Summer lawns need proper care to grow deep roots
Q. What are some tips for taking care of my lawn this summer?
A. Resist the temptation to fertilize your lawn. Fertilizer is not necessarily the best thing. Adding nitrogen fertilizer tends to stimulate shoot development at the expense of root growth. Cool spring temperatures favor root growth more than shoot growth, which creates a denser and deeper root system for the turf. That deeper and denser root system means a better chance of survival for the dry summer. Emphasis on "dry." Therefore, our lawn-care goal should be more on developing a deeper and more extensive root system rather than encouraging green thick shoot growth, which will happen as temperatures increase.
As soon as the grass needs cutting, mow it. Don't wait! If you let the grass get tall before mowing, you run the risks of stressing the plants and encouraging diseases. Turf should be mowed as needed.
Occasionally weather or schedules prevent mowing turf when it should be done. A basic recommendation is to remove no more than one-third of the grass blade at any one mowing. The one-third rule helps maintain maximum turf root growth.
Research indicates the taller the grass blade, the deeper the roots. Deeper roots allow the lawn to resist drought damage and stay green longer. The taller blade will shade the soil, which will keep it cooler and retain soil moisture.
Also avoid mowing wet grass as it encourages the spread of diseases and can lead to an uneven cut. If the grass is too tall, consider bagging or use a mulching mower to limit thatch buildup.
Frequent and close mowing in the same direction or pattern can cause the turf shoots to lean in the direction of the cut. By altering the mowing pattern with each mowing, the turf shoots tend to grow more upright, reducing strain.
Three other basic mowing recommendations are to maintain mower blade sharpness, sharpen once a season, mow when the turf is dry, and avoid making sharp turns when mowing.
In Illinois, there are two ways to manage summer irrigation of your lawn. One is to water your lawn as needed. Water early in the day, preferably before 10 a.m. In addition, watering early can reduce water loss due to evaporation and also reduce the incidence of several lawn diseases. Cool-season lawn grasses, bluegrasses, ryegrasses, fescues and bentgrasses, require about 1 to 1.25 inches of water per week during the growing season to maintain green and active growth, depending on temperatures. That being said, the growth of cool-season grass slows during summer's hot, dry weather due to conditions that aren't within the optimum range for growth.
An alternate method of managing lawn irrigation is to allow the lawn to go dormant during hot, dry weather. Unwatered lawns of cool-season species normally become dormant and brown during these hot, dry periods and recover acceptably when growing conditions improve in late summer or early fall. During prolonged drought periods, apply .25 to .50 inch of water every two to four weeks to unwatered lawns. This will maintain moisture in stems and roots.
- Terri Passolt
• Provided by Master Gardeners through the Master Gardener Answer Desk, Friendship Park Conservatory, Des Plaines, and University of Illinois Extension, North Cook Branch Office, Arlington Heights. Call (847) 298-3502 on Wednesdays or email northcookmg@gmail.com. Visit web.extension.illinois.edu/mg.