By Geoffrey Rinehart, 'Grass Roots' Program Coordinator for U.S. National Arboretum
Summer can be a challenging time of year for cool-season grasses like tall fescue and bluegrass, especially in hotter areas of the country as temperatures rise. Warm-season grasses are generally more tolerant of hot summer conditions. Without adequate summer rainfall, lawn grass growth may stop completely, and go into dormancy. While many grasses are resilient and can recover from short-term dormancy, a heavily dormant lawn will be much more prone to encroachment from weeds that can do better in these dry conditions.Here are five tips for watering your lawn this summer:
- How do you know when it is time to water? Remember, different lawn grasses will have different tolerance to drought. "Footprinting" and a purple-blue color are often indicators of drought stress. Before the grass turns brown from not enough water, it will fade to a "purple to blue" color. "Footprinting" occurs because the grass leaf doesn't have enough water to "bounce back" after foot traffic and just lays over. If you can look back on an area that you have walked on 30 seconds later and you still see the footprints, this is an early sign of drought stress.
- When you water, water "deeply and infrequently". This mean watering every 3-5 days, but only enough to wet most of the root zone. Be sure to let your lawn dry out between waterings. Keeping the root zone consistently wet by watering frequently can reduce the amount of soil oxygen that is available to the roots and favor fungi that can cause lawn diseases.
- Adjust your automatic irrigation system based on the weather (rainfall, temperature, etc.). Don't just set it at the beginning of the season and forget about it. Better yet, install a rain sensor which can shut the system off when it's raining, so you don't need to worry about it.
- Adjust your irrigation system or sprinkler pressure to water with large droplets. Large droplets are less likely to be blown by the wind and more likely to fall on and penetrate through the soil.
- Make sure sprinklers are correctly aligned at the beginning of the season, and check them often. Sprinklers can get knocked our of alignment by mowers or passersby. You want to make sure you're watering your lawn and not the sidewalk or the house.
Distinctive “footprinting” is an early symptom of drought stress on home lawns