Archive for September 5, 2008

Overseeding lawns

Richard Jauron, Horticulture Specialist at Iowa State University Extension, offers the following on overseeding lawns:

Healthy, well maintained lawns are attractive landscape additions.  Lawns in poor condition, however, are somewhat unsightly.  The poor condition of a lawn may be due to poor management, heat, drought, diseases, insects or other factors.  In severe cases, the existing lawn may have to be destroyed and a new one established on the site.  Lawns that contain over 50 percent desirable grasses can often be improved by overseeding.  

Overseeding is the sowing of grass seed into an existing lawn.  In Iowa, the best time to overseed a lawn is late summer (late August to mid-September).

Site Preparation

Good site preparation is necessary for successful overseeding.  If possible, identify and correct the problems causing the lawn to decline.  Overseeding may only be a temporary solution if these problems are not corrected. 

To reduce the competition from the established turfgrass, mow the lawn at a height of 1-1/2 to 2 inches.  Successful overseeding also requires good seed-to-soil contact.  Simply throwing or broadcasting seed over the lawn typically results in poor seed germination as much of the seed is resting on the thatch layer or soil surface.  Rakes, core aerators, vertical mowers, and slit seeders can be used to ensure good seed-to-soil contact. 

Overseeding Small Areas

Small areas can be prepared by gently raking the thin spots.  When raking, it’s necessary to break the soil surface without pulling out the existing turfgrass.  After raking, sow the seed by hand.  Then, work the seed into the soil by gently raking the areas a second time. 

Overseeding Large Areas

Large areas can be prepared by using a core aerator.  Core aerators are machines with hollow metal tubes or tines.  They remove plugs of soil when run over the lawn.  To prepare the site, go over the lawn three or four times with the core aerator.  When finished, there should be 20 to 40 holes per square foot.  Apply the seed with a drop seeder.  Afterward, drag the area with a piece of chain link fence or drag mat to break up the soil cores and mix the seed into the soil. 

It’s also possible to prepare the site with a vertical mower.  When run over the lawn, the knife-like blades of the vertical mower slice through the thatch and penetrate into the upper 1/4 to 1/2 inch of soil.  One or two passes should be sufficient.  Afterwards, remove any dislodged debris from the lawn.  Sow grass seed over the lawn with a drop seeder.  Work the seed into the soil by again going over the site with the vertical mower. 

Large areas also can be overseeded with a slit seeder.  A slit seeder makes small grooves in the soil and deposits the seed directly into the slits. 

Core aerators, vertical mowers and slit seeders can be rented at many garden centers and rental agencies.  If you would rather not do the work yourself, many professional lawn care companies can overseed your lawn. 

Post Seeding Care

Keep the seedbed moist with frequent, light applications of water.  It’s usually necessary to water at least once or twice a day.  Continue to mow the lawn at a height of 1-1/2 to 2 inches.  Mow the lawn frequently to reduce the competition from the established turfgrass.  When the new seedlings reach a height of 1-1/2 to 2 inches, gradually increase the mowing height over the next several weeks.  The final mowing height should be 2-1/2 to 3 inches.  Approximately six weeks after germination, fertilize the lawn by applying 1 pound of actual nitrogen per 1,000 square feet.  

When properly overseeded, a thin, scruffy-looking lawn can be turned into a thick, lush lawn in just a few weeks. 

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What is permaculture?

Backyard Abundance and Field to Family are sponsoring a free “What is Permaculture?” event to show residents how they can use Permaculture principles to help our environment in their own backyard.

 

Two yards will be visited: one is undergoing a complete ecological landscape design makeover and the other features an established vegetable and herb garden. At each yard, experts in our community will provide an overview of how to:

  • design an environmentally friendly landscape
  • choose the correct plants
  • design a rain garden
  • install a rain barrel
  • start a new garden bed
  • create compost
  • grow mushrooms

 

Both yards and the features within them are designed based on Permaculture principles and patterns. Permaculture (permanent agriculture) provides a framework and methodology for consciously designing and maintaining urban ecosystems that have the diversity, stability, and resilience of natural ecosystems. It is the harmonious integration of landscape and people, providing food, energy, shelter, and other material and non-material needs in a sustainable and ethical way.

 

The event is Sunday, September 7 from 1-4:00 pm. Carpools will be taken from New Pioneer Food Co-Op, 22 S. Van Buren St., Iowa City. People can also drive individually.

 

For arrival times at each yard, directions, and more information, visit the Backyard Abundance web site at http://www.BackyardAbundance.org or contact Fred Meyer at 319-358-7665.

 

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