Warm weather has prevailed over Wisconsin much of June, and the summer solstice is just days away. Exactly what conditions this summer will bring is difficult to predict, but there are some maintenance strategies to help lawns look their best and tolerate whatever temperatures or rainfall extremes may occur.
Cool-season grasses found in Wisconsin lawns slowdown in growth with typical warmer and drier summer conditions. One lawn care strategy to help lawns hold up to potentially adverse summer conditions is to mow higher. Three inches is the minimum height suggested; consider raising it even higher for the summer months, especially if rainfall is lacking. Lawns mowed taller develop deeper roots and dry out slower if drought conditions develop.
Watering practices are another primary summer lawn care strategy to plan. Decide now to either water your lawn as needed or allow it to go dormant if conditions become dry. Once lawns turn brown and have gone dormant from lack of rain, it is best not to water. Adding significant amounts of water, making lawns green again while still in the heat of summer, stresses grasses. Summer dormancy is an option when caring for most low- to medium-quality lawns. If a prolonged drought were to occur, adding a small amount of water every 2 weeks or so will keep crowns hydrated.
When deciding on irrigating lawns to keep them green all summer, apply water infrequently but thoroughly so it reaches grass root depth in the soil. On average, lawns need about one inch of water per week, from rainfall and/or irrigation. Avoid frequent light watering as it promotes shallow rooting and potential disease and weed issues. Signs lawns need water include wilting, a darker overall color, and foot printing – grasses do not bounce back when walked upon. Ideally water early in the day so grass leaves dry off and less evaporation loss occurs.
For most lawns, fertilizing and weed control via herbicides is not suggested for early to mid- summer. Wait until Labor Day for nitrogen fertilization, as that is the key time for all lawns. Fall is also the ideal time for broadleaf weed control with herbicides, rather than summer. Weeds are much less susceptible to herbicides in hot weather and lawn grasses can also potentially be damaged.
Finally, late summer is the ideal time for lawn renovation work that may be needed. Plan and begin those preparation practices, such as eliminating existing weeds and amending soils, in mid-August. Late August into early September is the optimum window for seeding. Avoid these types of practices in June and July as results are likely to be unsatisfactory.
By Bruce Spangenberg, UW-Madison Division of Extension
