1. Clean debris from the turf. Maintain turf at a height of 2 - 3 inches and remove clipping debris. Mow again when turf reaches a height of 3 - 4.5 inches. Continue this regime throughout the year.

April

1. Apply water deeply and infrequently as needed. When precipitation is lacking supply about 1 inch of water per week in the spring and fall, and about 1.5 inches per week in the summer.

2. Check turf for leafspot and control if necessary.

3. Reduce thatch if the layer exceeds 0.5 inch. Core aerifiers or vertical mowers may be used; they can be rented at many large garden centers or rental outlets.

4. Use core cultivation machines to aerify turfs that have become compacted or that drain poorly.

5. In late April, apply preemergence herbicide for control of annual grasses in areas where these weeds are a problem.

May

1. Fertilize in early May with 1 pound of actual nitrogen per 1,000 square feet. Slow-release nitrogen forms are preferred.

2. Control broadleaf weeds if present.

June

1. In mid-June, fertilize with 1 pound of actual nitrogen per 1,000 square feet. Slow-release nitrogen forms are preferred.

2. In mid-June, make a second application of a preemergence herbicide.

August

1. Check for white grub larvae and control if necessary.

September

1. In early September, fertilize with 1 pound of actual nitrogen per 1,000 square feet. Slow-release nitrogen forms are preferred.

2. Reseed bare or thin areas with improved cultivars of bluegrass.

3. Check for leaf and stem rust on susceptible cultivars; control if necessary.

4. Reduce thatch if the layer exceeds 0.5 inch. Core aerifiers or vertical mowers may be used; they can be rented at many large garden centers or rental outlets.

5. Use core cultivation machines to aerify turfs that have become compacted or that drain poorly.

October-November

1. Apply postemergence herbicides for control of cool season annual and perennial broadleaf weeds. This is the preferred time for treatment.

2. In mid November, fertilize with 1 pound of actual nitrogen per 1,000 square feet. Quick-release nitrogen forms may be used.

3. Irrigate if necessary to insure turf is well hydrated going into winter.

Kentucky Bluegrass Cultivars

Many cultivars of Kentucky bluegrass are available. Recent turfgrass breeding developments have resulted in numerous improved cultivars that are resistant to fungal diseases, are dark green in color, and are adapted for growing vigorously under favorable conditions.
Here is a selected list of improved Kentucky bluegrass cultivars that have performed acceptably in Illinois. These Kentucky bluegrasses were irrigated to prevent stress, were mowed at 1.75 to 2.0 inches and received 2 to 4 pounds of nitrogen per 1,000 square feet per year.

The use of a blend of Kentucky bluegrass cultivars is recommended for establishing a turf in Illinois. A blend is a combination of several cultivars within a species. For best results, blend three or more of the above cultivars whenever seeding, or purchase sod that is comprised of several improved cultivars. Unlike a single cultivar, blends provide greater genetic variability. This variability improves disease resistance and the general adaptability of the turf to differing environmental conditions. Blending superior cultivars allows the desired features of each component to be incorporated and reduces the effect of specific weaknesses on general turfgrass quality.

Kentucky Bluegrasses for Reduced Maintenance Situations

When selecting Kentucky bluegrasses, it is important that cultivars be matched to the management intensity they will receive. Common Kentucky bluegrasses (*) often perform better under low management than high management, although they often lack the overall disease resistance of improved types. In contrast, improved Kentucky bluegrasses often perform better under high management than when grown under low management and usually are resistant to one or more turf diseases. These Kentucky bluegrasses have been reported to perform acceptably under low management (1#N/1000 sq. ft./year, no irrigation, high mowing).

Mixtures With Other Turfgrass Species

Mixtures are an alternative to single species blends. They are combinations of two or more species and are often advantageous because they increase the range of genetic diversity and adaptive potential. Some uniformity and quality is generally sacrificed by using such mixtures. The two most common mixtures are Kentucky bluegrass with fine fescue, and Kentucky bluegrass with perennial ryegrass.

Kentucky Bluegrass/Fine Fescue Mixtures

A bluegrass/fine fescue mixture is desirable for dry, shady locations, where there is a wide variation in the sunlight's intensity. Fine fescue does not perform well on sports turfs because of its weak rhizome system and slow recuperative potential. A traditional mixture consists of equal parts of Kentucky bluegrass and fine fescue. Shade-tolerant cultivars of bluegrass (for example, Bensun, Bristol, Eclipse, Glade, Nugget, Touchdown, and Victa) should be considered for the Kentucky bluegrass component of mixtures that are used in shaded areas.
The fine fescue cultivars that have performed acceptably in Illinois are listed below.

Kentucky Bluegrass/Perennial Ryegrass Mixtures

The rapid rate at which ryegrass seedlings are established makes a mixture of bluegrass and ryegrass desirable where quick cover is needed for erosion control, for aesthetic reasons, or where a midseason seeding is required.
The wear tolerance and soil compaction tolerance of these improved turf-type perennial ryegrass cultivars is considered good to excellent. Mixed with Kentucky bluegrass, these cultivars may be satisfactory on sports turf and other areas of heavy traffic. Overseeding on athletic fields and golf courses may be done with perennial ryegrass/Kentucky bluegrass mixtures. However, the recuperative potential of perennial ryegrass falls below that of Kentucky bluegrass. Furthermore, ryegrasses do not tolerate extremes of heat, cold, or drought as well as bluegrass. Ryegrass should never compose more than 20 to 25 percent of the seed mixture because of the strong competition with Kentucky bluegrass during the establishment period. The perennial ryegrass cultivars that have performed acceptably in Illinois are listed below.