FAYETTEVILLE — The timing of fertilizer applications for lawns depends on whether you're growing cool-season or warm-season grasses.
Warm-season grasses in northwest Arkansas, such as bermudagrass or zoysiagrass, should be fertilized during summer months when they are actively growing.
Additionally, recent re search on bermudagrass found that applications of nitrogen fertilizer during the fall promoted fall greening and did not increase the risk of winter damage to bermudagrass.
However, while you're feeding the bermudagrass, you'll also be feeding winter weeds. I suggest that you consider weighing the cost versus benefit as you develop your fertility schedule.
Is the enhanced color worth the added expense of not only the additional fertilizer, but also the expense of herbicide application to control winter weeds?
That's your call, your pocket book, but if the expense isn't an issue then personal preferences will prevail in your decision.
At the local garden center you will see lawn fertilizer products labeled as "winterizer" that contain a higher ratio of potassium.
It is thought that applying potassium in the fall will reduce winter injury to warm season grasses. However, if your soil already has sufficient levels of potassium, then additional applications is worthless and wasteful. Based on data from the Universityof Arkansas Soil Test Laboratory, approximately 77 percent of lawn soils in Arkansas have sufficient levels of potassium for optimum growth. Therefore, this additional potassium may not be necessary. Before making an unnecessary application conduct a simple soil test through the cooperative extension service will reveal whether or not your soil contains sufficient levels of potassium.
Cool-season grasses, such as fescue, will benefit most from fertilizer applications in the fall (September, October and November) and then again during spring flush of growth (March, April and May). The fall application promotes rootdevelopment which in turn provides better drought tolerance the following summer. The growth of coolseason grasses slows during the hot and droughty period of July and August.
Therefore, avoid nitrogen applications during this time to help reduce disease problems. Again, test your soil to know the fertility requirements before applying fertilizer indiscriminately.
The information in this article was derived from the Turf Tips page of the University of Arkansas Turfgrass Science Website (http:// turf.uark.edu/turfhelp/ turftips.html). To subscribe to the Turf Tips e-mail list visit the Website.
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Mark Bray is a county extension agent with the University of Arkansas' Cooperative Extension Services. Call him at (479) 271-1060 or e-mail [email protected].
Agriculture, Pages 5 on 09/27/2009