Winter requires a different approach to your lawn maintenance schedule. Depending on your climate and type of turf grass, watering may be unnecessary or at least reduced for part or all of the cold season.
Turf grasses are perennial plants and like many trees, shrubs and ornamentals become dormant during winter. Decreasing levels of sunlight, moisture, nutrition, and temperature all contribute to the onset.
For most turf grasses, dormancy begins when daytime temperatures remain consistently below 40 degrees F. Depending on your growing zone, when to winterize your sprinkler system and stop irrigating your lawn could fall anywhere between October and December.
When to Stop Watering Your Lawn For Winter
In USDA hardiness zones 6 and lower, the general rule of thumb is to stop watering when ground freezes which occurs around the third week in November. If your climate is prone to early frosts, such as occurs in higher elevations or low lying valleys, you may need to stop watering at the end of October. When warmer weather persists in areas of hardiness zones 7 and higher, lawns may require water until early December.
During the growing season, most lawns need 1- to 1 1/2 inches of water each week to keep them lush and green. Long, dry spells in areas without much snow cover or winter precipitation may need an occasional supplemental half-inch of water during the off season.
But overwatering can kill the roots of dormant grass leading to bare spots, molds, weeds and pest problems the following spring. As long as temperatures remain below 40 degrees F, there is little benefit to watering and could result in oversaturation and damage.
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6 Signs It’s Time to Stop Watering
Lawn care professionals often advise to reduce watering incrementally as the growing season draws to a close. This can help harden off turf grass which protects roots against harsher weather. Here are signs your lawn is entering dormancy and it’s time to reset your watering schedule for winter.
- Repeated frosts: Overnight frosts for three or more consecutive nights causes turf grasses to start into dormancy.
- Ground freezes: Once ground freezes, water is more apt to sit on the surface instead of penetrating to the roots for any benefit. Irrigating frozen ground can cause oversaturation during freeze/thaw cycles and kill roots.
- Daytime temperatures consistently below 40 degrees F: Cooler temperatures hold moisture with less evaporation which means less supplemental water is needed.
- Grass yellows or turns brown: As days grow shorter and nights longer, color and texture changes in your lawn are a natural occurrence indicating blades are starting to die back to make way for new growth next spring.
- Grass stops growing: If it’s been a while since the lawn required mowing, it’s time to winterize your equipment and start reducing irrigation.
- Soil stays moist: Oversaturation can suffocate grass roots and cause fungi and mold to develop.
Winter Lawn Care Tips
Your lawn won’t require the effort you put in to keep it healthy and pristine during peak growth in spring and summer. But a little maintenance can prevent problems caused by cold weather. Here are tips on how to prepare your lawn and care for it over winter.
- Adjust mower height to cut your grass variety to the appropriate length for overwintering.
- Remove leaves and debris including sticks, pine cones, and grass clippings. As days shorten, you want to give your lawn all the sunlight available.
- Before ground freezes, aerate to loosen thatch and apply a winter fertilizer to give grass crowns and roots plenty of nutrients to keep them viable during dormancy.
- Water thoroughly before frosts to help roots store nutrients for next spring’s growth.
- Check for moisture occasionally during dormancy, especially if you’ve had dry, desiccating winds without snow cover. Use a screwdriver or another long, narrow tool to check for soil moisture. If soil is dry at a depth of 3- to 4-inches the lawn needs water.
- Wait to water for a day when temperatures rise above 40 degrees F. The earlier in the day you can water the better to allow surface drying before nightfall.
- Water with a hose or use a watering can for spotty dry areas. Irrigation systems should be winterized in autumn to prevent damage to pipes.
- Avoid walking on snow or ice covered grass.
- In late winter, inspect for snow mold or other fungi and treat with an appropriate fungicide.
