Turfgrass Varieties for Mid-Atlantic Lawns
Choosing a lawn grass in the mid-Atlantic is very difficult since much of the regions falls into what is known in the world of turfgrass management as the ‘transition zone’. Or, as a friend that always struggles with their lawn says “Forget ‘transition’—it’s the “Twilight Zone”… nothing ever makes much sense when it comes to my lawn”. It’s tough for sure, but there are some logical steps to improve your chances of having a decent lawn with minimal inputs.
After determining which turfgrass species (fescue? bluegrass? bermudagrass? zoysiagrass? etc.) is the overall best possible selection for your climate, your specific site characteristics, and your particular needs/desire for a lawn and its use, the next step is to select the best adapted varieties (i.e. cultivars) within that species. The Turfgrass Teams of Virginia Tech and the University of Maryland partner in the development of an annually updated turfgrass variety recommendation list based on field performance trials located in Blacksburg, College Park, and Virginia Beach. These trials, conducted through the USDA-sponsored National Turfgrass Evaluation Program (NTEP), last for six years and consist of replicated blocks of the latest releases in turfgrass varieties along with industry standards. Regular visual ratings are made on variables such as turfgrass quality, color, density, and tolerance to pest pressure and since the mid-Atlantic offers such a diverse climate, the data are pooled across the three test location sites to identify cultivars that have provided top performance over time regardless of location. Any time you want to get really specific about turfgrass performance in your region, you can access all the data reported from across the country at the NTEP website, www.ntep.org.
The Virginia/Maryland list contains two categories of merit for most species: Recommended and Promising. For any variety to achieve one of these designations, it must be a named cultivar, it must be available as certified seed and/or sprigs or sod, it must be tested in both Virginia and Maryland, and it must perform in the top statistical categories for a minimum of two years to be designated as ‘promising’, and at least three years to be designated ‘recommended’. For bermudagrasses, the list goes one step further in detailing varieties that can be classified based on their genetic cold tolerance, and therefore give a recommendation to where certain varieties can and can’t be used on the basis of winterkill potential.
Appearing on the list does not guarantee success; it simply means that the variety has delivered consistent, top quality field performance in the climate, maintenance programs, and soil conditions at our site. The list also does not guarantee availability of these sources in your area, a common frustration for many homeowners seeking to purchase recommended varieties from local big-box retailers. Specialty turf and garden stores are almost always more likely to have (or be able to get) cultivars from the list. The personnel at the specialty stores are very likely familiar with the variety recommendation list and can even offer valuable suggestions on cultivars and combinations that best meet your specific situation (sun/shade, high or low maintenance, traffic/no traffic, etc.) and desires for a lawn. Big-box retailers will likely have a limited selection of cultivars that may or may not be on the list. This certainly does not mean a seed source from the big-box retailers is not suitable; quite often they carry well-known varieties with proven track records of performance.
One thing that almost always pays dividends in the long-term performance of cool-season grasses established from seed is to take advantage of the benefits of genetic diversity. What this means is, select and/or develop blends (combinations of two or more of the same species) or mixtures (combinations of two or more cultivars from different species) whenever possible for cool-season lawn establishments from seed. The diversity from slightly different genetic material enhances the ability of your turf to survive pest and/or environmental pressure. The reason why is that one variety will probably respond differently to the stress, thus improving the chances that something in the lawn survives.. It has long been common to purchase ‘sun/shade’ seed mixes that contain Kentucky bluegrass, perennial ryegrass, and fine-leaf fescues. This mix takes advantage of the long-term strengths of the grasses where bluegrass will ultimately dominate in the sunny areas, the ryegrass provides quick coverage, and the fine-leaf fescues ultimately dominate the shadier spots. And while it used to be discouraged due to the difference in leaf texture and growth habit, it is now even quite common to purchase mixtures of Kentucky bluegrass and turf-type tall fescue due to their similarities in appearance from the new generation of grasses.
In summary, there are plenty of challenges in choosing a ‘best’ lawn grass in the mid-Atlantic due to our highly variable climate and soils. However, once you’ve decided on a species that best fits your situation, choosing the best adapted varieties available is an important first step towards having a great looking, environmentally friendly lawn.