessary if the soil rolls easily into a ball.
- Use a soil moisture meter to check different spots in your lawn. Push the long, metallic probe into the soil 6 to 8 inches, and check the dial for a reading of wet, moist, or dry.
Winter Watering Tips
- Only water when the temperature is above 40°F.
- Watch for predicted freezes, and water a day or two before. This gives the water time to penetrate the roots and protect them from the cold.
- Never water when there’s snow or ice on the ground, even if the temperature is above 40°F. Watering can contribute to ice formation, which is harmful to grass.
- Never water when there’s frost on your lawn. The water can turn to ice, destroying grass blades and killing the lawn.
- Prevent runoff from occurring on sidewalks, driveways, and roads, where it can freeze and turn to ice.
- Water around 9:00 a.m. to avoid the cold morning temperatures, and to give the grass time to absorb the moisture before nightfall. Giving the grass time to dry will also prevent fungal disease.
Minimize Lawn Traffic
Avoid walking on dormant grass as much as possible. It damages easily, and takes longer to recover. A weakened and stressed lawn is unable to resist weeds or disease when it re-emerges in the spring.
Also stay off frozen grass. During a freeze, ice crystals form inside the blades. Walking or driving on the frozen blades crushes them, and causes the ice inside to puncture the cell walls. Those damaged blades can turn brown in the spring.
Yard Cleanup
Keep your lawn free of leaves, fallen branches, and other debris. They can suffocate grass by blocking access to nutrients it needs to survive. Wet leaves and other organic material also provide a perfect home for pests, and create a breeding ground for disease.
Other objects, such as toys, lawn furniture, and landscape equipment should be put away for the winter. They’ll create dead spots on the dormant lawn, and in the spring the grass in those areas will be sparse and stunted. Never park vehicles on grass during the winter — they’ll kill the grass.
Winter Mowing
During the winter your dormant grass grows very little when the temperature is below 40°F. But if you have a moderate winter where the temperature goes above 40°F for a number of days, you’ll have to mow your lawn periodically. Don’t mow just before a frost, or when the grass is wet or frozen.
Keep your grass at the maximum height for its type to help insulate the root system from the cold. As recommended by the Texas A&M AgriLife Extension Service, here are the low and high optimum mowing heights for some common warm-season grasses:
Bermuda (common) — 1.5 to 3 inches
Bermuda (hybrid) — 1 to 2.5 inches
Buffalo — 2 to 4 inches
St. Augustine — 2.5 to 4 inches
Zoysia (fine-textured) — 1 to 2 inches
Zoysia (coarse-textured) — 1 to 2.5 inches
Always follow the one-third rule when mowing — only cut off the top one-third of your grass blades. For example, with grass maintained at 2 inches, mow it before it grows over 3 inches high.
Weed Control
During the winter you can find such common broadleaf weeds as lawn burweed, chickweed, dandelion, and henbit in your lawn. A pre-emergent should be applied in September to prevent their growth. You can split pre-emergent applications by dividing the total in half, and applying the second treatment in December or January.
For weeds that have already sprouted above the surface, apply a post-emergent herbicide. Make sure you spot-treat using a herbicide that only kills the weeds and not the grass. Some weed types, such as henbit and chickweed, can easily be hand-pulled if they’re not spread over a wide area.
Repeated lawn mowing will also keep winter weeds under control by preventing them from flowering and producing seeds. In time, this will cut down on their numbers. Use a bag attachment for the mower to catch your grass clippings and weed seed heads.
Fertilizing
Top dressing with compost isn’t recommended when your lawn is dormant during the winter. You run the risk of damaging or killing the grass. Instead, in December or January, add a bio-stimulant with micronutrients. It will increase the lawn’s microbial activity and help to build healthy soil.
Fertilizing too early before spring is more beneficial to cool-season weeds than grass. Grass can’t take advantage of the fertilizer’s macronutrients until it’s actively growing in the spring. Early fertilization also promotes shoot growth at the expense of the root growth needed for a healthy lawn.
To determine the right time to fertilize in the spring, monitor the soil temperature in your area. The soil minimum temperature should be in the 60s, with daytime temperatures consistently in the 70s. You can also consult a soil temperature map for your location.
Overseeding
For those who want a green lawn during the winter, overseed with an annual or perennial cool-season ryegrass. In the spring the ryegrass will die off, making room for the permanent warm-season grass to return.
Usually overseeding is done on a Bermuda lawn, and is not generally recommended for other warm-season grasses. It’s done in the fall from mid-October to early November after the Bermuda grass has gone dormant. If you overseed too early, the ryegrass will be competing for nutrients and sunlight, and may not establish successfully.
Perennial ryegrass is commonly selected over annual ryegrass because it offers a darker green color, better disease and traffic tolerance, and requires less mowing. In comparison, annual ryegrass costs less, germinates faster, and dies out more quickly in the spring to allow the Bermuda grass to establish itself.
An overseeded lawn in the winter requires more maintenance than a dormant lawn. Here are some guidelines for overseeding:
- Before sowing ryegrass seed, mow your permanent grass to its lowest recommended height.
- Sow half the seed in an east-west direction, and the other half in the north-south direction.
- Until the seeds germinate, water lightly at least every other day. Irrigate regularly once the ryegrass is established.
- Mow the established ryegrass to the lowest recommended height for the permanent grass.
- You can apply a high-nitrogen fertilizer midwinter to maintain ryegrass growth and color.
- Post-emergent herbicides can be applied after the ryegrass has been established and mowed a few times.
Call the experts at South Austin Irrigation at (512) 534-7449 or fill out our Service Request form for professional maintenance and repair to your sprinkler system.
