Thatch Reduction

By Ken Quandt, Regional Sales Manager

While thatch accumulation is a potential problem on most types of turf, it is a particular problem on bentgrass and Zoysia. Some thatch is beneficial to the turf, but when it becomes excessively thick, problems arise. It can cause poor playing conditions on athletic turf, limit the rooting depth of the plant, increase the chances for the development of turfgrass diseases, cause mower scalping, and cause localized dry spots to develop.

One of the ways Nature Safe will have an effect on thatch is by reducing how fast it accumulates. Most thatch is caused by excessive shoot growth, and excessive shoot growth is caused by the use of water-soluble, synthetic fertilizers that promote flush growth. The excessive clippings themselves do not add much to the accumulation of thatch, but the old dead stems definitely do. Since Nature Safe does not cause surge growth, the thatch will accumulate at a much slower rate.

Another way that Nature Safe can help reduce thatch is by feeding the soil microorganisms that decompose it. These microorganisms require food to do their jobs, and Nature Safe is loaded with food energy that the soil microbes can use. The rate at which the thatch is decomposed is directly dependent upon the management practices of the turf manager. Even though there is plenty of food available for the microbes, they also require moisture to do their work. Therefore, if your goal is to reduce thatch, you must keep the microorganisms both well fed and moist. Apply Nature Safe every 30 days to maintain a constant supply of food energy and try to keep the thatch layer moist. Keeping the thatch layer moist usually requires irrigating lightly at least three or four times per week. If it is economically feasible, topdressing will help to keep the thatch layer moist by burying it under layers of soil and sand, which helps to hold the moisture in the thatch. If the thatch layer is allowed to dry out, the microbial activity slows down to a crawl. Therefore, the turf manager who irrigates his turf deeply and infrequently will be less successful in the reduction of thatch. While he will see some reduction in thatch, the results would be much more dramatic if the thatch layer would be kept reasonably moist.

If the directions above are followed, it is not unusual to see thatch decomposed at a rate of an inch per year. In some instances, where the conditions are ideal, it is possible to achieve even faster rates of decomposition.