As one of the most common lawn grasses, fescue is often grown alone or mixed in with other grass seed varieties in general lawn mixes. Fescue remains green during cooler weather, only dying off during the heat of summer or the bitter cold of winter. Zoysia, on the other hand, thrives during long, hot summer days, only going dormant in response to cooler fall and winter temperatures. A lawn containing both fescue and zoysia will remain green year round in areas that don’t experience freezing, or will only brown during winter in colder climates, as long as you follow the correct summer watering schedule to meet the lawn’s needs.
Steps for Watering Wisely
- Check the water flow from your sprinkler. Place a shallow can, like a tuna can, in the center of the lawn and run your sprinkler for 15 minutes. Measure the depth of the water in the can to determine how much water is delivered during that 15 minute period. If it only fills up ½ inch, you must run the sprinklers for 30 minutes to supply a full inch of water.
- Water early in the morning, when possible. Afternoon irrigation evaporates before it soaks into the soil, and evening irrigation can lead to fungus problems in zosyia and fescue.
- Irrigate every two to three days when summer temperatures are below 85 F, or every one to two days when temperatures are higher. Infrequent, thorough waterings encourage deep root growth and grass that’s better able to withstand drought.
- Provide up to 1 inch of water at each irrigation for zoysia grass in the summer, and up to 2 inches for fescue. If you are growing a blend of the two, 1 to 1 ½ inches of water is usually sufficient. Remember zoysia may still brown and die out during the hottest weeks, but it will quickly green up once the temperatures cool.
Maximize Your Irrigation
All the irrigation in the world won’t keep your fescue and zoysia green if you don’t combine it with other good cultural practices.
- Maintain a grass height between 2 1/2 and 4 inches tall throughout summer. Longer grass shades the soil, preventing rapid moisture loss from evaporation. Mowing too closely, or scalping the lawn, is going to cause the zoysia and fescue to burn and dry up.
- Decrease mowing frequency during long, hot periods or in times of severe drought. Mowing too frequently stresses the grass, and increased watering may not repair the damage quickly enough. As a general rule of thumb, cut off no more than 2 inches of the grass blade length while maintaining the 2 ½ to 4 inch grass height.
- Dethatch and aerate both fescue and zoysia lawns regularly. Generally, if the layer of dead grass and debris, or thatch, is deeper than ½ inch, it’s time to dethatch. Annual aerating in spring punches small holes in the soil, which better allows moisture to penetrate to the grass roots.
Automatic sprinklers can simplify your watering schedule, but you can keep a zoysia or fescue lawn green and healthy even if you water manually. Avoiding water stress doesn’t just keep the lawn looking better, it also helps to prevent diseases, pest problems and weeds. A watered lawn is a healthy lawn.