Successful establishment of a lawn from seed is a critical component of creating a healthy lawn; however, at times good establishment can even be difficult for professionals. The potential of successfully establishing a healthy turf can be increased by paying attention to a few basic principles.
Soil testing should be the first step in any soil preparation for turf establishment. A soil test should be done well in advance of planting to allow time for adding any soil amendments that may be needed. This is the best time to add fertilizer, lime, and other mate- rials that may be needed. Rough grading of the existing soil or any new topsoil that was brought in is often necessary. In building construction, such as around new homes, where the top soil has been removed, 4 to 8 inches of topsoil should be placed on the site prior to establishment. Once the rough grading process has been completed, a starter fertilizer should be placed on the surface and not worked into the soil. A good choice for relatively fertile soils is a 12- 25-10 fertilizer applied at a rate of 5 to 8 pounds of fertilizer per 1,000 ft². In the case of less fertile soils, where P (phosphorus) levels are relatively low, a material like 18-46-0 applied at the same rate may be more appropriate.
The time of seed application depends upon whether the grass is a cool-season or a warm-season species. Warm-season grasses established in temperate zones should be seeded in the spring as soon as soil temperatures are high enough to achieve germination. Cool-season grasses are best established in the late summer or early fall. It is important to apply the seed using the correct seeding rate.
The appropriate seeding rate is generally listed on the bag of seed. The grass seed is generally seeded on the surface and then lightly raked into the soil.
The smaller the seed, the shallower it should be planted. Very small seeds like creeping bentgrass will need to be very close to the surface, whereas larger seeds like tall fescue can emerge from depths of one half to one inch. The seed should also be spread as uniformly as possible by hand or using a mechanical spreader.
One of the keys to successful establishment is proper irrigation. The critical time is just after germination when the root system is not developed well enough to obtain sufficient moisture from the soil. Frequent irrigation is particularly important on warm windy days when the soil surface can dry out in a few hours.
The use of mulch such as straw can also help maintain adequate soil moisture during establishment.