David M. Kopec, Extension Turfgrass Specialist
Zoysiagrass is composed of three species which are used for turf purposes. These include Japanese lawn grass (Zoysia japonica), manilagrass (Zoysia matrella) and mascarengrass (Zoysia tenufolia).
For lawn purposes, Zoysia japonica is the typical grass used. Z. japonica is the type of zoysia seen in the Sunday papers as the "amazing amazon" or "amazoy" grass. Around this time of year a lot of homeowners have extensive questions about zoysiagrass and are excited by the Sunday paper adds. Here are the answers to the questions you will receive about zoysiagrass.
Q. Does zoysiagrass use less water than bermuda?
A. For all intents and purposes, probably not. The difference in water use is not statistically meaningful and homeowners would not be able to apply minute differences of water with a lawn sprinkler system.
Q. Is zoysia easy to establish?
A. No, it is a slow grower compared to bermudagrass, either from seed or plugs. It is even slower than buffalograss. Since it is slower to grow, a zoysia lawn must be established in the first third of the summertime.
Q. How do I establish a lawn of Zoysia japonica?
A. Either from seed, sod, or plugs. Seed can have a high rate of dormancy (50-60%), but ask for stratified treated seed which will have 75-85% germination. The stratified seed is treated with potassium nitrate and refrigerated for a short time to increase seed germination. Plugs purchased from the "Sunday newspaper add" will be mixed genotypes of Z. japonica.
Q. How much seed should I plant and how?
A. Seed should be planted in a prepared soil bed which is free of bermuda. Bermuda should be eradicated with Round-up first. Seeding should take place at 3-4 lbs. per thousand square feet. Gently rake in the seed to a 1/4" depth and tamp or roll the seedbed. Water lightly several times a day until the seedlings emerge.
Q. How about sodding or plugs?
A. Sodding and/or plugging is essentially the same as would be done for bermuda. The turf must not be allowed to dry out during the rooting process. The variety 'El-Toro' is a popular zoysia which is available as sod. You can make your own plugs of it if you wish.
Q. How much fertilizer and mowing does it take?
A. Once established in the second year, you can apply about 1/2 as much fertilizer as you would for bermuda. The first summer it needs about as much as bermuda would to assist in establishment. Z. japonica has two regimes. For a short lawn, mow the grass at 1.5 inches with a reel-type mower when it reaches 2.0 inches. For a higher cut lawn, mow zoysiagrass at 2.5 inches when it reaches 3.0 inches with a rotary-type mower. When zoysia is scalped, it is slow to recover.
Q. Can I overseed zoysia?
A. Zoysiagrass holds its color later in the fall then bermudagrass and greens up about the same time (a little slower). Zoysia does not like the disturbance which goes with overseeding. So, don't overseed it.
Q. Can I grow zoysia in the shade?
A. Yes, if the shade is light to moderate. It will not persist under heavy or total shade.
Q. Does it take cold winters better than bermuda?
A. Probably yes. Z. japonica lawns will stay dormant for long winters, but should have at least a full four months of non-dormant growth to persist.
Q. Where is it adapted to in Arizona?
A. Anywhere bermudagrass is. I would imagine it could "survive" short summers in Payson and Prescott and up in Winslow. However, that's really pushing it.
Q. Does zoysia take traffic like bermuda?
A. In the heat of the summer for short periods only. The leaves are tough and rigid. Once it's worn out, it is much slower to grow back than bermuda after receiving wear.
Q. Is it a maintenance free lawn?
A. No, it is a low maintenance lawn. After 2-3 years, the tough stolons can form quite a thatch. Dethatching must be done in the late spring, so there are enough hot days left for the zoysia to grow back completely. Zoysia does exhibit leaf yellowing from iron chlorosis in our high pH soils. Applications of iron are most likely needed at some point.
Q. Where can I get Zoysia japonica?
A. Arizona sod growers no longer grow zoysia sod due to low demand. Seeded zoysia's include "common zoysia" and "Meyer."
Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director, Cooperative Extension, College of Agriculture & Life Sciences, The University of Arizona. The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.