By Joe Julian, Extension Agent Horticulture/Entomology
Where oh where has my green lawn gone?
A lot of Colorado homeowners ask that question this time of year, as they survey the damage to their lawns from a summer of insects, disease, drought, and dogs.
Fall is a good time to reseed bare spots in the lawn, no matter what their cause.
Before seeding, remove rocks, twigs, branches, and other debris from the lawn. Mow the grass shorter than usual, approximately one-half inch high to allow light and water penetration to emerging seedlings.
Loosen the dirt, especially important for Colorado's clay, cement-like soil. This allows seedlings to penetrate the ground and establish a strong root system. The amount of seed to apply will vary depending on variety, but a general rule is 1 1/2 pounds seed per thousand square feet. Before planting seeds, rake a high phosphorous fertilizer into the soil. The phosphorous will help establish a strong, healthy root system to encourage winter survival. Cover the seed with one-quarter inch mulch of peat moss or grass clippings that have not been treated with herbicides.
Next, a critical step: Water 3 to 4 times a day, until the seedlings are established, for about 2 weeks. Mow the reseeded area when plants have grown 3 to 4 inches tall.
Use a mixture of grasses when reseeding bare spots. A mix of various fescues, perennial ryegrass, and annual ryegrass works well. Creeping red fescue and chewings fescue establish quickly, tolerate cold, and adapt to drought and poor soil conditions. Creeping red fescue varieties include Flyer, Ruby and Shademaster. Chewings varieties include Atlanta, Banner, Mary, Shadow and Waldorf.
Perennial ryegrass varieties also establish quickly and are compatible with a Kentucky bluegrass lawn. This ryegrass also tolerates wear well and does not accumulate thatch, a major cause of lawn decline. Some varieties include Pennant, Pennfine, and Delray. Trenton and Park are 2 Kentucky bluegrass varieties that do well for thinning lawns. These are vigorous growing grasses with the sod-forming qualities necessary to fill in bare spots. Annual ryegrass establishes quickly and sometimes is used with perennial varieties. It will cover a bare spot immediately while the perennial grasses are establishing a root system.
Many seed companies, nurseries, feed stores, and department stores sell grass seed mixtures for lawn repair.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010