Horticulture Turfgrass Specialist
Iowa State University Extension & Outreach
As the Iowa Turfgrass Extension Specialist, I am commonly asked which species I would choose for a new low-maintenance lawn. The answer is simple: Turf type tall fescue!
Tall Fescue is a cool-season grass that originated in Europe and was introduced into the United States during the early 1800’s. Tall fescue is slowly becoming a more popular choice in Iowa. It turns green in the mid-spring and maintains color into late fall. Tall fescue has the highest heat, traffic and drought tolerance of the cool-season grasses. It is well adapted to wet soils, partially shaded sites and is often used where low-maintenance lawn is desired. Tall fescue will form a deep root system that is tolerant of clay and alkaline soils. Tall fescue also has a moderate tolerance of cold temperatures, but is suitable for a majority of Iowa winters below U.S. Hwy. 20.
Tall fescue is medium to dark green in color and coarse textured. It is a bunch-type grass and forms a coarse, clumpy appearance when used alone. The new, improved turf type varieties have finer leaf texture, denser growth habit, and possess weak rhizomes (Photo 1, at bottom). Tall fescue has distinct longitudinal lines (veination) on the upper sides of its leaves. Key identifying characteristics also include rolled vernation and a pointed leaf tip.
Establishment and Interseeding
The best time to seed turf-type tall fescue in Iowa is between mid-August and mid/late September. However, successful lawns can be seeded as late as late-September in central Iowa and early October in southern Iowa. Late summer planting is preferred to spring seeding because seeds germinate and grow rapidly in the warm soil. The warm days and cool nights provide ideal conditions for seedling growth. Tall fescue seed germinates in five to ten days under favorable conditions. Another option is late-April to early-May seedings. Seeds are required to reach full maturity before the hot summer weather sets in making the establishment window narrow. Spring seed germination is slow when soil temperatures are below 50F. Weed competition from annual grass such as crabgrass, is also increased in the spring. The recommended seeding rate is 7-9 pounds per 1,000 sq. feet. A mixture of tall fescue (90-95%) and Kentucky bluegrass (5-10%) will help provide a uniform establishment. Damaged tall fescue areas are slow to recover and may need to be reseeded. For more information on tall fescue seeding, refer to Iowa State University Extension and Outreach publication “Establishing a Lawn from Seed” (PM 1072).
Tall fescue’s excellent drought and traffic tolerance, coupled with its bunch type growth, can cause a clumpy and uneven lawn when subjected to traffic and insufficient water. Should clumping become a problem, interseeding with additional tall fescue and provide temporary irrigation to regain adequate turf density. Common and improved types of tall fescue need interseeding every 3-5 years to reduce the clumpy appearance. Core aerification presents an ideal time for interseeding.
Mowing and Weeds
Tall fescue possesses a high growth rate, requiring more frequent mowing (every 5-6 days) in comparison to Kentucky bluegrass’s weekly mowing (Photo 2, at bottom). Tall fescue maintained at 3 inches yields rare weed problems. The improved varieties can handle lower mowing heights, but the weed pressure will increase. The presence of weeds is frequently a sign of a thin or weakened turfgrass. Weeds are often the result of improper cultural practices that stress the turfgrass, giving weeds a competitive edge. Weed control should start and end with the development of a dense, healthy, competitive tall fescue lawn. Proper tall fescue maintenance is the best weed control. For more information, refer to Iowa State University Extension and Outreach publication “Home Lawn Care: Weed Control” (PM 930).
Insects and Diseases
There are few insect and disease related problems unless the tall fescue is over-watered or over-fertilized. Older tall fescue cultivars are susceptible to brown patch disease, and occasional fungicide treatments may be required. The best way to prevent brown patch is to plant recommended cultivars and avoid over-watering and over-fertilization.
Masked chafers, Japanese beetles and May/June beetle are the most common grub species to attack Iowa lawns. Annual grubs such as masked chafers and Japanese beetles lay their eggs in the spring, and hatch in the summer. The larvae begin to feed on the root systems in August and these two species are commonly referred to as “fall grubs”, because a majority of damage occurs in the fall.
