Turf Tips
Zoysiagrasses: An Update
By Tom Samples and John Sorochan, University of Tennessee, Department of Plant Sciences
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oysiagrass, one of the earli- est grass species to be used as turf, is native to Australia, China, Japan, Korea, New Zealand and the Philippines where the weather varies greatly depending on season. This relatively slow-growing, sod- forming and warm-season species forms a durable, uniform turf in full sun and light, open shade. Many
zoysiagrass varieties produce no viable seeds and must be established from sod, plugs or sprigs. Depending on the planting date, sprigging rate, and plug diameter and spacing, the vegetatively propagated varieties often require more than a year to totally cover the soil surface. Leaves and stems developing from nodes on stolons and rhizomes usually grow upright at an angle of about 90 degrees, a trait contributing to very good to excellent stand density. Zoysiagrass leaves are often stiff and stems are very tough due to high levels of lignin and hemicellulose. These attributes result in excellent wear tolerance. The slow rate of growth of lateral stems compared to that of bermudagrass and St. Augustinegrass causes zoysiagrass turfs to take longer to recover from damage from traffic, disease or insect activity. Generally, zoysiagrasses have very good drought, heat and salinity tolerance. The nitrogen (N) requirement of the species is usually lower than that of bermudagrass. In TN, an annual N rate of no more than 2 lbs. of N per 1,000 sq. ft. per yr. is most often recommended in residential turfs maintained at a cutting height of 1½ inches or higher. Plants often do produce substantial amounts of thatch, and intensely managed and highly fertile zoysiagrass turfs may require dethatching every two or three years.
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Insect pests of zoysiagrass include white grubs (larvae of several species of Scarab beetles), fall armyworm (Spodoptera frugiperda) and hunting billbug (Sphenophorus venatus vestitus). The disease large patch (Rhizoctonia solani), commonly referred to as Zoysia patch may also be problematic. Bermudagrass (Cynodon spp.) is a common weed problem in zoysiagrass turfs. Perennial weeds with fleshy, subsurface and energy-rich bulbs such as wild garlic (Allium vineale), yellow nutsedge (Cyperus esculentus) and green kyllinga (Kyllinga brevifolia) can also compete with zoysiagrass for water, nutrients, light and space and may periodically require herbicide treatment. An appropriate preemergence herbicide can be applied in late summer or early fall to control winter annual weeds such as annual bluegrass (Poa annua), common chickweed (Stelaria media), purple deadnettle (Lamium purpureum) and henbit (Lamium amplexicaule). Similarly, the emergence of seedlings of many summer annual and perennial weedy grasses and broadleaf weeds can be prevented by applying an appropriate preemergence herbicide in late winter or early spring. In addition to insect and disease resistance, the growth rate, low-temperature hardiness, leaf width, color and shade tolerance also vary among species and varieties.
Species Zoysiagrass, named in honor of the 18th century Australian botanist Karl von Zois, was introduced into the U. S. from East Asia and the Pacific Islands. It has been previously reported that, in the mid-1890’s, Z. japonica, sometimes called Japanese or Korean lawn grass, was
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March/April 2019
introduced into the U. S. from the Manchurian Province of China. Zoysia matrella was believed to have been introduced into the U.S. from the Philippine Islands in 1912 by the United States Department of Agriculture (USDA) botanist, C. V. Piper. As a result, this species is occasionally referred to as Manilagrass. Recent research regarding the history of zoysiagrass suggests that Z. matrella may actually have been introduced into the U. S. from Japan in 1892, and that Z. japonica was introduced into the U.S. from Korea in 1894. A third species, Korean velvet grass or Mascarene grass, was most likely introduced into the U. S. from the Mascarene Islands (which are located in the Indian Ocean east of Madagascar) or from a plant collection (listed as plant introduction 9299) of USDA explorer David Fairchild in 1902 from Yokohama, Japan. Originally referred to as Z. tenuifolia, this very fine textured species is now recognized as Z. pacifica. Rankings of lowtemperature hardiness, leaf width and rate of growth by species are: Z. japonica > Z. matrella > Z. pacifica.
Varieties Vegetative, Clonal Types. Improved, vegetatively established varieties marketed in Tennessee include ‘Cavalier’, ‘Diamond’, ‘El Toro’, ‘Geo’, ‘Meyer’, ‘Palisades’, ‘Royal’, ‘Zeon’ and ‘Zorro’. El Toro, Meyer and Palisades are medium-coarse, low-temperature-hardy varieties. Meyer, released in 1951, is one of the oldest varieties in the marketplace and remains the most widely maintained zoysiagrass in the state. El Toro, released in 1986, resembles Meyer. However, El Toro is more shade
