The blue-tinged green color and fine texture of Kentucky bluegrass, with its boat-shaped blades, make it the most popular lawn cover in North America. It actually thrives better in cool, moist climates with cold winters than it does south of its namesake state. Follow these tips for a lush, vivid lawn of Kentucky bluegrass.
1. Where and When to Sow Kentucky Bluegrass Seeds
Sow your seeds in the fall in a sunny area, or if your winters are mild, choose an area with sun and partial shade. Make sure that your lawn soil has plenty of organic matter and is well drained. Check the soil pH for acidity, as Kentucky bluegrass thrives in slightly acidic soil, with a pH near 7.0. If you are sowing a lawn for the first time into soil with a high clay percentage, till the area and add a layer of coarse gravel six inches below the surface to promote drainage. Seeds scattered over the surface take longer to germinate, so push them down about one inch into the soil. If you are laying sod patches, put these down in early fall, so the roots can become established before winter.
2. Fertilize Kentucky Bluegrass
Optimize the growth of Kentucky bluegrass with a program of regular fertilization. Upon seeding or laying sod, use a seeding fertilizer with phosphorus, and a lawn fertilizer high in nitrogen to promote root and grass blade growth. In late fall, before the first frost, apply a winterizing timed-release fertilizer with nitrogen and potassium. This helps the lawn survive deep soil frost, snow and ice. Maintain this feeding program annually to help thicken and spread your Kentucky bluegrass lawn effectively.
3. Mow Kentucky Bluegrass
Allow initial growth to reach five inches in height before mowing so the grass can spread and choke out weed growth. Mow Kentucky bluegrass regularly thereafter, at a maximum of three inches in height. Cease mowing bluegrass during mild drought periods in hot summer weather, and in the early fall, to allow carbohydrates to collect in the grass rhizomes.
4. Water Kentucky Bluegrass
Add water to seeds two or three times a day, using a low-pressure setting on the garden hose or sprinkler. Once leaf shoots appear, water just once a week. In summer heat, water twice a week or as needed between rainstorms. Allow the bluegrass to go dormant in high-heat conditions above 85 degrees F. (30 C), and water just the tips every two weeks.
5. Plant Other Grasses with Kentucky Bluegrass
Consider mixing in other perennial grasses such as ryegrass to help the lawn recover in patches of high wear. Fine fescue also blends well with bluegrass.
6. Pests and Diseases of Kentucky Bluegrass
Most pests and diseases affect bluegrass when it is suffering from drought, which weakens the roots and stems. Most insect infestations appear during hot weather so watch for white grubs, webworms and billbugs. Apply suitable insecticide when you see the first specimens. Mixed planting of ryegrass and bluegrass will prevent a blight called Fusarium, which whitens Kentucky bluegrass leaves and rots the roots. Choose bluegrass strains developed for greater resistance to leaf spot and rust.