Lawn Care Checklist
Fertilize lawns for a final time early this month with a slow-release organic product high in nitrogen. Chicago area soils are naturally high in potassium and phosphorus, and most lawns don’t require more. This nitrogen application will help lawns retain green color longer in winter and color up faster in early spring.
Try to avoid walking on frozen turf; this breaks grass blades.
Mow grass for the last time and cut the grass quite short. This helps prevent winter injury and reduces snow mold fungus. Don’t mow if grass has gone dormant. Mold and fungus can develop in shady grass areas if excess garden debris or fallen leaves are left on grass over winter.
Avoid walking on frozen grass. This breaks grass blades and mats down turf, creating paths.
Crab grass control can be spread on lawns in early to mid-April before weeds germinate. For severe problems, a second application might be necessary in early June.
Mow lawn at 2 to 2½ inches, removing one-third or less of the leaf blade. Leave grass clippings on the lawn to return nutrients to the soil, or add them to compost heap. Rake clippings slightly if they are heavy and wet. If you are applying grass seed, do not use a pre-emergent weed killer in the same area.
Fertilize lawn in mid-May if necessary. Late fall is a preferable time to fertilize. Monitor for weeds and hand pull or spot treat accordingly.
Cool-season turfgrass should be mowed to a height of 2 to 3 inches. This height can be raised during hot, dry periods or when turf is stressed due to disease, insects, or drought. A general rule of thumb is not to remove more than one-third of turf at one time.
Seed bare areas of turf with an appropriate grass seed mixture. Keep newly seeded lawns moist until seeds germinate. Do not allow the grass to become overly dry for the first year and limit excessive foot traffic. Begin mowing when the grass reaches a height of approximate 4 inches.
Do not fertilize your lawn in hot weather. The best time to fertilize is fall.
Established turf requires approximately 1 inch of water per week to keep grass green and actively growing. Lawns that are allowed to become dormant and brown usually recover nicely as precipitation increases in the fall. It is best to water early in the day, which will decrease the occurrence of turf disease.
Do not fertilize lawns in summer. Early fall is the best time to apply a 3-1-2 ratio fertilizer.
During drought or times of water conservation, turf will go dormant, but the grass plants’ crowns will remain alive with only 1 inch of water.
Mow grass at a high level in hot summer, 2½ to 3 inches. Grass clippings can be left on the lawn and gently raked to avoid clumping.
Avoid using herbicides in hot weather. Always read directions carefully. Pull out annual weeds, such as crabgrass, before they go to seed.
Mid- to end of August is the best time to seed bare areas of lawn, overseed thinning grass, or lay down sod. When seeding lawns, use grass seed appropriate to your site. The best choice for most lawns in northern Illinois is a mix of Kentucky blue grass, perennial rye, and fescue seeds. If seeding in a shaded area, purchase a shade-tolerant mix. Cultivate soil down to a few inches and broadcast grass seed and starter fertilizer according to package directions. Cover with loose straw to prevent wind or bird damage to seeds. Keep soil moist until seed germinates.
To overseed an entire lawn, consider hiring a professional or renting a slit-seeding machine that automatically drops seed into small slits made by the machine.
Before laying sod, prepare soil as above. Water deeply to encourage roots to grow downward into new soil bed. Purchase sod grown on soil similar to your own. Let grass grow a bit longer before mowing. Set mower at proper height so that no more than one-third of the grass blades are removed.
Refrain from fertilizing lawns until September.
Annual white grub damage will begin to show up this month as browned-out areas of turf that pull back easily, like a carpet. Grubs chew grass roots, resulting in turf that lifts up. Minor damage is usually not cause for treatment. Pull back turf and count grubs (white C-shaped larvae with black heads); 10 to 12 per square foot is considered enough to treat. Recommended chemical products vary in their application time. Many gardeners wait until the third week of the following June to apply imidacloprid. If possible, try to avoid using strong insecticides if damage is light. If necessary, treat affected areas rather than entire lawn.
Homeowners might notice a chewed-up appearance to their lawns if grubs are numerous. Skunks, raccoons, and birds will tear up grass searching for grubs, especially at night, sometimes doing more damage than the grubs themselves.
In times of drought, excessive heat, or water restrictions, grass can go dormant. The grass will turn yellow but the crown of the plants will remain alive with just a half-inch of water over several weeks. Grass will green up as soon as normal rainfall returns.
Early this month, entire lawns or bare patches may be seeded with appropriate grass seed mix.
Grubs chew grass roots, and they may be present if your turf begins to brown and lifts easily off the ground. Minor damage is usually not cause for treatment. Pull back turf and check for white, C-shaped larvae with black heads. If more than 10 to 12 grubs are present in a square foot of soil, treatment is advised. Chemical controls vary in their timing. Homeowners can spot-treat small areas immediately with a recommended control or, wait until the third week of next June to apply imidacloprid. As temperatures become cooler in fall, the grubs will move further down in the soil, making them out of reach of chemicals.
Consider core-aeration of lawn, if not done this year. Professional lawn services can provide the equipment (and the service itself) to remove plugs of soil and grass at regular intervals over entire lawn. Plugs are left on lawns to decompose. Core-aeration is recommended to help rectify compacted soil, heavy thatch accumulation, and poor drainage. Avoid this procedure when soil is quite wet.
Midmonth is a good time to apply fertilizer to lawns. Choose an organic product or a synthetic fertilizer with a 3-1-2 or 4-1-2 ratio. Moderate temperatures this month along with cool nights and adequate rainfall will spur grass growth, making September a good time to feed turf.
If not done in September, fertilize lawns with a slow-release, organic fertilizer with a 4-1-2 or 3-1-2 ratio. The final application of high-nitrogen fertilizer should be applied in November. This late treatment will help the grass to green up faster in spring.
Continue to mow lawns at 2½ to 3 inches. Grass clippings may be added directly to compost heap. Avoid adding soaking wet clippings to compost.