Lawn Grass Cultivar Selection

When considering the establishment of a new lawn, the first factor that should be considered is which grass species (such as Kentucky bluegrass, perennial ryegrass, fine fescue, or tall fescue) to plant. After selecting the species, consider the appropriate cultivars or varieties within the species Cultivars are plant varieties that have been cultivated and selected by breeders for various beneficial reasons. As with most cultivated plants, each turfgrass species has a number of cultivars, varieties, or hybrids, each of which have subtle genetic differences.

Several factors should be considered when choosing turfgrass cultivars. Plant those that are best adapted to the conditions where the lawn is to be located. Shady, wet, poorly drained areas, or regions of the lawn with poor soil, pH extremes, drought susceptibility, etc. all require careful cultivar selection. Turfgrass cultivars with resistance to diseases should also be included in the blend. For instance, Kentucky bluegrass seed planted in shady areas should contain cultivars with resistance to powdery mildew. Other cultivars can provide resistance to many other diseases:

• leaf spot
• melting out
• stripe smut
• patch diseases

Failure to select the proper species or cultivar may result in poor or thin grass establishment and excessive maintenance needs.

When establishing a lawn with only one grass species, such as Kentucky bluegrass, perennial ryegrass, tall fescue, or fine fescue, blending cultivars within the species is recommended. A blend is a combination of two or more cultivars of the same grass species. Two to four cultivars are normally recommended. This gives the lawn greater genetic diversity which improves disease and insect resistance, and adaptations that allow the turf to thrive in differing environmental conditions. Planting a blend does not necessarily guarantee resistance to any pest but if done properly it will provide some resistance to insects, diseases, and cultural stresses while providing a turfgrass area that is uniform in appearance. Blending also helps ensure that the entire lawn will not be lost if it’s attacked by pests or subjected to abnormal cultural or environmental stresses. Blends that have been created by reputable seed companies should ensure that genetic color, texture, and pest tolerances are all rated similarly for the species you are using (NTEP n.d.) via the National Turfgrass Evaluation Program..

Variations in cultivar compatibility can result in a patchy look to a lawn despite the grasses being the same species. When choosing cultivars, discuss this with a reputable seed dealer prior to purchasing your seed. If mixtures (combinations of two or more grass species) are used, consideration should also be given to ensuring there are similarities in appearance, growth habitat, ability to compete, and the climatic adaptation of the cultivars within each species.

In most communities, local retailers or grain elevators have turfgrass seed available in bulk and there are often blend varieties or mixes of species based on the needs of the customer. If the only seed available is through prepackaged products, carefully review the seed label for information about the package's contents. By understanding the information on the label, you can choose the grass seed that best fits your needs based on the most important factors for lawn grass cultivar selection:

• cultivar(s) present
• percent germination
• date of germination test
• percentage of inert matter and weed seeds
• the ratio of the species (if mixed species)

The Federal Seed Act (USDA n.d.) mandates certain requirements of seed labeling that must be followed by all seed packaging companies. By law, all seed sold in Ohio must be labeled and include:

• The name of the species and cultivars of each seed component that exceeds five percent of the contents and its percentage by weight.
• If a seed has no cultivar name, "Variety Not Stated" must be listed.
• The following information will be on the typical grass seed label:

1. A lot number used by the company to identify the seed lot.
2. The origin of the seed. If the origin is unknown, the label should indicate the origin as "Unknown."
3. The percentage (by weight) of weed seeds, especially noxious types.
4. The kind and quantity (by weight) of noxious weed seeds.
5. The percentage (by weight) of agricultural seed found other than desired types.
6. The percentage (by weight) of inert matter or empty hulls, sterile seeds, insect parts, etc. not discarded while processing.
7. The germination percentage for all agricultural seed in excess of five percent and the percentage of hard (infertile) seeds, plus the month and year of the germination tests.
8. The name and address of the seller and the manufacturer’s code.

The best lawn will be obtained using high-quality seed containing no weed or other crop seed. Although a higher quality seed may be more expensive, the premium price is a good investment in obtaining a high-quality lawn. If lower quality alternatives are used, there is potential for increased weed issues as well as inconsistent responses to environmental stresses and pest outbreaks.

Turfgrass seed is harvested in the summer and tested in the fall and winter. This seed is usually offered for sale the following growing season. With time, the germination rates of the seeds will decline. The rate of the decline depends on the conditions under which the seed is stored. Cool, dry storage will favor seed preservation. Compensate for a slight decline in the germination percentage by slightly increasing the seeding rate. To optimize germination, it is recommended that seed no older than one year be used— refer to the seed label for the date of testing to check on this.

The four turfgrass species most commonly used in lawn establishment in Ohio are Kentucky bluegrass, perennial ryegrass, tall fescue, and fine fescue. Many of the best commercial cultivars and promising experimental selections of these species are evaluated in a program sponsored by the United States Department of Agriculture. This program, the National Turfgrass Evaluation Program (NTEP), evaluates and compares cultivars at selected sites across the United States and Canada. The cultivars are evaluated based on color, quality, leaf texture, seedling vigor, cold hardiness, summer stress tolerance, disease, insect susceptibility, and other factors. The results are compiled for each cultivar, summarized, ranked, and then published in yearly reports. Summary rankings of the top commercially available cultivars—based on quality ratings—for the four most prominent turfgrass species in Ohio are listed below.

Top Commercially Available Turfgrass Cultivars

All cultivar data listed below is derived from NTEP evaluation trials at Michigan State University and Purdue University. All cultivars listed are statistically within range according to Fisher's Least Significant Difference (LSD), which is used to compare means from multiple processes.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

References

National Turfgrass Evaluation Program (NTEP). n.d. Accessed September 1, 2021. https://ntep.org/contents2.shtml.

U.S. Department of Agriculture (USDA). n.d. "Federal Seed Act." Agricultural Marketing Service. Accessed September 9, 2021. https://www.ams.usda.gov/rules-regulations/fsa.

Revised 2021: Edward J. Nangle, Agronomist, Ohio State University Extension, CFAES Wooster Campus
Revised 2021: David S. Gardner, Agronomist, Department of Horticulture and Crop Science, Ohio State University Extension
Original author 2002: William Pound, Agronomist, Ohio State University Extension
Original author 2002: John R. Street, Agronomist, Ohio State University Extension