Planting a New Lawn

Sowing Seed

Once the site is prepared and the proper grasses have been chosen, it's time to plant the lawn. The decision whether to seed or sod involves a number of factors. Assuming planting is done properly, the end result of a healthy lawn should be the same.

Timing is critical to assure success when seeding lawns. Late summer to early fall is the ideal time to seed a cool-season lawn.

  • For northern Illinois: Early August to early September
  • Central Illinois: Mid-August to Mid-September
  • Southern Illinois: September

If a late summer to early fall seeding is not an option, April would be a second choice for seeding a lawn. Seeding in late spring through mid-summer often leads to problems as the summer heat slows or stops grass development of our cool-season grasses. Dormant seeding in the winter, occasionally done by professional groundskeepers, is difficult and thus not suggested for homeowners.

Seeding rates are found below. Exceeding rates may result in weak, spindly seedlings and potential disease development. Incorporate seed lightly into the soil surface for good seed-to-soil contact. This can be done by dragging a leaf rake upside down across a newly seeded site.

Suggested Seeding Rates for Lawn Grasses
Species in Seed Mix Rate (pounds/1,000 sq.ft.)
Kentucky bluegrass blend 1 to 3
Kentucky bluegrass/perennial ryegrass mix (80:20) 3 to 4
Kentucky bluegrass/fine fescue mix (50:50) 3 to 5
Tall fescue blend 6 to 9

Newly seeded grasses must receive adequate moisture to assure germination and early seedling survival. Putting down a light straw mulch can help prevent rapid drying and helps keep the soil in place until grasses are established. Use about one bale per 1,000 square feet.

Installing Sod

When sodding, purchase quality sod that has been freshly cut. Install promptly with a properly prepared firm soil bed, identical to what is done for seeding. Stagger edges in a similar pattern as laying bricks. Avoid stretching sod or having gaps between pieces of sod. Cut a small trench in the soil adjacent to the paved areas so the sod roots are below the paved surface and not exposed to the air. The soil bed should be firm so when walking you do not leave footprints. Those footprints, once covered in sod will remain and become small indents creating a bumpy lawn surface.

New sod should be watered thoroughly after installation. This initial deep watering ensures the soil below the sod roll has adequate of moisture. Sod acts like mulch over the soil, so homeowners often do not need to water as often as is thought. Continue to check the soil by lifting a corner of sod and feeling the soil and ensuing the soil is moist. Water should go down through the sod to moisten the soil underneath for good root development.

Mow newly sodded lawns on a regular basis so that no more than one third of the grass height is removed in a single mowing. A height between 2½ and 3 inches is suggested. Core aerating the lawn after the sod has firmly rooted to the soil will aid the development of a deep root system.

Don't fertilize newly sodded lawns until the next suggested time in the normal fertilizing schedule; May and September are key times. If fertilizing only once a year, fall is the preferable time. Avoid over-applying nitrogen fertilizer, especially in spring or summer.

Installing lawn seed using a drill or seed spreader
  1. Read the label to determine your seeding rate. Suggested seeding rates are in the table above.
  2. Seed at half the rate going east/west then repeat with the remaining half going north/south for guaranteed coverage
  3. Drag a leaf rake over the surface for seed to soil contact
  4. Lightly cover with straw mulch
  5. Irrigate often enough to keep the seed zone moist.
  6. Once the seed begins to germinate begin irrigate deeper with longer periods between waterings.
  7. Mow once grass has reached a height of 3-3½”
Installing lawn with sod
  1. Begin laying sod at far point from source to avoid foot traffic
  2. Stagger sod roles so seams do not lineup
  3. On steep hillsides lay sod across the slope starting at the bottom of the hill
  4. Water deeply at first and then monitor and water as needed to keep soil moist (not saturated)
  5. Ideally, sod will begin to root within 14 days. Tug on the rolls to know when they are rooted.
  6. Mow once grass reaches a height of 3 to 4 inches tall.


  • Larger selection of species
  • Turf develops in the environment in which it will ultimately survive
  • Lower cost than sodding


  • Timing of establishment critical
  • Slow stand development
  • May require reseeding
  • Rain or irrigation washes away seed
  • Weeds will be a problem
  • Initial watering is critical


  • ‘Instant lawn’
  • May be trafficked soon after planting
  • Dust, mud and erosion are reduced
  • May be planted anytime during the growing season
  • Weed-free


  • Typically, higher cost
  • Choice of species limited
  • Not produced in shaded environment
  • Large volume of water needed initially
  • Sod may shrink and weeds may invade
  • Speed of rooting varies with season