8 minute read
Cover Story
Why Zoysiagrass?
By Grady Miller and Ray McCauley
It is not every day that a homeowner picks a grass for their yard. With the number of variables to consider, it can be a stressful decision. From an economic perspective, it is not just the cost of a new yard, but the long-term maintenance that comes along with it. Since a specific grass usually has some unique management requirements as well as specific visual distinctions, the decision will have ramifications that can last many years.
Central North Carolina is in the transition zone: an area where the summers are too hot for cool-season grasses to thrive and the winters are too cold for the warm-season grasses to maintain winter growth and quality. But this also translates to an area that can grow about any grass with some level of success most years. The turfgrasses best suited for central North Carolina are tall fescue, tall fescue/bluegrass mixtures, zoysiagrass, centipedegrass, and bermudagrass.
In the last several years it seems that tall fescue, zoysiagrass, and bermudagrass have become the most popular grasses for moderate to high maintenance landscapes in central North Carolina. That is not to say that other grasses should not be used, but the focus of this article will concentrate on zoysiagrass.
I realize that some people will read this article with preconceptions. It is not uncommon for people to have strong opinions about their “favorite turf.” The intention of this article is not to convince readers that zoysiagrass is superior to other grasses, but to highlight its attributes and shortcomings. I also realize that tall fescue is the prevalent landscape grass in the piedmont and mountains and that centipedegrass has great popularity along NC’s coastal counties.
So the first question you may ask, “why the increased interest in zoysiagrass?” The best answer to this question relates back to climate change and the resulting weather extremes. Weather data suggests that our nighttime temperatures have been increasing, and we seem to have more frequent droughty periods. When a state or region experiences a widespread drought, people start considering their everyday practices and wondering, “are we doing what we should be doing to maximize the use of our fresh water?”
A second question one may ponder is why tall fescue, centipedegrass, and bermudagrass are also popular turfgrass choices? Comments that I often hear are that tall fescue can be easily established from seed, that centipedegrass requires very low maintenance, and that bermudagrass is the most drought tolerant turfgrass. All this is true, as each grass species has unique characteristics that make it desirable for different circumstances. While a single characteristic of a grass may result in it being favored, I do not believe a grass should be selected based on only one characteristic. The Carolina Lawns publication (available from www.turfFiles.ncsu.edu) highlights the general characteristics of NC turfgrasses.
Tall fescue is easily established from seed, one of the most economical methods of establishing turfgrasses. And when seeding is not an option, sodding tall fescue is a readily available economic option. Tall fescue is well adapted to this climatic region, and several cultivars have a long history of use. Forage type tall fescue cultivars have been available for a low price for many years (Kentucky 31 was officially released in 1942). Familiarity encourages use, and use over a long period results in a tradition. It is not uncommon to hear NC natives say, “we have always had tall fescue.” However, tall fescue will require more water than zoysiagrass or bermudagrass to keep it healthy. In some years, gray leaf spot and/or brown patch can decimate tall fescue. Control of these two diseases can be very challenging, and re-establishment is often the only option. Thus, the annual renovation/overseeding cycle continues.
The annual NC sod grower’s survey illustrates that centipedegrass has been the cheapest sod in the NC market for the last nine years. It is very well adapted to eastern NC’s climate and soil conditions. Although it can be established from seed it is more commonly established from sod. It also has been labeled as “the lazy man’s grass.” That is largely due to its preference for lower fertility, acidic soils and generally requiring less mowing than other turfgrasses. However, centipedegrass has a distinct yellowish-green genetic color, which some may find objectionable. Centipedegrass is susceptible to large patch disease, over-management (especially excessive nitrogen fertilization), and cold stress. Centipedegrass has a limited number of labeled pre- and post-emergence herbicides that be safely applied to it.
