By Bryan Ostlund & Grady Miller, PhD
Everyone, from fan to player to coach, can appreciate a vibrant green playing field. There is no doubt about the visual benefit that overseeding a playing field can bring. However, as a sports turf manager, appearance isn’t the only factor to consider when weighing the options for a green field year-round. Overseeding can generate additional benefits associated with turf health, field playability and turf protection, all of which can play into the turf management and maintenance decision.
Overseeding allows warm-season turf to appear green year-round. While warm-weather turf will go dormant when temperatures drop, a cool-season grass–such as ryegrass—will flourish. If you’re not already overseeding your warm-season playing field, consider these three distinct benefits that go beyond appearance when making the call this fall:
By maintaining turf that actively grows throughout the cool season, like ryegrass, turf managers introduce a grass that acts as a protective barrier. Active growth holds up better than dormant grass, minimizing wear and tear that can lead to brown or bare patches.
The rise in paint applications has created new opportunities to achieve a green playing field despite dormant turfgrass, but offers only marginal improvement in wear tolerance (via encouraging growth later in the fall and earlier in the spring). Too much traffic without any overseeding protection that allows turf to grow actively and recuperate can result in field failure. By overseeding with perennial ryegrass, turf managers can achieve a lush green look year-round, while guarding against high-traffic wear and tear that could otherwise result in significant repairs or even the need for replacement come spring.
Actively growing grass provides a more dynamic, softer playing surface that’s better and safer for sports than a dry, dormant field. For regions that see heat fluctuations even in the winter, a field with actively growing turf offers a natural cooling effect, making it more comfortable for players. Additionally, routine overseeding can result in a more dense, uniform and safe playing surface that provides increased stability for players. In some cases, an overseeded field may be more consistent for ball roll than a field with warm-season grass, such as bermudagrass, during dormancy.
Overseeding with ryegrass in the fall may aid in kick starting your bermudagrass in the spring. In the same way that heavy traffic can impact a dormant playing field in the fall, excessive wear can also slow the regrowth of dormant bermudagrass in the spring. Worn dormant grass introduces bare ground that is more subject to wear and erosion and increases the incidence of weeds.
If overseeding is an option that sounds right for your field and conditions, start planning now for the best approach in your region. Several factors will need to be taken into consideration, including the timing of seeding, coverage, variety and methods.
First, timing for overseeding is relative to conditions and region. Contact your local agriculture university extension office for specific seeding advice in your region. In the Deep South, general guidelines lean toward overseeding for football in early October and baseball in the late winter or early spring. However, in a transition zone area overseeding for baseball must also take place in the fall, as it is too cool for establishment in late winter to early spring, which would likely result in a stand failure.
During the fall, it is common for cool-season grass to come in at a more controlled rate, which allows it to be more tolerant of wear and disease. If you are expecting a lot of wear and tear, be generous with your seed distribution. And although overseeding may be influenced by the sport, it’s best to use climatic conditions as the determinant of when to seed.
Next, determining whether to apply all cool-season seed at once or to do so gradually is a personal choice. If you decide to overseed all at once, make sure it is the ideal temperature and you will have the best opportunity for a lush, even turf. Some field managers prefer to trickle in seed. This is more of a conservative approach that may result in germination issues and often doesn’t allow much time for correction before the germination period ends. A nice alternative is to seed 75% at once, and then hold back the rest to trickle in as needed to fill bare or worn areas.
In terms of selecting a variety, perennial ryegrass seed works best for overseeding warm-season playing surfaces. Talk with your local extension office to identify a seed that has tested well in your area and be open to change.
Seed has come a long way. If one doesn’t work well, don’t be afraid to change it up and try a new variety recommended by local experts.
Finally, there are some tips to successfully overseeding. For instance, make sure seed is distributed as evenly as possible, and don’t try to do it by hand. Use equipment that distributes evenly and in opposite directions. Additionally, when using last year’s seed, make sure your seed has been stored in a cold storage or air-conditioned space. If you must use old seed, mix it with new seed to increase the likelihood for success. Seed you have been holding on to for multiple years may not germinate.
Everyone loves a lush, green playing field, but overseeding is a smart choice that extends beyond looks. Perennial grasses can improve the overall health and durability of your field, while providing athletes with a more stable surface for play. Consider these critical benefits as playing seasons are upon us and fans, coaches and players alike look to you for a safe and attractive playing field.
Bryan Ostlund is Administrator, Grass Seed USA, and Dr. Grady Miller is Professor of Crop Science at North Carolina State University. Grass Seed USA is a national coalition of grass seed farmers and academic turf specialists with a wealth of experience in studying, growing and harvesting grass and grass seed. The coalition seeks to inform and educate residential and commercial customers about the benefits of grass and best practices for responsibly growing and maintaining healthy turf. For more information, visit www.weseedamerica.com or follow @WeSeedAmerica on Facebook and Twitter.