If you find yourself unhappy with the condition of your lawn, consider taking steps now to make improvements. Purdue experts recommend one of three strategies in the Purdue Extension publication, Lawn Improvement Programs, the source from which I write this article.
The three strategies of lawn improvement to consider include fertilization and weed control, overseeding, or complete renovation.
If your lawn is just a little thin, perhaps fertilization and weed control can help its appearance. This strategy involves fertilizing in mid-September with a nitrogen-rich fertilizer product at a rate that will deliver 1 pound of nitrogen per 1000 square feet. A second fertilizer application can be made after the last mowing of the year at a rate of 1.0 – 1.25 pounds of nitrogen per 1000 square feet. If your lawn was especially thin, a third application can be added between those two applications in mid-October.
The final item in this strategy is to apply a broadleaf herbicide in mid-October to control weeds. A herbicide containing 2,4-D, MCPP, and dicamba will be effective on most weeds. Read and follow all herbicide label instructions.
The second strategy is overseeding. The optimum time to seed cool-season turfgrasses in Indiana is generally Aug. 15 to Sept. 15. In northern Indiana, we should err toward the earlier part of that recommendation. Mow the area to 1 or 1.5 inches, aerify the area, apply a starter fertilizer, then seed with a drop seeder or power overseeder (also called a slit seeder or slicer-seeder). Water the newly seeded area 3-4 times daily for the first few weeks to keep the soil surface moist. Mow at 1.5 inches 2-3 times, then increase mowing height at ½ inch intervals until the normal 2.5 to 3.5-inch mowing height is reached. A month following germination, fertilize with a nitrogen-rich fertilizer to provide a rate of 1.0 pounds of nitrogen per 1000 square feet.
The final option is a complete renovation. This option involves killing all vegetation with a non-selective herbicide, such as glyphosate. Allow a few days for the herbicide to work before moving on. Multiple applications may be needed to control tough-to-control grasses such as quackgrass or zoysiagrass.
After weeds are controlled, the ground should be worked by either aerifying the soil, tilling to 4 inches, or power raking (for significant thatch removal) followed by tilling. (Method will depend on your lawn’s conditions). Finish by raking the area smooth.
Before seeding, apply a starter fertilizer. Then, seed with a drop seeder or power overseeder. Lightly rake the soil to ensure seed-soil contact. Water the area 3-4 times daily, mow at 1.5 inches and move the mowing height up as described earlier. Seven weeks after germination, fertilize with a nitrogen-rich fertilizer to provide a rate of 1.0 pounds of nitrogen per 1000 square feet.
More information to help homeowners improve their home lawns is available in Purdue Extension publications, written by experts, at https://turf.purdue.edu/homeowner-publications/.You will find more detailed information about the above steps in the publication referenced earlier in this article. In addition, find publications that offer tips on establishing a turf area, maintaining a home lawn, weed control, disease control, insect control, and pesticide information.