The Right Seed for the Right Need
|By ROBIN WESTMILLER|
Ever wonder why “the other man’s grass is always greener”? Maybe it’s because his landscape contractor planted the right seed for the landscape’s need. Choosing the right grass seed can make the difference between a lawn that thrives and one that needs constant attention—or worse, complete replacement when the plush lawn you thought you had planted turns brown and dies.
When deciding what species of grass to plant, there are three crucial components: location, location, location. For grass seed, this translates into: the temperate zone, the amount of sunlight or shade the grass will receive, and whether the lawn will be subjected to a high amount of traffic. These are important when deciding on the initial selection for new landscape or renovating your client’s existing turf.
Probably the most crucial of these three components is the temperate zone where the seeds will be planted and germinate. The United States Department of Agriculture (USDA) plant hardiness map cites 11 different climate zones in the U.S., based on the average annual minimum temperate for each area.
A multi-climate state, like California, can be in as many as four different zones, but for grass seed, there are basically only three climate zones: cool-season, warm-season and transition. Matching the right climate with the right seed type is tantamount to growing a healthy, plush lawn.
“Grass, like people, thrives best in the climates they enjoy. People who love to ski might not enjoy living in Florida, and people who love the beach and sunshine probably wouldn’t be happy in New York state in the winter,” says Russ Nicholson of Pennington Seed, Madison, Georgia. “Planting a warm season seed in a cool season temperate zone will just kill the grass. The same goes for cool season grasses planted in warm season zones. The summer temps will simply shrivel your grass to nothing.”
The optimum growing temperatures for cool-season seeds range from 60 to 75 degrees. Some typical cool-season grasses include bluegrass, fescues, and ryegrass. Warm-season species thrive in areas of the country where temperatures range between 80 and 95 degrees. Warm-season species are best adapted to the warm arid and warm humid regions. Bermudagrass is the most commonly used species in the warm arid zone, although Zoysia, Carpetgrass, Bahiagrass, and St. Augustine also do very well in warm climates.
The “transition zone” is an area that includes parts of each of the other two climate zones. This is the most difficult region for seeds to grow. The temperatures in the transition zone are cold enough in the winter for cool season seeds, but this makes it difficult to maintain warm-season species. In the summer, temperatures in this zone are warm enough for warm season seeds, but a cool-season species will have a hard time surviving. Because of the variety of climate conditions in the transition zone, you’ll need a highly adaptable seed, or a cultivar—a mixture of different seed species for landscapes that are in a transition zone.
Once you’ve established the climate of the landscape, the next point is to determine how much, or how little, sunlight and shade the lawn will be getting. To choose the appropriate grass seed, you need to evaluate the amount of light falling on different turf areas over an entire day. Light sources can be put into three classifications: full sun, partial shade and full shade.
A full-sun site receives direct sun for at least six hours a day, or more. These are ideal light conditions, and all lawn grasses thrive in these sites. A partial-shade site receives at least four, but fewer than six, hours of sunshine over the entire day.
Some spots may not receive sun, but may enjoy bright indirect light for most of the time. In these areas it is advisable to plant grass seed labeled for shade. Cool season tall fescue, transition zone fine-leaf fescue, warm-season Bahia and St.
Augustine varieties like Better Blue, Delmar, Raleigh, and Seville are recommended for shady areas.
A full-shade site receives sunshine for fewer than four hours a day. In these areas, it will be almost impossible to grow any type of turfgrass.
Instead, you may want to suggest to your client that they plant sturdy, evergreen groundcovers such as pachysandra or ivy.
It is often advantageous to plant a cultivar in a lawn that has variable light, where some areas may be shaded and others may receive full sun. A mixture containing Kentucky bluegrass and red fescue contains species that can adapt and become dominant in these variable environmental conditions. “Red fescue will dominate in shaded areas while Kentucky bluegrass will do well in full sunlight and on imperfectly drained, moist, fertile soils,” says Nicholson.
If your client’s yard is going to get lots of wear and tear—from kids, from pets, from garden parties—planting grass that can stand up to heavy traffic is critical. If a turf’s traffic resistance quotient is low, the lawn will look very worn very quickly. “Buffalo grass can withstand high traffic areas and it also mends itself,” says Steve Black of Bamert Seed Company. “If someone walks over or drives over a wet lawn, Buffalo grass will fill in itself.”
Again, you need to have a good understanding about the particular lawn you’re working with. “You can find a great deal of answers by utilizing the National Turfgrass Evaluation Program (NTEP),” said Murray Wingate, turfgrass sales and marketing manager, Lebanon Turf Products. “Information such as turfgrass quality, color, density, resistance to diseases and insects, tolerance to heat, cold, drought and traffic is collected and summarized by NTEP annually.”
The program establishes tests at university sites across the U.S. and Canada, and publishes unbiased rankings so you can find out which varieties of a particular species ranked the highest in your local area, Wingate added.
Of the cool season grasses, Wingate says that perennial ryegrass handles traffic, mixes well with other grass types and germinates and establishes quickly. It also has good mowing characteristics, while tall fescue requires slightly less water and fertilizer to produce a high quality turf.
In coastal areas, turf can be subjected to salt stress. Burlingham Seeds, Broadview Heights, Ohio, is working on developing salt-tolerant varieties of perennial ryegrass for these parts of the country.
Sometimes a grass seed is more than a grass seed. Sometimes it’s a major player in a sporting event. The soccer training fields hosting the 2010 World Cup in South Africa were in very poor condition before being rescued. Barenburg USA, Tangent, Oregon, flew over their SOS super-fast germinating grass seed in time to save the soccer fields.
“SOS stands for Super Over Seeding, which is exactly what was needed on those training fields,” said Christiaan Arends, Barenburg turf product manager. “The SOS is a combination of perennial and annual ryegrass that germinates very quickly at very low temperatures, which is what was needed in the South African climate,” The purity of the seed is another major consideration. “When the seeds go through the cleaning process, you end up with a varied percentage of inert material and weed-seed content,” says Wingate. “A seed lot might be 98 percent pure, 1.95 percent inert and .05 percent weed seed.” That seed label, if certified, will assure you that the purity of that bag of seed will be 98 percent pure.
No matter what climate, traffic or shady locations where seeds are planted, grass is a living organism that needs sustenance to grow. In addition to sunshine, which is in abundant supply and free, nutrients, which can be purchased in the form of fertilizer, are also required to keep the grass plant healthy. Grass needs an additional component, one that is becoming both short in supply and quite expensive: water.
“What most people aren’t aware of is that there are many different drought-tolerant species of grass that will save water and still thrive. Some Kentucky grasses can go 75 days without a drop of water and remain green, while others turn brown in 30. Bluegrass is the same. There are some that will last 50 days and others that will only last 25 or 30 days,” Nicholson said.
Finding the right grass seed varieties that have a proven drought tolerance and educating the public about these alternatives is no easy task, which is why three seed manufacturers—Pennington Seed, Turf Merchants and Pro Seed—joined resources in 2009 to create the Turf grass Water Conservation Alliance (TWCA).
TWCA recently completed a twoyear study and found that a heat-tolerant bluegrass, which had been promoted as being very drought-tolerant, actually consumed 10,000 gallons more water than a true Kentucky bluegrass did on a 5,000 square-foot turf area. “The heat-tolerant bluegrass simply tolerates the heat by shutting down and turning brown, so people think it needs more
water,” said Nicholson. “It may survive the heat, but it’s not drought-tolerant, so to keep the turf green for at least 50 percent, it needed to consume 10,000 gallons more water than a true Kentucky bluegrass would. So they really did plant the wrong grass in the wrong place, and the water consumption went through the roof.”
Landscape seeding and proper irrigation has to be a coordinated effort; a unified partnership across the board. Putting the right seed in the right place is fine, but if the seed is not watered in a timely manner, little if any germination will occur.
Creating the perfect lawn and conserving water in the process is a partnership between the landscape contractor and the property owner. It may take a bit more time to educate your clients, but the rewards will be well worth it . . . especially when they’re running barefoot through their freshly mowed lawn.