Establishing Turf from Seed

Mid-August through September is the best time to establish turf grass areas from seed. Sowing grass seed in late summer has several advantages over spring seeding. Grass seed germinates quickly in the warm soils of late summer. Once the grass seed germinates, the warm days and cool nights of fall promote rapid turf growth. Also, there will be less competition from weeds as fewer weed seeds germinate in late summer and fall.
Spring plantings work well too, but, in the northeast, it's best to get them in before the end of June. I've installed lawns at the height of summer with good results, but, unless you have time for lots of watering and mothering, it's best to wait for late summer and spring.
The first step in planting a new lawn is the establishment of the rough grade. Remove any construction debris or other rubble, then fill in low spots and level off high areas. The rough grade should slope away from the house foundation, driveway, and sidewalks. The rough grading should be done well in advance of seeding to allow for settling of the soil.
After a few days or a light rain, you can see areas where the ground has settled and needs filling. Don't dustup the area if heavy rain is expected or steep slopes will cause erosion.

At least 4 to 6 inches of good soil are needed to establish a lawn. If necessary, bring in additional topsoil or organic matter. Incorporate the additions into the top 6 inches of soil using a rototiller. If the soil is reaslly stoney, you can till just the first inch or two, unless you love to rake rocks and pick them up with the wheel barrel or loader!
You can establish a lawn with less soil than this but, it will take patience and constant attention over the next couple of years to get the lawn to take in such a way that you won't have to be always playing with it to assure it's long term viability.

The best way to determine fertilizer needs is to conduct a soil test. Most of the soil test kits you can buy at the hardware store aren't very good. Your local university extension service often can provide you with a one time soil test or, some, more progressive landscape outlets sell them. Apply the recommended type and amount of fertilizer, and incorporate the material into the soil to a depth of 6 inches using a roto tiller or rotavator. Applying it to the service is what most people do, and, that's perfectly okay, especially with organic fertilizer. If you happen to have access to a large tiller you can use that to stir it into the soil. However, if you live in an area where the sub soil is stony I would just apply it to the service, otherwise, you'll wind up bringing up all the stones again and have to rake the whole place, one more time.
You can buy a useful pH kit at your local hardware store or landscape center.
Lawns thrive in a pH of 6.2 - 7. Some where in the middle, about 6.6 is preferred.

The final step in soil preparation is hand raking the area, even if you've already used a landscape rake, or, what some would call a York Rake, because, there are always left over rocks, clumps and debris and soft spots that need hand work.
Every installation is different and requires different amounts of different types of treatments.

Select the appropriate grass species for the site. In sunny areas, Kentucky Bluegrass blends are the best adapted turf grass. The fine textured fesuces (creeping red fescue, hard fescue, and chewing fescue) tolerate considerable shade and are the best choice for shady sites. Sow the seed with a rotary or drop-type seeder. Sow half the seed in one direction; the remaining half should be applied at a right angle to the first application. After the seed has been sown, walk over the area to inspect the relative seed dispersal, and rake out any areas that may have excessive seed and drag it to areas with any bare spots or sparse application close by. If you've used a York Rake, you'll notice the seed is finding it's way into the small valleys created by the rake. This is a good thing. It protects the seed from blowing around, ensures better seed dispersal rates, allows the moisture to remain in the crack with the seed and ensures better germination. Next, roll the site to insure good contact between the seed and the soil. A professional landscaper might use a drill seeder to apply the seed or, hydroseed.
I personally never used Hydro seeding as, the fertilizer incorporated into the mix isn't organic, and pollutes the water table and, the mulch material is ground up news paper that might have contaminates in it. It is a very popular practice however.

To conserve soil moisture, mulch the area with clean, weed-free straw. One bale of straw should cover approximately 1,000 square feet. Using a bale chopper is the best way to do this on large areas. You can use hay, but, hay will contain many species of undesireable grass and plants, if it's fresh hay. Even old hay can still contain viable seed from other plants. It will do in a pinch, or on areas where you don't care too much about appearance, but, staw, or landscape netting is preferred.

After the ground has been mulched, water the area. Keep the upper 1-inch of soil moist with frequent, light applications of water. Newly seeded areas may need to be watered once or twice a day if it doesn't rain that often. Most turfgrasses should germinate in 2 to 3 weeks if the seedbed is kept uniformly moist, unless your seed mix contains some annual grass. then you may see some green grass in a week or less. Gradually reduce the frequency of watering, but water more deeply, when the turfgrass seedlings reach a height of 1 to 2 inches.

The new grass should be mowed when it reaches the height of 3 1/2 to 4 inches. Make sure the mower blade is sharp. Mow at a height of 2 1/2 to 3 inches. Regular mowing through the fall will help thicken the turf. A lawn seeded in late summer should be well established by November.

