For cool season grass lawns: bluegrass, fine and tall fescue, perennial rye
Barbara J. Bromley, Mercer County Horticulturist 2004
After a long dreary winter there are many yard maintenance and planting projects to occupy a gardener’s time. The lawn is just one of them. Surprisingly, and despite the proliferation of ads to the contrary, most major lawn chores including renovation and dethatching are best done in late summer. (It’s called “Labor Day” because that’s when you work on your lawn!) Mowing is the most universal spring chore. Reseeding small bare spots, fertilizing, some pest control applications, and aerating may be done in spring. The following are some considerations and chores for spring and early summer on cool season grass lawns. (Zoysia, a warm season grass, is maintained differently.)
- SET YOUR APPEARANCE STANDARD FOR THE LAWN. IS PERFECT NECESSARY? /LI>
- “Perfect” is a nearly impossible standard for a lawn, especially if pesticides are not used regularly. Accepting a few weeds or a lawn with different shades of green is far more practical.
- SET YOUR MAINTENANCE STANDARD FOR THE LAWN: HIGH, MEDIUM OR LOW.
- How much time and money do you plan to spend on the lawn? Is it do-it-yourself or service company?
- The high maintenance lawn (HML) characteristics:
- bluegrass and/or perennial ryegrass
- has a sunny exposure
- is usually irrigated regularly
- may have the clippings removed, but not necessarily
- is generally fertilized four or more times per year: 4-step programs, commercial lawn service
- needs to be mowed at least once per week depending on the chosen mowing height
- pesticides (herbicides and insecticides, sometimes fungicides) are usually applied on a schedule.
- The medium maintenance lawn (MML) characteristics
- is tall fescue, some lower maintenance bluegrasses, fine fescues, or a combination of bluegrass and fine or tall fescue. May have small amount of perennial rye initially.
- may be sun or partial shade
- is seldom irrigated
- is fertilized two (or three if clippings are removed) times per year in May and September, or September and November.
- has the clippings left on the lawn (usually)
- pesticide applications are generally limited to spot treatments
- mowing frequency is generally about once a week in periods of rapid growth
- mowing height is 3 inches or higher.
- The low maintenance lawn (LML) characteristics
- is fine fescues or unimproved bluegrasses or tall fescues or mixtures. Probably includes non-grass plants.
- is in sun or partial shade
- is never irrigated
- clippings are always left
- is fertilized once a year (preferably September) or not at all
- pesticides are not used
- mowing is “as needed.” Mowing height should be 3-5 inches.
- FERTILIZING and LIMING
- Have a SOIL TEST run as early as the soil is frost-free if a test has not been run in the last five years. Soil mailers are available for $10 at Cooperative Extension offices in each county.
- Fertilize in spring as recommended by the soil test and maintenance program: HML in April and late May, MML in mid-May or not at all, LML not in spring at all. (The most important fertilizing for all maintenance levels is in September.)
- Summer fertilizing is generally not recommended for any cool season grass lawn. Irrigated HML can be given a half-rate application of a 100% organic nitrogen source in summer to maintain color.
- Lime all maintenance level lawns as recommended by soil test. Do not apply limestone every year out of habit. Maintain the pH between 6.0 and 6.5. Use pulverized or pelletized limestone if the pH is below 5.8. Use granular, pelletized, or pulverized limestone if the pH is 5.8 or higher.
- MOWING
- Mow as often as is necessary to remove no more than 1/3 of the blade. Maintain the highest practical mowing height for the lawn. 2 ½ inches (spring) and 3 ½ inches (summer) should be minimum on all cool season turf. Keep mowing height over 3 inches when temperatures stay consistently above 75° F.
- Sharpen blades every 25 hours of operation or after hitting an obstruction of any kind.
- Leave clippings on the lawn. Get a mulching mower or mulching blade.
- Don’t mow when the grass is wet to reduce disease spread. Do not mow when grass is seriously drought stressed or dormant to prevent damage to the crown.
- PEST CONTROL: WEEDS, INSECTS, DISEASE
- Think before using a 4-step fertilizer and pesticide application program for lawns. Why apply pesticides that are not warranted?
- Crabgrass prevention (pre-emerge) materials are applied by mid-April and may need to be reapplied four to six weeks later to extend protection. Dense turf will not harbor crabgrass, so these controls are not needed if lawn is reasonably thick with few bare spots. Corn gluten products will substitute for pre-emerge crabgrass control and nitrogen fertilizer.
- Broadleaf weed controls are applied as a spot treatment when weeds are noticed. Avoid “weed and feed” products unless the turf was renovated in early fall or if the lawn is very thin. Identify the weed first, then select a management option. Ignoring weeds, applying 20% white vinegar to the center of each weed or cutting it out with a knife and herbicides are all options. Some weeds, such as dandelion, are best controlled in October.
- Insect controls are applied when insects are active (surface feeders such as chinch bug and sod webworm) or as preventers (grubs) if an untreated problem existed the year before. Grub control may also be applied in March or April or in mid-August/early September for an active population
- Never apply herbicides (or any pesticide) on a windy day or just before heavy rains.
