The transition from active growth to winter dormancy requires adjusting your lawn care routine, particularly irrigation. Properly stopping the water supply helps turfgrass prepare for and survive the cold months ahead. This seasonal change allows the grass to slow its metabolism and store energy reserves in its roots. Recognizing both external climatic signals and internal biological cues helps determine the precise time and method for ceasing irrigation.
Seasonal and Climatic Triggers
The decision of when to stop watering is primarily governed by regional weather patterns and the resulting soil temperatures. As the growing season ends, two main environmental factors signal to the grass that it is time to enter dormancy: decreasing air temperature and shorter daylight hours. Turfgrass growth slows dramatically when soil temperatures consistently drop below 50°F, which is a reliable indicator that the plant requires less supplemental water.
A good benchmark for reducing irrigation is when daytime temperatures remain consistently cool, often below 50°F. Cooler air temperatures, especially with repeated overnight frosts, significantly reduce evaporation from the soil surface and transpiration from the grass blades. The lawn’s demand for external moisture plummets. Continued watering at summer levels can lead to oversaturation, which promotes fungal diseases like snow mold and root rot. Timing can vary widely, with northern climates often ceasing irrigation in late October, while warmer regions may continue until late November or early December.
Visual Cues Your Lawn is Ready
Beyond checking the thermometer, your lawn provides clear, observable signs that its active growth phase is concluding. One of the earliest indicators is a noticeable reduction in the grass growth rate, meaning the lawn requires less frequent mowing. The grass is shifting its energy focus from producing new blades to storing carbohydrates in the root system for winter survival.
Another visual cue is a change in the color of the turf, transitioning from a vibrant green to a duller hue, sometimes yellow or bronze, particularly with warm-season grasses. This color change is a natural response to the loss of chlorophyll and is the plant’s way of conserving resources. A practical test is the “footprint test,” where healthy grass blades quickly spring back after being stepped on. When footprints remain visible for an extended period, it indicates a loss of turgor pressure, confirming the lawn’s readiness for dormancy.
The Strategy for Tapering Off
Abruptly stopping all irrigation can stress the root system; therefore, the correct method involves strategically tapering off water application. Initially, decrease the frequency of watering while maintaining the deep soaking pattern established during the summer months. This allows roots to continue reaching deep into the soil for moisture as the ground cools. Instead of the typical one to one-and-a-half inches of water per week, reduce the frequency to a half-inch of deep watering every seven to ten days, depending on natural rainfall.
The final step is the “final deep watering,” which should occur just before the ground is expected to freeze solid or when the lawn is fully dormant. This deep saturation ensures the root zone has a reservoir of moisture to prevent desiccation during the winter months, especially in areas with dry, windy conditions. This application is performed to hydrate the roots one last time before the irrigation system is fully winterized.
Essential Care After Watering Stops
Once the final deep watering is complete and the irrigation system is winterized, attention shifts to other maintenance tasks. Adjusting the final mowing height is important; the last cut of the season should leave the grass slightly taller, around three to four inches. This increased height provides insulation to the crown of the grass plant, offering protection against the cold.
Reducing Foot Traffic
Reducing foot traffic is necessary, particularly on turf that is frozen or covered in frost. Walking on frozen grass blades causes them to snap, damaging the plant tissue and potentially harming the crown, which can lead to dead patches in the spring. Ensuring the lawn is clear of excessive leaf litter and debris prevents the formation of snow mold, a fungus that thrives under matted, moist conditions.