The best time of the year to plant new grass seed to fill in bare patches is, you guessed it, September. The combination of cooler temperatures and warm soils provides the best opportunity for recovery. September conditions allow for quicker germination of the seed, establishment before winter, and a mature stand better able to withstand the
coming summer stress conditions.

Success with planting grass seed is not as simple as broadcasting seed over the soil. There is an art and science to success. First, mow the lawn slightly lower than normal, removing most of the debris. The next step is to prepare the soil.

Soil preparation for seeding is accomplished by verticutting the lawn. A verticutter slices shallow grooves into the soil, into which the seed will fall, improving seed soil contact and germination. Be sure there is good soil moisture prior to verticutting so that the blades penetrate the soil uniformly. Once verticutting is done spread your seed, fertilize appropriately and water. The young seed should be up and growing within a couple of weeks.

Unfortunately, some people fail when seeding. The problem is usually not with soil prep or care, but with the selection of grass seed. There is very good grass seed on the market and there is also garbage seed.

Tall fescue and bluegrass are the only species of grasses that should be planted in Johnson County lawns. There are many good varieties of these species on the market available from local garden centers. They do a nice job of following K-State and other regional land grant University and Extension recommendations.

A good mix of tall fescue and bluegrass will contain three or four different varieties as each has desirable qualities. Often prepackaged bags or national brands add what I would call trash seed, either as fillers to help control price or give you a quick fix that does not last.

Here is the problem with blended mixes. In addition to the highly desirable tall fescue or bluegrass seed, they add grasses such as perennial ryegrass, annual ryegrass, creeping red fescue, Chewings fescue or other species that die out under our climate. These species cannot tolerate summer heat and drought. The result is they come up great in the fall and look good, but by next September all these inferior species will be dead and gone, leaving you back where you started with a thin, patchy lawn.

How do you know if you are purchasing quality grass seed for your lawn? It is as easy as just reading the ingredients label. Grass seed by law is required to have a seed label. This label is on the back and in small print and is comparable to a food label. It lists by percentage the grass species and varieties in the package.

Following my recommendation, the percentage of seed in the bag should be 99 to 100% tall fescue or bluegrass or a combination of the two. Any other species listed on the label is junk that will not survive for the long haul.

I have written biting words about grass seed, but it is difficult to tell someone they did all the right steps, but the use of low-quality seed mixes caused issues. Achieving a beautiful lawn is akin to life. You get out of it what you put into it. This saying can also be applied to grass seed.

Now get out there and show that lawn some September love, as it will start you on the path to success.

Dennis Patton is horticulture agent at the Johnson County K-State Research and Extension Office.