Dakota Gardener: Spring lawn problems
The winter of 2022-23 just keeps on giving! With the snow mostly melted, our Dakota Gardener readers may notice their lawns are a mess but for vastly different reasons. Across the region, we have three different situations that have resulted in lawn damage: persistent snow cover, the 2022 drought and spring flooding.
Gray Snow Mold
For those that endured deep snowdrifts for what seemed like an eternity, you may see matted down, straw-colored patches of grass. A cotton-like webbing may have briefly appeared. No, this isn’t a giant spider horror movie. Rather, this is indicative of a fungal disease called gray snow mold and it is most prevalent where the snow was piled.
The incidence of snow mold increases when snow cover exceeds 90 days. With our long winter, we definitely met that threshold.
While snow mold damage may look alarming, it is usually a short-lived problem. After the lawn is no longer muddy, rake up the matted areas. If lawn patches have died, reseed the bare spots. Fungicide applications in spring are not effective.
Lessening the severity of snow mold damage depends upon your fall lawn activities. Late fall applications of fertilizer are not recommended because nitrogen makes the turfgrass more susceptible to this disease. Regionally, the final fall application of fertilizer should occur no later than September. Furthermore, continue to mow the lawn until the grass stops growing in the fall to prevent the turfgrass from matting.
Fall fungicide applications are not recommended for homeowners. Fungicides for snow mold are very expensive and may not be effective. The application timing is very tricky because it must be done right before a snowfall.
With our snowy winter, we forgot that large areas of the region experienced drought or abnormally dry conditions last summer and fall. Fall is an important time for the lawn to recuperate after summer stresses and drought. If you irrigated your lawn after the summer and it greened up last September, the turfgrass will be in relatively good shape this spring.
Conversely, if the lawn went dormant last summer and did not receive much moisture in the fall, significant damage may have occurred. In that event, readers may need to overseed thin lawns. If large areas died, a lawn renovation may be necessary. In the future, make sure to bring the lawn out of dormancy by irrigating during the fall.
From fall drought, we now transition to spring flooding along rivers and streams. Fortunately, lawns can survive a few days of being submerged by spring floods due to the cold water temperatures. Summer flooding with warm water temperatures is much more lethal.
If flooding occurs, rake or shovel off the flood debris and silt as much as possible to prevent the lawn from being smothered. Once the area is dry, consider core aeration to relieve compaction and to allow oxygen to reach the turfgrass root system. Overseeding the lawn is also recommended.
Phew! We’ve talked about fall drought, heavy snowfall and spring flooding in the same article. Here’s to hoping the weather is more moderate this spring!