May/June beetle grubs are larger than Japanese beetles and the masked chafers and have a different life cycle (three-year grub). May/June beetle or June Bugs are frequently referred to as “summer grubs”, because damage happens in the summer.
Although rare in Iowa, sod webworms, cutworms, and other pests may also damage tall fescue lawns. Only treat pests when causing actual damage.
Reducing Inputs (Fertilizer, Aerification, Watering)
The advantages of tall fescue are its ability to handle heavy traffic, hot temperatures, and drought. The new, improved varieties have a fine texture and are generally more aesthetically pleasing. With the introduction of new tall fescue varieties, it is being considered in low-maintenance lawns with limited access to water. It is important to consider that while tall fescue can be used as an alternative to an adequate irrigation system; it would be a mistake on lawns where high quality turf is desired. The key point here is not to discourage you from using tall fescue, but instead to point out that a temporary irrigation is necessary regardless of species choice. Watering as little as three - five times during the summer may be sufficient to maintain a high-quality tall fescue lawn.
A single application of fertilizer in late October/early November containing 1.0 pound of nitrogen per 1,000 sq. ft. may be adequate for low-maintenance tall fescue lawns. Highly maintained lawns may need additional fertilizer in the spring (0.5 – 0.75lb./N per 1,000), September (0.75 – 1 lb. /N per 1,000), and a late October/early November (0.75 – 1 lb. /N per 1,000). To avoid over-stimulation of the grass, apply lower rates in the spring. Over-stimulation of grass may result in increased occurrences of the fungal disease known as leafspot. It will also deplete stored food reserves, making the grass susceptible to heat and drought stress. The number of applications depends on the desires/expectations of the homeowner, soil type, cultural practices, and other factors.
Thatch is an intermingled layer of living and dead plant material that accumulates above the soil surface and is usually not a problem in properly managed tall fescue lawns. Proper balance of thatch requires a combination of management practices. These include preventing thatch buildup by reducing plant growth, adding only the necessary nitrogen fertilization, consistent mowing, and mechanical removal of thatch.
A core aerator punches hollow tines into the soil and removes soil cores roughly the size of your index finger. Core aerating does not remove large amounts of thatch. Rather, it is an effective means of preventing thatch from developing and reducing soil compaction. Aeration and power raking services are available from professional lawn care companies and the machines can be found at rental companies.
Overall, the new turf type tall fescues offer a great low maintenance alternative to Kentucky bluegrass, and are recommended in non-irrigated lawns across central and southern Iowa. If Kentucky bluegrass or perennial ryegrass has failed due to the lack of water and summer droughts, it may be time to seed tall fescue (Photo 3, at bottom).
For more information on lawn care, the following publications are available at your county extension office, the Iowa State University Extension and Outreach online Store, or online at www.yardandgarden.extension.iastate.edu.
“Thatch Control in the Home Lawn” (PM 1127)
“Mowing Your Lawn” (PM 1213)
“Fall Tips to Ensure a Healthy Green Yard for Spring” (HORT 3021)
“Lawn Fertilization” (PM 1057)
“Home Lawn Care: Weed Control” (PM 930)
“Responsible Phosphorus Management Practices for Lawns” (PM 1447d)
“Establishing a Lawn from Seed” (PM 1072)
“Selecting a Grass Species for Iowa Lawns” (HORT 3023)
Figure 1: Turf-type tall fescue lawn on Iowa State’s campus. Picture courtesy of Nick Christians.
Figure 2: An example of tall fescue higher growth rate in comparison to kentucky bluegrass. Picture courtesy of Nick Christians.
Figure 3: In this picture, there is tall fescue surrounding our perennial ryegrass cultivar study. All of the ryegrass is nearly dormant, whereas the tall fescue around the outer edge of the trial remained green weeks longer. Picture courtesy of Nick Christians.