Editor’s note: Christopher S. Gray Sr., a professional product manager from LebanonTurf, has been addressing fertilizer issues in this special column the last several months. This month, Gray addresses the advantages of fall fertilization.
With the fall season already coloring our landscape with various shades of orange, yellow and red leaves, it’s time to turn our attention to the most important fertilizer application of the year — the fall application. It’s by far the biggest bang for the buck in terms of the numerous benefits it provides to the overall management plan for your turf, especially the following season.
Fall fertilization has been a staple of professional turfgrass management for a long time, and there’s no reason to believe that it’ll be changing anytime soon. With the recent winters becoming harsher and colder, reviewing the benefits of this practice seems like a good idea.
The term “fall fertilization” should not be confused with what many professionals call a “dormant feed” or “winter fertilization.”
These two terms refer to nutrient applications made after the turf has turned mostly brown and is becoming dormant. Fall fertilization refers to applications done while the turf is still green and actively growing.
With the much cooler fall temperatures, it’s critical to choose a proper nitrogen source for the application. Nitrogen sources that rely solely on microbial activity to release should be avoided.
The key is to utilize quickly available nitrogen sources like ammonium sulfate, straight urea, highly active methylene urea, or an ammonium sulfate/methylene urea complex. Utilizing one of these sources will ensure that the turf stays green late into the fall and early winter.
This fertilizer application will directly influence the stimulation of plant root growth during the fall. Timing is key. The application should be made so that the temperature drops to the point where root growth is favored over shoot growth.
This is the perfect model for the fall fertilization, since root growth ideally occurs when soil temperatures range from 45 to 65 degrees Fahrenheit, while shoot growth is favored between 60 and 75 degrees Fahrenheit. Depending on the turf species, some root growth will continue to occur until the soil actually freezes.
The true advantage of this root growth is realized the following spring. Fall-fertilized turf greens up an average of two to six weeks earlier in the spring than turf not fertilized in the fall. This is achieved without an early-spring nitrogen application, which usually causes excessive shoot growth, or flush growth, pushing forward the start of mowing season and possibly promoting some patch diseases. Multiple university research studies have illustrated that the spring color of fall-fertilized turf will remain very good until late spring or early summer.
The Farmers’ Almanac is calling for another ruthlessly cold winter in 2015. So go ahead and prepare your golf course for winter and spring by making the most important fertilizer application in your nutrient management plan.