Warm days and cool nights are perfect for overseeding your whole lawn or just spot-seeding the weak areas. Natural moisture in the fall gives the seed a good chance to germinate, allowing the fragile new growth to take hold in the soil.

The first important step is to choose seed that will do well in the intended areas and then apply the correct amount. The second step is allowing the seeds themselves to come into good contact with the soil.

Blue grass and tall fescue are the most common turf grasses in Kansas. Tall fescue is the best adapted and requires the least water. Tall fescue is available in more than 160 cultivars or varieties. Local garden stores only carry a few. It is best to pick a blend of varieties and a blend mixed locally, as they will most likely follow local research and university recommendations. The label on each bag will show you the seed origin. The extra cost for good seed is a very wise investment. K-31 is the easiest and cheapest to find, but it earns the poorest ratings every year in the Kansas State University trials. K-31 also contains the highest percentage of “other grasses,” such as orchard grass, that are not desirable.

Sow seed uniformly. Use 6-8 pounds per 1,000 square feet on large dead areas and half that to thicken a thin lawn. Use the same application method discussed for fertilizer in last week’s article.

Overseeding the whole lawn or just spot-seeding the damage requires some soil preparation. The new seed must come into contact with the actual soil. Just throwing seed on top of thatch or thick grass will yield little. Hand-raking the spots is relatively simple. For larger areas, power equipment may be required. Power raking, even verticutting, can be damaging to the existing turf if not done very carefully. Core aeration is a much better alternative. This action relieves soil compaction, helps the thatch decompose and improves both moisture and nutrient retention. The little plugs of sod that core aeration leaves on top of your ground will break apart in a week or so.

Core aeration cannot be done with hard dry soil or muddy soil. A screwdriver should penetrate fairly easily to a depth of 4 inches, and soil (mud) should not stick to the blade when it is withdrawn. Do not fret about the fertilizer you have already applied. It is already watered in, and your second fertilizer application in November will easily make up for any losses.

Once planted, the area must be kept moist, not wet, until the seed germinates and starts to establish good roots. This germination will take 1-2 weeks and then another 23 weeks for a strong stand. Light watering on a daily basis may be required. Let the new grass get 3 inches tall before its first mowing.

Want to learn more about lawn care and other subjects? Then come to the Douglas County Extension Master Gardeners Fall Festival, which is 10 a.m.-2 p.m. Sept. 15 at the Douglas County 4-H Fairgrounds, 2110 Harper St. Admission is free.

Next week, we will deal with weeds.