- NEW-SEEDING OF DAMAGED OR BARE AREAS
- Small areas can be sodded or over-seeded early. Save large-scale renovation projects for late summer.
- Seeding can be done from mid-February to mid-March on thawed ground that will freeze again at night (“honeycomb” seeding). Ensure good soil contact. The seed will germinate when the soil temperature reaches about 50° F. Seed can be spread until early May or so, but the problems with heat, drought and weed competition may make the results unsatisfactory. (Late August and September are best for seeding.)
- Select grasses based on sun or shade conditions, amount of use, soil drainage, and maintenance program. Examples: Kentucky bluegrass and perennial ryegrass do best in full sun and high maintenance and adapt well to high use, such as soccer and volleyball. Fine and tall fescues are adapted to reduced light, but grow in full sun and drought conditions. Fine fescue does not tolerate foot traffic well, but established tall fescue does. Use Poa trivialis, rough bluegrass, in damp shade.
- Use blends of grass species and mixes of varieties. Blends and mixes lend much more diversity to a lawn and reduce the impact of insect and disease infestation.
- Choose pest-resistant grasses. The varieties of perennial ryegrasses and fescues that contain endophytes are resistant to some surface-feeding turf insects and some diseases.
- Consider alternatives to turf grasses in very shady sites. There are mosses, ground covers, and mulches that are better adapted to very shady locations than grasses.
- IRRIGATION
- Lawn grasses, with the exception of perennial rye, do not have to be watered to survive moderate droughts. Supplemental irrigation may be needed to prevent dormancy and keep the grass green through the season.
- Lawns should be watered in early morning to reduce the length of time the grass blades are wet and therefore helps reduce disease problems. Grass plants will make a more efficient use of water and there will be reduced water loss to evaporation. Lawns need about 1 inch of water per week on clay soils and 1 ½ inch on sandy soil.
- Water deeply and infrequently, not shallowly and often. Irrigation systems are often set to go on every other day for 20 minutes per zone. This procedure will not stimulate as deep a root system on heavy soils as will watering deeply just once every 5 to 7 days.
- AERATION AND DETHATCHING
- Aerate before applications of lime, fertilizer, or weed preventers or killers. May be done several times a year, but opens the soil to weed invasion if herbicides are not used. Best in late summer, but may be done in spring.
- Dethatch if lawn has over ¾ inch of thatch, but this is best done in late summer or fall.
- TURFGRASS REFERENCE INFORMATION
- County Cooperative Extension staff, Master Gardeners, turf professionals, books, magazines, fact sheets, Internet sites. Ask for credentials including past training and a pesticide applicator’s license.
- BOOKS
Carr, Anna et al, 1991, Chemical-Free Yard & Garden. Emmaus, PA: Rodale Press.
Gussack, Eva and Fs. Rossi, 2001, Turfgrass Problem: Picture Clues and Management Options, NRAES
Hill, Lewis and Nancy, 1995, Rodale’s Successful Organic Gardening Lawns and Groundcovers. Rodale Press.
Mace, Alice (Ed.) 1985, Ortho Books All About Lawns. Chevron Chemical Co.
Schultz, Warren, 1989, The Chemical-Free Lawn. Rodale Press.
Uva, Richard H., JC Neal and JM diTomaso, 1997, Weeds of the Northeast Ithaca, NY: Cornell Univ. Press
Walheim, Lance, 1998, Lawn Care for Dummies, IDG Books Worldwide, Foster City, CA
- RUTGERS COOPERATIVE EXTENSION TURF-RELATED FACT SHEETS (most are free):
| FS102 Your Lawn and Its Care | FS684 Turf Seed Selection for Home Lawns | |
| FS104 Steps to an Instant Lawn | FS738 New Jersey Seed Std. for Sod Certification | |
| FS108 Renovating Your Lawn | FS740 Thatch Management in Turf | |
| FS385Broadleaf Weed Control in Cool Season Turfgrasses | FS766 Lawn Fertilizer Spreader Calibration | |
| FS184 Chemical Control of Turfgrass Diseases | FS797 Soil Testing for Home Lawns and Garden | |
| FS210 Japanese Beetle | FS814 Managing Diseases of Landscape Turf | |
| FS389 Min. Waste Disposal: Grass Clippings | FS829 How to Protect Water Quality and Have a Beautiful Lawn | |
| FS426 Moss in Lawns | FS839 How to Calculate the Amount of Fertilizer Needed for Your Lawn | |
| FS555 Best Manage. Prac. for Watering Lawns | FS921 Conserving Water on Home Lawns and Landscapes in New Jersey | |
| FS584 Seeding Your Lawn | FS1007 Sod Webworms | |
| FS633 Fertilizing the Home Lawn | FS1008 Hairy Chinch Bug | |
| FS635 Managing Soil pH for Turfgrasses | FS1009 White Grubs | |
| FS735 Nutrient Sources for Growing Plants by the Organic Method | FS1015 Billbugs |
E233 Crabgrass and Goosegrass Control in Cool Season Turf (price: $1.00)
Publ. No. EO37 2003 (updated each year) Pest Control Recommendations for Lawn and Turf Areas (price: $3.00)