By By Gary Beaumont
URBANAEven with the extremely wet spring, water is still the best medicine to keep lawns thick and healthy through the summer months.
Most of the lawn problems Im aware of are related to hot, dry conditions. Everything is really spotty, though. While it may rain 10 miles away, we get nothing here, so its difficult to make statements that apply to everybody. In general, we should treat our lawns properly in the spring and fall to help them survive our typically hot, dry summers, said Tom Voigt, U of I Extension turf specialist.
Summer lawn watering can be handled two ways. To keep lawns green, Voigt recommends watering once or twice a week instead of every day and applying a total of 1 to 1.5 inches of water per week under normal summer conditions. To allow grass to go dormant, he recommends cutting back one-quarter to one half inch every two or three weeks. This will keep the grass hydrated enough so that it will not die, but it will go dormant.
Its too early to say this isnt a normal summer. If the drier areas get rainfall in the next week or so, we wont have any unusual problems. Under prolonged drought conditions, we dont recommend watering heavily, then stopping for a month, then starting again. Each time grass is brought out of dormancy, it uses stored nutrients that would be exhausted from doing that.
Homeowners using an ordinary lawn sprinkler instead of an irrigation system can use straight-sided cans to measure how much water their lawn is getting. Several cans should be spread throughout the range being watered because the area closer to the sprinkler often receives more water. Overlapping the sprinkler pattern will make up for the lack of water farther from the sprinkler. Also, during the summer homeowners should not apply any fertilizers or pest-control chemicals, other than grub controls, to dormant lawns. Most fertilizers and weed control chemicals should be applied in the spring and fall when the lawn is actively growing. Be aware that if a lawn reaches dormancy, the potential for heat-tolerant weeds to appear increases.
When the turf is actively growing, homeowners should try to optimize root growth by reducing soil compaction and ensuring there is adequate oxygen in the root zone, Voigt said. For summer-stressed turf, we recommend keeping off the turf and not trying to force a lot of growth with fertilizers. If we have a nice fall with cool temperatures and periodic rainfall, most of our turf will recover very well.