With the arrival of winter, you may think you don’t have to water your lawn, but if the root system is to remain healthy and support new growth in the spring, it will need to receive supplemental water throughout the winter months. Your lawn doesn’t need as much water, however, as during the other seasons because it goes dormant in the colder weather.
Watering your lawn in the winter not only benefits your lawn, but it can also save you money for repairs to your irrigation system in the spring. Your system needs to run regularly to keep valves and seals lubricated so they don’t deteriorate.
To help you set winter irrigation run times, there’s a setting on almost every controller called “seasonal adjust” or “water budget”. This setting adjusts your run times by percentage from the baseline level of one hundred percent. For example, if you program a zone for ten minutes and adjust it to seventy percent, the run time would adjust down to seven minutes, and all the other zone run times on that program would be adjusted as well. Some controllers even allow you to pre-program the percentage per month so it automatically adjusts the percentage for you.
Your controller can also work in conjunction with different sensors to help you irrigate more efficiently in the winter, as well as other times of the year.
A rain sensor turns off your irrigation system after a specified amount of rain has fallen, or in some cases, as soon as it starts to rain. It also delays the system from turning on after a specified amount of water is detected. The sensors have to be installed in an unobstructed location (like a fence or roofline) so that rain can fall on the sensor.
A soil moisture sensor is buried about six inches deep in the ground. It takes moisture readings from the soil to determine if the soil is dry enough for the irrigation system to run. If the soil is wet enough, it won’t allow the system to run. You would want more than one sensor in your yard to cover the sunny and shady areas in order to prevent over and under watering.
A freeze sensor prevents your irrigation system from turning on when the temperature reaches a specific degree, usually around forty degrees.
If you don’t have a freeze sensor, don’t water your lawn on the day when a hard freeze is forecast. The water won’t have time to reach the roots and will sit on the surface. Then, if you walk on or drive over a frozen lawn, the grass leaves fracture, rupturing the leaf cells and causing serious damage. You can even kill the turf grass crowns (thick, light colored part of the plant located at soil level where the grass roots and shoots meet), leading to bare spots on your lawn in the spring.
Weather-based smart controllers are another emerging technology to help with irrigation control. These check the weather forecasts daily, if not multiple times a day, to determine if the irrigations system needs to run. Using WiFi, they connect to either a weather station installed at your home, or a near-by station. When the temperature cools down they reduce the watering time, and when it heats up they add time. If it rains, or bad weather is forecast, they can also delay a watering cycle.
Weather-smart controllers take time to set up. You have to enter information about each irrigation station in your yard (e.g. sprinkler head type, amount of light it receives, slope, landscape material). Many of these weather controllers have apps and websites, so you can control your irrigation from your phone, desktop, tablet, or laptop.
Cycle and Soak
Everyone’s lawn is different when it comes to lawn condition, soil type, and slope, and so irrigation run times may differ from your neighbor’s. But there are some basic guidelines that apply for everyone, no matter what time of year. For example, a common mistake with irrigation systems is over watering in a short amount of time. This causes shallow roots, which can lead to thatch accumulation, soil compaction, and weed germination. Shallow roots make your lawn more prone to insect infestations, disease, and damage from heat and cold. To achieve deep roots and healthy grass you need to set up your irrigation system for deep watering with the cycle and soak method.
The cycle and soak method gives your lawn a chance to absorb water, especially with clay soil. This method also prevents water from running onto the sidewalks and into the street.
Simply take the total time for each zone, and divide it into multiple cycles. For example, instead of watering a single zone for fifteen minutes, set your system to run three times at five minutes. Wait thirty to sixty minutes before running the next cycle to allow water to soak into the soil. The first cycle will break the surface tension of the soil and allow the water to penetrate. The second cycle is absorbed even further into the soil, reaching the roots. And the third cycle is absorbed even more, filling the root zone. Sloped areas may need even additional cycles.
Keep mowing your lawn over the winter at the maximum recommended height for that type of grass. Raising your mowing height helps insulate the root system of the grass. Here are the mowing heights for popular grasses in the Austin area:
Augustine – 2 to 2.5 inches
Bermudagrass – 1 to 2 inches
Zoysia – 1.5 to 2.5 inches
Buffalo grass – 2 to 4 inches
In the winter, cool season weeds thrive, such as chickweed, henbit, burweed, and clover. If you only have a few broadleaf weeds, spot-treat them using a herbicide that kills the weeds and not the grass.
However, your lawn may have too many weeds to spot-treat. In this case, continue to mow your lawn throughout the winter at the maximum recommended height. Most common winter weeds can’t survive repeated mowing. Use the bag attachment on your mower to catch any seeds these weeds produced.
If weeds were a problem for you this winter, remember to apply a pre-emergent herbicide application next year in September.
One of the most effective things you can do for your lawn is to keep your sprinkler system in peak operating condition. Call Smart Earth Sprinklers at (512) 694-1147 for the best in repair and maintenance.