The excessive rains this spring and summer have caused extensive flooding across many areas in Iowa. Turfgrass areas in home lawns, parks, recreational areas, and golf courses have been damaged by flood waters. Turfgrass damage has been due to erosion, deposition of soil and debris, or simply submersion under water.
Rapidly moving flood waters can cause extensive turf and soil erosion. Damaged areas will need to be repaired and seeded or sodded this fall.
Injury may also occur due to deposition of debris and soil. All debris should be immediately removed from turfgrass areas once the flood waters recede. Soil deposits greater than 1/2 inch should also be removed. Also, core aerify the area to promote recovery of the turf.
Turfgrass areas that are flooded for an extended period may be injured by a lack of oxygen. The degree of injury depends upon the turfgrass species, the duration of flooding, the condition of the turf prior to flooding, depth of submergence, and other factors. Kentucky bluegrass, which is the predominant turfgrass in Iowa, is moderately tolerant of submersion under water. A healthy Kentucky bluegrass turf area should be able to survive several days submersed under water. After the flood waters recede, core aerify the area to facilitate the movement of oxygen into the soil.
Turf areas that have been destroyed can be reestablished by seeding or sodding. The best time to seed a lawn in Iowa is mid- August through September. Sodding can be done almost any time of the year when the ground is not frozen or covered with snow.
This article originally appeared in the July 14, 1993 issue, p. 113.