8/25/2020

The Fall overseeding practice in the Desert Southwest seems to be in a constantly evolving state. The practice of overseeding in years past involved removing as much of the turf canopy as possible to allow the winter cool-season grass to establish, typically within a thirty-day time frame. For the most part, this exercise was performed by mechanical means of mowing and verticutting. This has commonly occurred in the month of October, but, depending upon several factors, can occur as early as late August.  Normally in the Desert Southwest, the underlying turf canopy (bermudagrass) will go dormant for anywhere between six to ten weeks, usually between the months of December through February. During this dormancy period, the bermudagrass will lose its ability to grow and its ability to provide a decent playing surface for the customer.

With the continually changing climatic and environmental issues golf course superintendents face today, there had to be changes made to the practices involved with the overseeding process. As a result, superintendents today have turned to growth regulators, chemicals used to burn back the bermudagrass, and turf pigments as tools to enhance the procedure of overseeding. There are even some facilities that have gone to what is referred to on social media as #liquidoverseed. With this routine, the facility doesn’t overseed the traditional way with a cool-season grass (Rye Grass), but instead uses turf paints, turf pigments, and fertilizer to enhance the overseeding look of the dormant bermudagrass.

One of the overseeding techniques that has evolved is the application of a growth regulator to the warm-season grass to control the vertical growth of the plant and prep it for the overseed process. Syngenta’s growth regulator, PrimoMAXX®, is often used for this. In years past, the typical rate to suppress vertical growth of the bermudagrass during the overseed prep was 16 ounces to the acre. Recently however, there have been courses that utilized between 20 to 40 ounces to the acre. There were even some facilities that trialed 80 ounces to the acre to the see the effects to the bermudagrass.

There are also several selective-type herbicides that are now being utilized during the overseed procedure. When used at low rates, these herbicides subdue and slightly injure the bermudagrass base. This burns back the tips of the bermudagrass, which reduces green waste and in turn requires less mowing and verticutting to scalp the bermudagrass turf base. Ultimately, this leads to a more efficient operation with less manpower required to prepare the turf for overseed. These products include Turflon® specialty herbicide from Corteva, Revolver® herbicide by Bayer, and Scythe® Herbicide provided by Gowan®.

Once the bermudagrass has been prepared for seeding, and the ryegrass has been applied, there are then several days of extensive watering to establish the ryegrass. Once the ryegrass has been established, many superintendents are following up with turf pigments in combination with growth regulators on their tees, fairways, and greens. This combination of a vertical growth regulator at a rate of 6-7 ounces per acre, and a turf pigment at a rate of 16 ounces per acre have become common practice to enhance aesthetics and playability. This application goes down after the first cut of ryegrass and every seven to ten days until dormancy of the bermudagrass occurs.

Harrell’s carries the complete line of products that allows the golf course superintendent the flexibility to tackle any situation that may arise during the overseed process. This includes products from all the major chemical manufacturers and our proprietary line of products, including PAR® SG, and Dormant Green Plus. Reach out to your Harrell’s rep today to get the ball rolling on your overseeding plans.