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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

Seeding a New Lawn

This article was published originally on 8/10/2011

 
A thick, healthy lawn is an important element in an attractive home landscape. The establishment of a new lawn requires careful planning and hard work. However, it is time well spent. The effort devoted to site preparation and turf establishment will be reflected in the quality of the turf for many years.
 
The best time to establish a lawn from seed is from mid-August to mid-September. Late summer planting has several advantages over spring seeding. The cool-season grasses will germinate quickly in the warm soil of late summer. The warm fall days and cool nights promote rapid turf growth. Also, few weed species germinate in fall so there is little weed competition.
 
The first step in planting a new lawn is the establishment of the rough grade. Remove construction debris, then fill in low spots and level off high areas. The ground should slope away from the foundation of the house, drive, and sidewalks. The rough grading should be done well in advance of seeding to allow settling to occur. 
 
At least 4 to 6 inches of good soil are needed to establish a lawn. If necessary, bring in additional topsoil or organic matter. Be sure the topsoil or organic matter is weed-free. Incorporate the additions into the top 6 inches of soil.
 
To determine soil fertility, conduct a soil test. Apply the recommended fertilizer, then incorporate it into the soil. Where a soil test has not been made, apply 10 pounds of a 10-10-10 or similar analysis fertilizer per 1,000 square feet and till it into the soil. The final step in soil preparation is hand raking the area. This is also the last opportunity to establish the final grade. Immediately prior to seeding, apply a starter fertilizer. A starter fertilizer is high in phosphorus. 
 
An important key to the successful establishment of a new lawn is the selection of the best suited turfgrass species for the site. Kentucky bluegrass is the best adapted turfgrass for sunny areas that receive at least 6 hours of direct sun each day. The fine-leaf fescues perform best in shady locations. (The fine-leaf fescues include creeping red fescue, hard fescue, chewings fescue, and sheep fescue.) Perennial ryegrass is often used in seed mixes because of its ability to germinate and establish quickly. 
 
For sunny locations, select a seed mix containing 80 to 90 percent Kentucky bluegrass and 10 to 20 percent perennial ryegrass. Select a mixture containing 50 to 60 percent Kentucky bluegrass, 30 to 40 percent fine-leaf fescue, and 10 percent perennial ryegrass in partially shaded sites. Heavily shaded areas that receive less than 2 hours of direct sun should be seeded with 100 percent fine-leaf fescue. 
 
Buy a high quality seed mix. Avoid grass seed mixtures containing a high percentage of perennial ryegrass, weed seed, or inert material. The higher quality seed will be more expensive, but there will be fewer problems.
 
Apply the seed with a drop-type seeder or by hand. The basic requirement is uniform distribution over the area. Sow half the seed in one direction; the remaining half should be applied at a right angle to the first application. After sowing the seed, lightly rake or drag the area. The seed should be covered to a depth of 1/8 to 1/4 inch. Roll the area lightly to insure good contact between the seed and soil.
 
To promote seed germination, mulch the area with clean, weed-free straw. Mulching materials help to conserve soil moisture. They also prevent soil erosion and crusting of the soil surface. Do not apply too much mulch, it may smother the emerging seedlings. Approximately 50 percent of the soil should be visible through the straw. One bale per 1,000 square feet of area should be adequate. Erosion control mats or blankets (available at garden centers and home improvement stores) are excellent options when sowing seed on steep slopes and other erosion-prone areas. 
 
After the ground has been mulched, water the area. Moisten the upper 1 inch of soil. After the initial watering, irrigate the area frequently and lightly. The objective is to keep the seedbed (upper inch of soil) continuously moist. Do not allow the seedbed to dry out during the germination period. It may be necessary to water 3 or 4 times daily on windy, sunny days. When the grass seedlings are 2 inches tall, water less frequently but deeper.
 
The new grass should be mowed when it is 3 inches tall. Make sure the mower blade is sharp. Mow at a height of 2 to 2.5 inches. Regular mowing through the remainder of the fall will help to thicken the turf.