Fall is the best time of year for lawn care

MP3 (September 3, 2015; 3:36 minutes)

Brown Patch left some yards looking brown and dead this year. If this is the case with your lawn, reseeding is necessary and fall is the best time to do it. Reseeding, fertilization, weed and thatch control, establishment of new lawns, and renovation of poor quality lawns should be done over the next few weeks.

The ideal time for planting grass seed to either establish a new lawn or renovate a poor quality one is September through mid-October in Missouri. During September grasses grow rapidly in the cool fall weather and have less competition from germinating weeds. The key to long term lawn quality is proper soil preparation. Soil should be tilled six inches deep. Incorporate organic matter, such as compost or peat, when tilling. If soil test results indicate a soil pH problem, sulfur or lime should be added at this time. After tilling smooth with a rake and apply starter fertilizer. Top quality grass seed will germinate better and be more disease resistant over time. Newly seeded lawns must have adequate moisture for seed germination and seedling growth. The seedbed and later seedlings must be kept moist for six weeks.

In early fall use a regular lawn fertilizer with N-P-K ratios of 3:1:2 or 4:1:2. For example, a bag may list 24-0-12 or 32-8-16. Amounts don’t need to be exact but should be similar to the suggested ratios. Hold off on applying "winterizer" fertilizers until late October or early November. More people are opting for natural lawn control, meaning they do nothing and let the lawn grow naturally, or they are using organic lawn care products. Whatever you choose to do is fine. I tend to fall in the middle. I don’t go overboard with fertilizers, but when I notice weeds I add some lime to the soil in the problem areas, and use a winterizer fertilizer in late fall. Lawns and other plants in shade grow slower and don't need as much nitrogen as plants in full sun. Therefore, shady lawns should be fertilized at half the recommended rate.

September and October are the best months to control perennial broadleaf weeds like dandelions and clover. In autumn the weeds prepare for winter by pulling nutrients and starches from their leaves into their roots. By doing this, they also draw herbicides into their root systems, thus more effectively killing the weed. Actively growing grass will quickly fill in the bare spots created after the weeds die.

Thatch is a build-up of living and dead grass roots and stems between the soil and green grass blades. The amount of thatch in the lawn may be checked by cutting three to four inches down into the grass with a shovel and lifting up a piece of sod. Thatch looks like a thick tangle of dark brown roots above the soil level. If thatch is greater than 1/2 inch, the lawn should be core aerated or dethatched in fall or spring. In lawns with a thatch layer over 3/4 inch thick you should aerate then topdress with a thin layer (1/8 to 1/4 inch) of soil or compost. Topdressing adds microorganisms that help breakdown thatch.

SOURCE: University of Illinois Extension. http://extension.illinois.edu/hortihints/0208e.html