Get an Early Start on Spring Seeding

Home lawns are best established in the fall of the year around early September. However, there are times when fall seeding is impossible, such as in the construction of a new home or your attempt at fall seeding may have failed. The next best solution for the establishment of cool-season grasses is early spring seeding.

Techniques can vary depending on which month your spring seeding occurs. The old remedy of seeding prior to a snowfall does warrant some credibility if done at the right time, usually late winter or early spring. This procedure will work from late January through February if there is an excellent chance of getting the seed down to the soil surface. Melting snow will mud-in the seed just enough to achieve good seed/soil contact and germination. This is not necessarily the best procedure; however, germination rates should be sufficient to improve a thinned stand of turfgrass.

A second option is to broadcast seed on mostly bare soil that may have been tilled or loosened the previous fall. This can be done through the month of February when weather conditions will still bring forth a series of freezing and thawing periods. Freezing and thawing of bare soil produces small, ice-forming peaks and ridges in the surface of the soil creating cracks and crevices for seed to fall and eventually cover with soil. Germination rates for this type of seeding are very good and this allows seed to establish very early offering some competition against summer annual grasses and broadleaf weeds.

After the final thaw, normal spring seeding practices can involve two procedures. The first includes complete tillage of the area being seeded; however, this requires drier conditions for the soil to work. Over-seeding on freshly tilled, graded soil offers a perfect seedbed and only requires minor raking or dragging to work the seed into the soil. Germination should be very good for this application. Straw may be needed to help hold the soil and serve as a little mulch until germination begins. One bale of straw per 1,000 square feet is recommended on freshly tilled soil.

Spring seeding with a power-seeder or slit-seeder will plant turfgrass seed without the need for complete tillage. These can be rented at most rental or hardware stores for a nominal fee. They can be used for complete renovation jobs as well as partial renovations on thinned out areas of your lawn. They simply drop seed into a powder seedbed or actually plant the seed into shallow furrows on 3-inch centers. Achieving good seed to soil contact is the most effective way to get complete germination of your seed. These procedures generally do not require the use of straw.

With these two types of equipment, set the seeding rate in half and work the area in two directions. This application method will distribute seed more evenly and produce a dense canopy.

Seeding rates for Kentucky bluegrass should be two to three pounds per 1,000 square feet. Seeding rates for turftype tall fescues should be seven pounds per 1,000 square feet. Mixtures of tall fescue/Kentucky bluegrass in a 90/10 ratio should be seeded at six to seven pounds per 1,000 square feet.

Spring rains bring on summer annual weeds, grasses and broadleaves. Therefore it is critical to control these weeds with spring seeding and eliminate any competition for light, water and nutrients. Keep in mind that spring seeding does not allow the use of most preemergent herbicides (crabgrass preventers) for annual grass and broadleaf weed control. However, there are two herbicides that are available.

Tupersan (siduron) can be applied at any time seed is planted, but is best with applications during the last week of March through the first two weeks of April. This product can be purchased at local garden centers in granular formulation. It is a short residual product and requires two applications – one at time of seeding, and a second six to eight weeks later. This will insure excellent control of summer annual grassy weeds, such as crabgrass.

Dimension herbicide (dithiopyr) is a product that can be used for summer annual grassy weed control (crabgrass, foxtails, etc.) after a new stand of grass has had at least two mowings. Grass seed planted very early (March 1) could possibly receive two mowings by mid-April, therefore allowing for an application of Dimension. Dimension also works as a post-emergence product giving control of crabgrass after it emerges (one to three leaf stage). The window of application for Dimension herbicide is much wider than for Tupersan. Many other pre-emergent products (Ronstar, Barricade, Team, Pre-M, etc.) cannot be used for spring seeding since they require desirable turfgrasses to be well established.

The key to a quality lawn is to establish cool-season turfgrasses at the optimum times of the year. Standard practices usually recommend fall as the best time; however, spring is a second option that can yield an excellent lawn if done correctly.

Always remember that seed/soil contact is most important for both spring and fall. Spring seeding does require that added feature of weed control – those summer annual grassy weeds.

One final thought: after seeding, keep your soil moist, not wet. Always avoid puddles and runoff. When seeding Kentucky bluegrass or tall fescue, expect 10 to 14 days before seed germination.

Any questions about establishment of lawns can be directed to Brad Fresenburg at (573) 442-4893 or FresenburgB@Missouri.edu.

Brad Fresenburg Extension/Research Associate MU Turfgrass Research Center 573-442-4893