Water Wise Gilbert's Guide to Water Efficient Winter Lawn Care
Fall has finally arrived, bringing cooler temperatures…and dead, brown grass? Don’t worry! Your grass isn’t dead! Cooler temperatures simply make warm-season Bermuda grass go dormant, and no matter how much you water, it won’t grow again until the temperatures rise again next summer. In the meantime, you can enjoy a maintenance-free winter of low water bills, or you can overseed with a cool-season grass and enjoy your lawn all winter.
If you decide to skip the yard work for a season, rest assured the grass will reestablish itself and start growing again around March.
If you would prefer to have a winter lawn, you can start preparing your lawn for overseeding when temperatures are around 55o at night and 82-84o during the day, typically in September or October. Here are some steps to ensure you water efficiently, and enjoy not only an attractive lawn, but also an attractive water bill this winter:
- Sow the seed. Rye grass is applied as a seed into the scalped Bermuda grass lawn at 12-15 pounds of seed per thousand square feet. Consider applying mulch to the top of the soil to help preserve moisture and aid germination.
- Germinate the seed. To successfully germinate the rye seeds, the top one-inch of soil must be kept moist, so be sure to water frequently. We recommend watering four times a day with short bursts (for about two to four minutes, depending on the water application rate of your sprinklers*), until the grass starts to grow. This usually takes about five to seven days.
- Don’t set and forget. Overseeded winter lawns require less water than summer lawns; however, they can often end up using more water if the germination watering schedule is not changed once the grass begins to grow. To prevent this, once the seed is germinated, gradually increase the runtime (minutes) and decrease the frequency (days) of your watering. Make sure you water deeply every time you irrigate—this allows you to go longer in-between irrigation events. Once established, winter rye grass can be watered:
- Once every 3 days in October
- Once every 10 days in November
- Once every 14 days in December and January
- Once every 10 days in February
- Once every 7 days in March
- Cycle and soak. Prevent water from running off onto the sidewalk by utilizing the multiple “start times” on your controller. On the day you irrigate, break up the total minutes you need on irrigation day into 3 different irrigation sessions and run them about an hour apart.
- Stagger your starts. To help reduce the energy demand associated with firing up the water treatment plant pumps when everyone’s sprinklers come on, even numbered houses should water on the top of the hour and odd numbered houses should water on the half hour. For instance, if your house address ends in an odd number, and you need to water for 15 minutes total, you could water for five minutes at 2:30 AM, five minutes at 3:30 AM, and five minutes at 4:30 AM.
- Mow at the right height. We suggest you mow your winter grass at a height of 1.5 to 2 inches. Many times, people think that if they mow lower, they’ll be able to mow less often. The opposite is actually true. A good rule of thumb is to never remove more than one-third of the grass’ height when mowing in order to maintain a healthy photosynthesizing (food-producing) leaf canopy.
For a deeper dive into overseeding, we recommend checking out the following resources from the University of Arizona:
- Overseeding and Transition for Year-Round Turfgrass
- Overseeding Winter Grasses into Bermudagrass Turf
*Water is applied at different rates for spray heads (also called pop ups), rotors, and stream rotors. Know what you have on your system so you can set the proper runtime. Spray heads can apply water as much as two times faster than the other sprinkler types.