To successfully establish a new lawn, the first decision is whether you’re going to sod, seed or sprig. This usually depends on economics and timing. Seed is initially less expensive than sod. However, successful establishment is more risky with seed than with sod, and if reseeding is necessary, the overall expense may be less with sod. Sodding practically eliminates erosion problems on steep hills or banks and also reduces the chance of pesticide and nutrient contamination from surface runoff. Seeding usually requires intensive weed control during the first year of establishment.
According to experts, seed should be used to establish lawns only in early fall or early spring, but sodding can be done just about any time of the year. If you live in a cool-season part of the country and you’re establishing the lawn in the spring, sodding is actually preferred.
Next, you have to prepare the site, and provide a plan to monitor and care for the site while the sod or sprigs take hold or the seed germinates. Cheating on pre-installation or post-installation will most certainly increase your chances of failure.
Okay, by the numbers:
1) To ensure the continuing health of the lawn you’re about to plant, first test the soil for composition, pH and existing nutrients. The test will indicate if organic matter such as peat moss or compost should be added to clay soils to improve drainage and aerification, or to sandy soils to help hold water and nutrients in the soil. It will also indicate whether lime is needed to raise soil pH or sulphur is needed to lower pH. If either phosphorus or potassium is needed, that will be indicated on the test as well.
2) Till the soil.
3) Rake the area to the finish grade just prior to seeding, making sure to clear it of rocks, clods and debris. Light rolling will indicate any low spots or other irregularities. A proper final surface will be firm enough to prevent ruts made by seeding equipment, but will be loose and crumbly so that seed easily can be raked into the top 1/4 inch of soil.
4) Allow for good drainage. Make sure the area is level and there are no low spots that will end in puddles. Make sure the lawn is sloping out toward the street, not toward the house. Slopes with a 1-foot drop in SO feet should be adequate, but should not exceed a 1-foot drop in 15 feet.
5) If seeding, apply a starter fertilizer first. Experts recommend that you work 30 lb. of 10-5-5 or 10-6-4 fertilizer, or 20 lb. of a 16-8-8 fertilizer (or the equivalent) per 1,000 sq.ft. The fertilizer should contain 30 percent or more of the total nitrogen as water-insoluble or controlled-release nitrogen.
6) If seeding or sprigging, choose a seed species, blend or mixture that will adapt and survive existing conditions. If seeding, apply at the rate recommended by your seed supplier. Apply the seed in two directions, at one-half the rate with each pass. A slit-seeding machine is preferred for incorporating seed into the soil and not just laying it on the surface. If you use a drop or rotary spreader, lightly rake or drag with the back of a rake, a flexible doormat, or chain-link fencing. A light rolling could be used to further press the seed into contact with the soil.
7) If sodding, the sod should be laid along an existing straight line (like a driveway). Tightly butt the sides and ends against each other without stretching the sod or overlapping pieces. Stagger the end joints in each row in a brick-like pattern. To trim corners and adjust the length of pieces, use a large, sharp knife.
8) If sodding, water the new sod within 30 minutes of installation if at all possible. If not, water to one inch as soon as possible.
9) For seeded or sprigged areas, mulch slopes with clean straw or salt hay to help reduce moisture loss. You should be able to see at least 50 percent of the soil through the mulch.
10) Water newly seeded lawns daily. They may need as many as four light waterings in a single day if conditions are dry and windy. Keep the seedbed moist, but not saturated, to a depth of one to two inches until germination occurs. Continue to water one to four times a day with light applications, approximately 1/8- to 1/4-inch of water per day.
11) Water newly sodded lawns one or two times a day. Begin irrigation immediately after laying sod. Sod should be watered so that the sod strip is wet as well as the top one inch of soil below the sod. The first irrigation requires about one inch of water. After watering, lift up pieces of sod at several locations to determine if it has been adequately irrigated. Continue watering one to two times a day with light irrigations to prevent wilting and to ensure a moist soil just below the sod layer. As sod becomes established and roots penetrate and grow in the soil, gradually reduce the frequency of watering but wet the soil deeper. After sod has been mowed two or three times, water deeply and infrequently.
12) As the seed germinates and reaches 1 to 1-1/2 inches, begin to raise the mowing height gradually, and remove clippings each time. After the new seedlings have been mowed three times, apply a light application (1/2 to 3/4 lb. per 1,000 sq. ft.) of nitrogen fertilizer. This application should be followed six weeks later with another application of 1 to 1-1/2 lb. nitrogen per 1,000 SQ. ft.