Waterlogged soils create problems When soils are consistently wet, lawns may experience a general decreased growth and vigor over time because of a limitation of water uptake and a stressed out environment, said Leo Schleicher, Extension turf specialist at South Dakota State University.
"Anytime we have persistent surface moisture on the leaves or in the thatch, it provides a perfect environment for disease or pathogen organisms to get started," he said.
Under these types of conditions several different diseases may be at work. It can be difficult to identify which particular pathogen originated it, said Schleicher.
"It may not make too much difference which disease it is because fungicide is not usually applied to home lawns," commented the specialist. Applying fungicide to a home lawn is expensive, plus, by the time symptoms show up, it is too late to do much about it, he said.
According to Schleicher, the best defense against turf diseases is good overall lawn-maintenance practices.
Waterlogged soil is also susceptible to compaction. Traffic on wet soils tends to decrease the pore space, reducing the exchange of oxygen and other gases between the roots and the atmosphere, he said.
"Plants can't take in enough oxygen into their root systems and this impedes some of the water and nutrient uptake," said Schleicher.
Turfgrass can get a condition called "wet wilt." The grass will actually wilt like it would under dry conditions, but it stems from the inability to take up water due to reduced respiration, he said.
A prolonged period of wet, moist, warm conditions can also degrade herbicides faster than normal. Schleicher recommended considering putting on another application of preemergence herbicide in early July if wet conditions continue through the rest of the spring.
To decrease the likelihood of lawn problems, a homeowner should exercise good maintenance practices, said the specialist. People should either bag or rake up lawn clippings if they are excessive. This can result from the inability to mow at regular intervals. "If you leave clippings on the surface of the turf, it only invites more disease problems," he said.
Automatic irrigation systems should be turned off during wet weather conditions. People should also restrict traffic on wet soils to reduce compaction.
Low spots where water often ponds can be filled in with soil and reseeded. The lawn will have better drainage and one won't constantly have standing water where the grass will probably die, he said.
For more information, contact your local Cooperative Extension office.