LAWNS: PREPARATION FOR PLANTING TURF
 
MG Manual Reference
Ch. 12, pp. 14 - 18
University of Arizona

Selection of the proper turfgrass variety for a lawn, based on the site and intended use is the major factor in the successful performance of a lawn. If you have selected a turfgrass which will be established from the seed, the next question is to acquire the seed for planting. In order to better understand what's in the "seed bag," you should be able to read the "seed tag." The seed tag is a legal document which contains important information about the integrity and condition of the variety(s) and other materials sold to you as the final product. For seed that travels from state to state, Federal Seed Act (FSA) requirements must be met which require the following information:

1. Seed Lot Number: used for permanent identification.
2. Kind of Seed: accepted or common crop name. Examples are perennial ryegrass, tall fescue, common bermudagrass.
3. Percent Pure Seed: this is the amount of seed by weight for each variety. This includes the name(s) of the variety or varieties included. If no variety is claimed, then VNS (variety not stated) appears on the tag.
4. Other Crop Seed: this includes other unnamed varieties of the desirable turfgrass species, or other species of other grasses or crop seeds. This can be up to 5% by weight of the seed bag.
5. Weed Seed: this is the percent by weight of the seed bag which contains either noxious weeds, and/or other weed seeds. If noxious weeds are present, then usually strict limits are imposed as tolerance limits.
6. Inert Matter: this includes the amount of non-seed materials by weight. Soil particles, broken seeds, awns and short stems are items included in the percent inert matter.

Note: the amount of pure seed, other crop seed, weed seed and inert contents equals 100%.

The seed tag also bears information regarding the germination capability of the seed, which is tested under strict laboratory conditions for each species.

The percent germination indicates what percent of the actual seed itself will germinate (under optimum conditions). The date (month and year) of the germination test is included on the seed tag. For seed which travels as interstate commerce (essentially all our cool season turf grasses are from other states) the germination test information is applicable for a period of five months after the test month. For instate seed produced in Arizona (bermudagrass) the germination test is valid for nine months.

Special seed treatments (if applicable) must be noted on the tag as well. These treatments include any chemical or temperature treatments to break seed dormancy (potassium nitrate/cold storage, etc.). Any fungicide treatments to the seed would be included here as well.

If the variety has an application for, or has received a PVP (Plant Variety Protection) certificate, this too appears on the tag.

Blue Tag Certified Seed

This is the highest quality seed available. In order for turfgrass seed to achieve blue tag status, the following conditions must be met:

1. Fields have been planted with either approved foundation or breeder seed, or established with certified planting stock.
2. Variety is worthy of certification, or describable by the originator.
3. Production fields meet sanitation standards and are grown with proper isolation distances (from other plants of the same species).
4. The production fields have 0.03% or less off type plants.
5. Minimum standards for purity are met.
6. Other grass contamination limits are met.

These conditions when met, insure the buyer that the best quality seed is available to them.

Pure Live Seed

It is important to take into consideration the actual amount of seed which can be expected to germinate.

Two components of information on the seed tag allow you to do this. These two items are (1) the percent pure seed, and (2) the percent germination. If the seed is 90% pure, then the remaining 10% is not seed at all. If the germination is 85%, then on average 8.5 out of ten seeds will germinate. The remaining 1.5 out of ten seeds will not germinate. In order to find out how much "good seed" will at maximum "germinate," you must calculate the PURE LIVE SEED (PLS) INDEX. To do this, simply multiply the percent purity times the percent germination.

From our discussion example above...

PLS = % purity X % germination
(0.90) X (0.85)
= 0.76, or 76%

This means that 76% of the product by weight will germinate, under the best conditions. So a 50 pound bag of perennial ryegrass seed will have a PLS content of 38 pounds. Knowing this, the actual amount of seed required must be adjusted by the PLS content.

For example, a 3000 square foot lawn is to be overseeded at 20 lbs./1000 square feet with annual ryegrass. This quickly figures to a convenient 50 pounds of seed required. But, since the PLS content is 76% (0.76), we must now adjust and calculate how much of the actual product we need.

50 lbs. divided by 0.76 (PLS) equals 66 lbs.

We now need 66 pounds of seed which has a PLS index of 76% to seed 3000 square feet of turf at the 20 pound seed rate.

Both tall fescue and perennial ryegrass seed may or may not contain a beneficial fungus inside the seed. The seed is called the ENDOPHYTE. This endophyte fungus causes tall fescue and ryegrass plants in the lawn to produce natural chemical substances inside the plant. These chemicals repel above ground feeding insects. These include chinch bugs, flea beetles, armyworms, cutworms and aphids, etc. However, below ground insects (grubs) are not affected. The seed tag should say if the seed is either ENDOPHYTE ENHANCED or ENDOPHYTE FREE. If it does contain endophyte, it should say what percentage of the seed is infested. While endophyte enhanced seed is good from a lawn standpoint, it is unfavorable to use the same lawn seed for pasture. Do not establish a pasture from endophyte containing seed. Use it for lawns only.