Selecting Turfgrasses for Missouri
Turfgrass selection is the most important cultural practice in turfgrass management and can have a major impact on turf quality. A quality lawn containing the recommended mixtures of species or blends of turfgrass varieties can be a difficult process and decision. Selecting turfgrass species depends on how you manage your lawn and what you expect of your lawn. Grasses differ in adaptation, cultural requirements and performance. Managing a lawn requires decisions on frequency of mowing, a fertilizer program, and your choice to water your lawn or not. Selections can also be based on existing environmental conditions (level of moisture, degree of sunlight, topography) and the purpose for which the grass will be used. The answers to these questions will help you decide which type of lawn you wish to establish.
Blends (3 to 4 varieties in equal portions) of Kentucky bluegrasses look rich with dark blue-green colors and have good resistance to brown patch disease, although they do require more inputs of fertilizer and water to maintain that rich cover through the summer months. They are also more susceptible to dollar spot, leaf spot, rust, and summer patch diseases. Selecting bluegrass varieties that offer resistance to some of these diseases is a practical first step in lawn establishment. Bluegrasses develop tillers and small rhizomes, which enable bluegrasses to recover from thinning or other problems. They grow well in full sun to partial shade and have good wear tolerance and recoverability.
Blends (three to four varieties in equal portions) of turf-type tall fescues can give deep emerald green appearances with a slightly coarser texture than the bluegrasses. They tend to be a deeper rooting plant, therefore requiring less water than a bluegrass lawn. They are not as susceptible to dollar spot and summer patch, but generally will require some fungicides for the control of brown patch disease. Several varieties of turf-type tall fescues offer superior resistance to brown patch and therefore will improve turf quality. Tall fescues will tiller to help with recovery, but tend to be clumpy with severe thinning. They also grow well in full sun to partial shade.
Mixtures, such as turf-type tall fescues (in a blend) with Kentucky bluegrasses (90 percent fescue, 10 percent bluegrass), combine the advantages or strengths of each species to mask the weaknesses of the other. Any grass seed mixture with perennial ryegrass should not exceed 20 percent perennial ryegrass, as it is susceptible to most of the diseases list above. Ryegrass is not very heat or drought tolerant and does not recover from thinning of cover. Unfortunately, many seed mixtures and blends available to homeowners at local garden centers contain large amounts of ryegrass (both annual and perennial) and fine-leaf fescues (creeping red fescues, hard fescues, etc.). Fine-leaf fescues have little tolerance for direct sunlight.
So which varieties do you select once you decide on a blend or mixture to plant? Various resources provide recommendations for turfgrass varieties for Missouri. Garden centers, MU Extension publications, turfgrass specialists, and other lawn care experts are good sources for information about turfgrass selections. Thedifficulty for most individuals is to find the varieties suggested. We will discuss several options.
Grass seed bags have a seed label printed or pasted on the bag. Several pieces of information on the label should be considered before seed is purchased. A seed tag will list the species (Kentucky bluegrass, tall fescue, perennial ryegrass, etc.), variety name (Kenblue, Abbey, Plantation, Crossfire II, Shining Star, etc.), purity (should be greater than 90 percent), germination (should be greater than 80 percent), weed seed content (percent) and noxious weed seed content (percent) and testing date (should be 12 months or less). The species and variety name of the seed will tell you exactly what you’re buying. As long as the purity and germination are acceptable, the next most important information to consider is the weed listings. The best products list 0 percent for weeds and noxious weeds. Any product containing weed seed will list the type of weed seed contaminating the turfgrass seed. Avoid any seed product containing noxious weeds.
Specific varieties, blends and mixtures available
Number of seed products being sold over-the-counter can be overwhelming to homeowners. However, by looking at the seed tags on products, several can be eliminated immediately. These include products that contain large percentages of ryegrasses. Many of these seed products are packaged for national sales and while they are excellent products for many areas of the country, they are not the best for the type of climate we deal with in Missouri. Concentrate more on the products that are tall fescue and Kentucky bluegrass blends or mixtures of tall fescue and Kentucky bluegrass. By doing this the selection choices becomes more narrow and simplified.
Individual varieties (from different venders) of tall fescues can be found locally to create your own blends. Measure equal portions of each variety used and combine thoroughly in a large clean bucket or trashcan. You have now created your own tall fescue blend. Some of the tall fescue varieties available locally include:
Table 1. Turf-type Tall Fescue
Several pre-packaged blends of tall fescue can also be found. These will generally have some of the better varieties acceptable for Missouri, but it still does not hurt to check those seed tags. These include:
Table 2. Turf-type Tall Fescue
The next selections are Kentucky bluegrasses; some may have only a single variety, others are blends. One can always check the seed tag to know what you are purchasing. These products usually offer some of the better varieties acceptable for Missouri as well. They include:
Table 3. Kentucky Bluegrasses
The mixture we discussed with tall fescue and Kentucky bluegrass has several nice combinations available over-the-counter. Many venders also feel the 90/10 combination of tall fescue and Kentucky bluegrass is an excellent choice. Of all mixtures, this is possibly the best for Missouri. Some of these products include:
Table 4. Tall Fescue/Bluegrass
Heat and drought is always a major concern during Missouri summers for cool-season grasses. A new heat tolerant bluegrass is now available to homeowners in a packaged mix with tall fescue. Scott’s “Pure Premium Heat-Tolerant Blue” includes one of these new heat tolerant bluegrasses called, “Thermal Blue.” Heat tolerant bluegrasses are genetic crosses between Texas Bluegrasses and Kentucky bluegrasses that show excellent heat and drought tolerance. They are recommended in areas where tall fescue and Kentucky bluegrass are presently recommended. This product should be available where other Scott’s products are sold.
Shade’s effect on turfgrasses is a very common question for home lawns. Many turfgrasses are tolerant of moderate shade, however no turfgrass is tolerant of total shade throughout the day. The following table does list some mixtures available for moderate shade. Just keep in mind that moderate shade should still allow at least three hours of direct sunlight daily.
Table 5. Shade Mixtures (Tall fescues, creeping red fescues, Kentucky bluegrass and perennial ryegrass)
The above information is intended to make the selection process for turfgrass seed less troublesome and giving you more confidence in your choices. Be sure to always check with your local garden centers first for availability of these products, since all stores do not carry complete product lines.
When to establish
Selecting the right time of the year to seed cool-season grasses is the most important factor in successful lawn establishment. The best time to seed cool-season grasses is between Aug. 25 and Oct. 1. Lawns seeded within a week of Labor Day are more likely to fill in completely by winter and produce a thicker appearance the following spring than lawns seeded in October.
Seeding in late summer is preferred because temperatures are warm enough to promote rapid germination if there is rain or irrigation. The cooler temperatures and shorter days of the approaching fall are ideal for further growth and development of seedling grasses. Summer annual weeds are usually not a problem as the frost of early fall puts an end to their season and eliminates any competition.