University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Repair and Renovate Lawns Now

August 27, 1998

Now through early September is a great time for renovating and repairing lawns in northern Illinois. Start by determining the cause of the lawn decline and evaluating the site.

Many lawn problems originate from underlying heavy clay, compacted soils, and poorly drained soils that need to be corrected during renovation. Perhaps the soil is in good shape but lawn problems are due to pests, weather conditions, or poor management. Improved mowing, fertilizing, and watering may be all that's required for acceptable lawn quality in some cases.

Once the problem has been identified, the renovation process may begin. Think of renovation as fitting one of three levels: overseeding with little additional work; significant work, but allowing existing grass to remain; or completely removing the existing lawn and starting over.

The decision of which level to choose depends on how bad the lawn looks and what caused the problem. For example, if the lawn is just a little thin, overseeding with a quality lawn seed may be the answer. Seed may also be broadcast over thin lawn areas, but there needs to be good soil to seed contact. Rake away any dead grass or debris. Dethatchers or vertical mowers can also be used to tear out excess debris prior to overseeding.

Use of a slit-seeder is an ideal way to overseed lawns. In addition, slit-seeding could also be done directly through grass and/or weeds killed with the nonselective herbicide glyphosate (Roundup). All of these types of overseeding procedures do not require additional soil modification.

When soil problems exist under a lawn, there are ways to address them without tearing up the lawn. Core aerifying is suggested for problems such as thatch and soil compaction. Topdressing with a thin layer of quality soil can also be done. Aerifying and either overseeding or slit-seeding (breaks up cores) may be an ideal level of renovation for many lawns.

Unfortunately, some lawn problems, such as soil problems of severe compaction, high clay levels, or poor drainage, may require starting over. Remove existing grass or rototil it. High populations of perennial weed species may require the use of glyphosate. Thoroughly work the soil to a depth of 6 inches. Add amendments such as compost, rotted manure, organic topsoil, and peat. Then either seed or sod a new lawn.


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