When the long hot summer finally fades into crisp fall, homeowners' thoughts turn to breathing new life into their lawns. While most homeowners use the old standby fescue lawn seed, there are a lot of grass seeds to pick from and a lot to consider about maintaining a good-looking, healthy lawn.
N.C. State University's crop science department runs trials on 700 varieties of grasses.``In general, we look at the color, density, quality, incidence of weeds, winter and summer survival of each variety. Adaptability trials depend on a grass's purpose and intended use,' said Dr. Art Bruneau, extension turfgrass specialist.
Certain varieties will look good at certain times of the year, but ``there's no one grass that will do all things for all people,' Bruneau said.
Factors to consider when choosing a grass variety include the amount of sun your lawn gets, whether it has a northern or southern slope and the type of diseases prevalent in your area, he said.
When to grow a lawn depends on the type of grass used. Cool season grasses stay green in the spring and fall and slow down in growth in the summer. Tall fescue and Kentucky blue grass are two popular ones used in this area.
Warm season grasses such as bermuda, centipede and zoysia do well in the middle of summer, turn brown or dormant at the first sign of frost and take their time greening up in the spring, Bruneau said.
For this area, Bruneau recommends a blend of tall fescue and Kentucky blue grass seeded in the fall.
Those who prefer using sod can find these varieties there too. ``One of the advantages of sodding is you can establish a lawn at other times of the year when you'd never want to go in and seed it,' Bruneau said.
Sod may be the answer on slopes that need erosion control because it gives you an instant lawn.
Whether to seed or sod depends on several factors, said Gene Cross, weed specialist with the N.C. Department of Agriculture.
``A lot of it depends on cost. Some homeowners are willing to pay for an instant turfscape. Sodding would require some renovation to get the lawn ready and quite a bit of follow up in terms of watering to keep it alive until rooting takes place.'
``Grass seed is several times cheaper than using sod,' said Marihelen Glass, director of the horticulture program in the plant science and technology department at N.C. A&T State University.
If you decide to use sod, Bruneau offers this caution: ``It's important that the homeowners realize they can't cut any corners. The area has to be tilled, soil tests taken, nutrients and lime incorporated to a depth of 6 inches. Final grading should be put in place, then it should be sodded. One of the keys to a sodded lawn is to make sure you have everything ready to go.'
Sod should be taken off its pallets and laid on the ground within 24 hours after it is delivered. ``If it's left on pallets it's like a compost pile,' Bruneau said.
One strip should be butted up against another in a brick-like pattern. Stagger it so that seams are not together. That leaves no spaces for crabgrass and no air pockets. On a slope, lay the sod sideways so that seams do not run up and down the hill. That prevents erosion problems.
Once sod is laid, water it down to an inch or two beneath the sod. You can tell if it's knitting by lifting a corner. You should see root growth after a week or so.
Seeding is ideal in September for cool season grasses. In the Piedmont, ``fescues generally do real well,' Cross said. Some varieties are more drought tolerant than others. Check with your local agriculture agent or lawn and garden supply center.
All grass seeds sold in North Carolina must have a minimum germination rate of 70 percent, Cross said. The seed label should indicate the purity and germination levels. There is no minimum percentage of purity required, but seven types of weed seeds are prohibited and 15-20 types are restricted.
Once seed is purchased it should be sown because it will deteriorate over time. ``If you're going to purchase it in the fall, you should get it out then for maximum germination. You can keep it from season to season, but it's not going to do as well,' Cross said.
Because clay soil in this area is ``like growing in concrete,' adding material is advised.
Glass recommends using any type of compost that's been decomposed, including grass clippings, peat moss, manure, vegetable waste and shredded newspapers. She advises spreading the rich mixture over the top of the soil and tilling it in 6 to 8 inches deep.
Once you've seeded your lawn, depending on weather conditions, you need to water it extensively through the first week or two, until you begin to see grass established.
After that, water two or three times a week, depending on how dry or wet it is. Then water according to whether the lawn is in full sun or not. Cross advises limited watering for the first three months into the winter. ``What you're looking for is good root establishment,' he said.
With a statewide ban on lawn clippings at landfills expected in 1993, now's a good time to put clippings to use.
``The bottom line is in most instances homeowners can recycle the clippings or nutrients. The idea is you can allow those clippings to fall through the canopy and they'll release nutrients that'll help the plants,' Bruneau said.
If you leave grass clippings on your lawn, you may not need fertilizer, Glass said. If you mow your lawn regularly and leave the grass clippings on it, ``it's going to be green enough' if it gets enough water.
But if you want more encouragement, you can fertilize in the spring when the lawn starts to grow and again in August.
Cool season fescue grows mostly in the fall and early spring, so ``it's better to give them two shots of fertilizer,' Glass said.
Don't use herbicides until the lawn is well established. Then use fertilizer and weed control early in the spring and again in the fall.
Weeds shouldn't be a problem after your lawn's established, but if you want to be sure, Glass recommends using a pre-emergent herbicide. Work it into the soil at the same time you work in the compost material.
That way, the herbicide will kill the weeds before they come up. For stubborn broadleafed weeds such as dandelions or clover that show their faces later, Glass advised using a post-emergent herbicide.
For established lawns, Cross recommends at least an annual fertilization and a winter weed control program. He said a fertilizer mixture of 8-8-8 or 10-10-10 works well in the Piedmont.
An improved variety over traditional Kentucky 31 fescues is the tall fescue, a turf-type grass. Advantages include its finer texture and a lower mowing height than Kentucky 31, ``even though we still prefer to mow it 3 inches high,' Bruneau said.
The variety is leafier, although it's no more heat and drought resistent than the traditional Kentucky 31. It also does well in partial shade, although it won't grow in very densely shaded areas, Bruneau said.