Why pay attention to all the writing on grass seed bags? Grass is grass, right? Wrong.
Just as different varieties of corn and tomatoes perform differently and have different characteristics, so it is with grass seed. All grass seed is not created equal. Not only are there many different species or kinds of turfgrass available for use in home lawns, each species has literally hundreds and hundreds of different individual varieties. Each variety has been bred or selected for different characteristics – primarily in the never-ending search to find the toughest, greenest, most bug- and disease-resistant types for golf courses and athletic fields.
Scientists and researchers field-test thousands of grass seed varieties every year at universities and trial plots all across the United States and Canada. The results are published online so that seed companies can keep up to date on the latest, greatest introductions and home gardeners can tap into the same useful information that the pros use. These results are published free to the public by the National Turfgrass Evaluation Program at www.ntep.org. Once at that site, you can research types by your own state or by the species of grass seed.
What the NTEP tests reveal
Visit any of these NTEP test sites, and it’s fascinating to see the obvious differences in performance in the various blocks. Most plots are laid out in 4-by-6-foot rectangles that are each planted with a different variety of grass seed. Often times the differences are so striking that even a 4-year-old could pick out the superior types, even though all the grasses are grown in the same soil in the same field. If you think grass is grass, a visit to any of these sites will quickly change your mind.
Researchers look at all kinds of performance factors – things like color (both in summer and winter); blade texture; turf density; resistance to common lawn diseases such as red thread, rust and brown patch; resistance to bugs, and tolerance to traffic and drought. Varieties are scored in these areas, and those are the numbers posted on the NTEP site along with overall best varieties for each species.
This kind of data makes it possible for home gardeners to stack the odds in their lawn’s favor by learning the best varieties and seeking them out instead of buying any old grass seed and hoping for the best. Although grass seed is one of the least expensive components of planting and maintaining a home lawn, experts will tell you that grass seed varieties make a huge difference in ultimate performance. Many of the newest varieties are especially adept at fighting off bugs and diseases that otherwise would decimate a lawn with older, less-resistant grass types. Other new grasses are being chosen for their richer and longer-lasting color and for their ability to bounce back from droughts.
Picking the right grass seed
With so many choices, how can a homeowner zero in on the best one for his or her lawn? The first decision is to figure out which main species – or blend of species – makes the most sense. In the South, so-called "warm-season grasses" such as St. Augustine grass, bermudagrass and zoysia grass are commonly used because they hold up best in hot, humid summer and warm winters. In the North, most lawns are composed of one or more of four "cool-season" types: perennial ryegrass, Kentucky bluegrass, fine fescue and tall fescue.
Each grass type has its strengths and weaknesses, and so a home gardener can exploit that by matching the type to what’s most important. For instance, perennial ryegrass fills in nicely and germinates quickly, making it great for patching and overseeding. Kentucky bluegrass has excellent color and performs well in full sun. Fine fescues have narrow textures and are more tolerant of shadier spots than ryegrass and bluegrass. And tall fescue has a coarser look but is toughest in high-traffic sites and in hot spots that are prone to drought. Many seed companies blend two or three types together in one mix to take advantage of at least some of the best of all worlds. The percentages of each type can even be varied to target differing goals.
Need help selecting your cool season or warm season grass? Check out the performance characteristics for "Cool Season" and "Warm Season" grasses.
Once the overall aim is decided, what makes the final difference is going with specific varieties that have tested highly — especially in a climate and soils close to your own. That’s another of the benefits of the NTEP data – you can search for localized results from the closest test site.
To further improve their grass seeds’ performance, seed companies often mix together more than one variety of each species. The result is that a bag of grass seed might contain three different species and six or eight different varieties. This is all listed on the label on the back of grass seed bags along with the percentages of each, the germination rates and the estimated percentage of weed seed in the mix. Reference "How to read a grass seed label" article.
Planting the grass seed
Once you’ve got quality grass seed, it’ll germinate best in cool weather (i.e. spring and fall) when the seed is in good contact with the soil. Whether seeding or overseeding, it’s best to scatter grass seed over loosened soil and then lightly rake it in so the seed is distributed throughout the top quarter inch. It’s fine for some of it to be at the soil surface. Rolling or tamping the seed into the ground helps ensure that the seed is in good contact with the soil. Watering also will help drive seed into roughed-up soil.
Another option is renting a "slit seeder," which is a gas-powered machine that cuts vertical slits in the lawn and deposits seed into each slit through a hopper – all in one pass. Some people also overseed after they’ve roughed up the soil by core-aerating (removing soil cores with a drum-type machine) or by dethatching (hand-raking or using a machine that tears thatch up and out of the turf’s surface).
Keep the new seed consistently moist until it sprouts. Sprinkle lightly but often until it’s up – ideally two to three times a day for about 10 minutes each. Once the seed is up, irrigate every few days for the next several weeks so those baby roots don't dry out. A starter fertilizer also is helpful at planting time for getting the young grass off to a good start. A light mulch can also help retain soil moisture. Straw is the old favorite, but carries weed seeds that will germinate along with the grass seed and compete for space in your lawn. I suggest trying one of the newer approaches that use recycled newspaper and polymers that are designed to readily absorb and hold moisture to aid germination.
Planting Grass Seed, try these lawn products from GreenView: