One of the biggest pros is enjoying a beautiful, lush, green lawn during the height of the summer heat. The biggest con is getting the water bill later. The best time to decide if you are going to water is really spring. This puts into play additional lawn management practices. If you are going to water all summer that changes the fertilizer program, how often you will need to be mow the lawn, how high to mow, and how to handle the lawn clippings. Depending on the age of the lawn, disease management also may be on your list.
Choice 1: Water the lawn
If you’re watering, then the lawn will take a higher level of care, including the need for more fertilizer. Our typical cool season grasses would naturally expect to go dormant during the hot, dry summer, so when kept alive, it means the need for more energy. With more inputs like water and fertilizer, the time spent on the lawn increases. More water and fertilizer also will drive the mowing question – how often and how the high. One of the best ways to keep the lawn looking good is to mow higher, more often, and with a sharp mower blade. (Pro tip: on most lawn mowers choose the second highest setting on the deck. This actually works very well for the lawn whether you water or not.)
With higher amounts of water and fertilizer, the potential for lawn fungal diseases can increase, especially with older lawns more prone to disease. A good preventative practice is to water so the lawn dries well before the end of the sunshine. Consider starting on the north or east sides of the home where it will take longer to dry and finish, than on the southern and or western exposures.
Choice 2: Rain only
If you are not going water and let Mother Nature do her thing, the lawn will remain green as long as the rain lasts then naturally go dormant. With this choice, besides saving on the water bill, additional cost savings will be found in less fertilizer, as you will not be using any during the time the lawn is dormant. Plus, less mowing means less fuel for the mower and the frequency of how often you mow will lessen. The mowing height should be maintained though. The taller grass blades further shade the soil, helping to retain what soil moisture is there.
With either choice, a good cultural tip is to consider topdressing the lawn with quality black dirt or organic matter annually. Organic matter will absorb and hold water for the lawn to use later as well as feed the lawn the micro-nutrients not found in synthetic fertilizers.
About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.