Bermudagrass has consistently been the second cheapest sod in NC during the last nine years. There are also many good cultivars that can be established from seed, although the best ones are hybrids that will require vegetative establishment. Bermudagrass does well in full sun conditions, so new neighborhoods and commercial developments without mature trees have been a popular location for planting. Unfortunately, as newly planted trees mature, they may prove to be too shady for long-term sustainability of bermudagrass. Also, bermudagrass has the highest propensity to aggressively spread into flower and shrub beds.
So, why pick zoysiagrass considering it is often one of the most expensive sods sold in NC? It is because zoysiagrass often tends to be among the top performing turfgrasses in most characteristics with no significant negative traits. It has good shade tolerance for a warm-season turfgrass, which is a big plus in the landscape. It handles full sun and has good drought tolerance, is relatively slow growing, and has very high density, which is a great deterrent to weeds. It is available in multiple leaf widths (aka textures). Diseases can sometimes be an issue but generally do not cause widespread damage when they occur. Rarely are insects an issue with zoysiagrass. There are also cultivars that can be seeded. But much like centipedegrass, the success of establishment from seed is low.
With adequate moisture zoysiagrass should be green from spring through early fall. As a warm-season turfgrass, it will usually turn a tawnybrown color by Thanksgiving. Some people just cannot accept the brown color, even though I view it as the arrival of fall similar to the dropping of leaves from deciduous trees. Also, there is little-to-no need for mowing and irrigation when zoysiagrass is in a semi-dormant to dormant condition. In a mild winter, zoysiagrass will often retain some green color, especially if the lawn is surrounded by some tree cover.
Zoysiagrass generally requires minimal fertilizer inputs. Two to three pounds of nitrogen per thousand square feet each year is generally adequate to keep zoysiagrass healthy and attractive. It will respond to additional fertilizer, but the added quantities may increase the need for thatch management and may increase the need for disease control. Since fertilizer applications should be scheduled during times of active growth, zoysiagrass should be fertilized in late spring and summer.
Large patch disease can sometimes be an issue with zoysiagrass, but damage is generally cosmetic. Spring dead spot can occur in zoysiagrass, but is much more likely to occur in bermudagrass. Zoysiagrass does not do as well as some other turfgrasses when we have cool, wet springs. Natural weed control seems to favor zoysiagrass compared to the other turfgrasses. A dense stand of zoysiagrass is a very good deterrent to weeds. Since crabgrass—our most consistent problem weed—emerges in the spring, a dense, well-maintained zoysiagrass lawn is well equipped to prevent its emergence. What weeds zoysiagrass cannot handle, a preemergence herbicide can easily augment zoysiagrass’ natural abilities. Zoysiagrass is not finicky about post-emergence herbicides compared to centipedegrass. Because landscapes often contain flower and shrub beds in addition to turf, the subject of invasiveness has to be mentioned. With stolons creeping on top of the ground and rhizomes sneaking up from the bottom, zoysiagrass will provide a constant battle to keep it out of the beds. Some type of barrier, installed at least eight inches below the ground and allowed to protrude a couple of inches above the ground will be necessary to hold back zoysiagrass.
As mentioned before, zoysiagrass cultivars have a great deal of diversity in textures. The zoysiagrasses are normally divided into two groups: coarse-textured and fine-textured cultivars. The coarse-textured cultivars available in NC include Compadre, Crown, El Toro, Empire, Jamur, Meyer, Palisades, and Zenith. The finetextured cultivars include Cavalier, Chisholm, Emerald, Icon, Innovation, Lobo, Prizm, Royal, Zeon, and Zorro. Some of these cultivars are more available than others or must be sourced from nearby states. Seed is available for Compadre (formerly called Companion) and Zenith, but seed quantities are often limited and establishment can be slow.
Given the right situation, several of our turfgrasses can produce a high quality lawn. But turfgrasses have several characteristic differences that should be considered before selecting the best one for your landscape. These differences may be deal breakers or just require you to make some simple allowances. You will have to decide which characteristics are important in your situation. Because of a complement of characteristics that are available in zoysiagrasses, one should ask, “why not zoysiagrass?” when making a selection for their next lawn grass.
