How to Care for a Lawn in September

Lawns need watering, even in late summer.

Late summer is often the height of the lawn care season. In September, the cooler temperatures encourage the grass to grow after being dormant in the summer heat. While less irrigation may be needed as the weather cools down, it is now the prime season for fertilizing and reseeding the lawn as well as cleaning up debris from plants preparing for winter dormancy. Taking good care of your lawn in September and into fall ensures it returns lush and green in spring.

Things You'll Need

• Lawn mower
• Fertilizer
• Fertilizer spreader
• Herbicide
• Power rake
• Aerator
• Grass seed

Instructions

1. Mow the lawn when it reaches 3 to 4 inches in height, mowing as often as necessary throughout the month of September. Set the mower blades between 2 and 2.5 inches in height as this is the prime height for healthy lawn growth.

2. Fertilize with a nitrogen fertilizer at the beginning of September when temperatures are still warm. Apply 1 lb. of actual nitrogen per every 1,000 square feet of lawn. Fill the fertilizer spreader with the amount of fertilizer required and set the spreader to the rate recommended on the fertilizer bag.

3. Apply a broadleaf weed herbicide in fall, following label directions for exact application amounts and methods. Using a herbicide in September is more likely to kill problem weeds than a spring application, as the weeds are more likely to absorb the herbicide in fall.

4. Remove thatch from the lawn if it is deeper than 1 inch. Heavy thatch makes the lawn more prone to winter fungal diseases. Use a power rake or a dethatcher to strip the thatch without damage to the lawn. Remove only 1/2 inch of the thatch layer from the lawn.

5. Aerate the lawn with a lawn aerator after you have dethatched the lawn, if necessary. Rent aerators from hardware stores and follow the directions given for the particular make and type of aerator. Generally, aeration plugs are made every 3 to 4 inches throughout the lawn. Aeration allows more nutrients and water to reach the grass root zone.

6. Seed the lawn at the beginning of September so the new grass has time to establish before winter. Use the same type of grass seed as is currently growing in your lawn. Spread the seed over bare areas or over the entire lawn at the rate recommended on the package. Water twice daily until the new grass has become established, usually within two months of planting.

7. Water one to two times a week, applying about 2 inches of water to the lawn at each irrigation. Water in the morning so the moisture has time to soak into the soil before it evaporates. Avoid evening watering as the moisture sits on the grass blades which leads to disease and fungus.

Tips & Warnings

• Raking leaves and debris as they fall on your lawn helps prevent thatch build-up on the lawn.

• Dull lawn mower blades damage grass. Sharpen them twice a year--once in spring and again at the beginning of September.

References

• University of Illinois Extension: Fall Lawn Care Guide