Zoysia grass turning brown

Zoysia Diseases – Tips For Dealing With Zoysia Grass Problems

Image by Ryan Q

Zoysia is an easy-care, warm-season grass that is highly versatile and drought tolerant, making it popular for many lawns. However, zoysia grass problems do pop up on occasion – most often from zoysia diseases like brown patch.

Common Zoysia Grass Problems

Although relatively free from most pests and diseases, zoysia grass isn’t without its faults. One of the most common zoysia grass problems is the buildup of thatch, which is caused from undecomposed organic matter. This buildup forms just above the soil line.

While raking can sometimes alleviate the problem, regular mowing helps to prevent thatch from accumulating throughout the lawn. It also helps to limit the amount of fertilizer used on zoysia grass.

If you find sections of zoysia dying, this could be attributed to grub worms. Read detailed information on grub worm control here.

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Zoysia Diseases

Brown patch, leaf spot, and rust are also common zoysia grass problems.

Brown Patch

Brown patch is probably the most prevalent zoysia grass disease, with patches of zoysia dying off. These dead patches of grass start small but can quickly spread in warm conditions. You can typically identify this zoysia disease by its distinct brown ring that encircles a green center.

Although fungal spores of brown patch cannot be fully eliminated, keeping zoysia healthy will make it less susceptible to the disease. Fertilize only when needed and water in the morning after all dew has dried. For further control, there are fungicides available.

Leaf Spot

Leaf spot is another zoysia disease that occurs during warm days and cool nights. It is usually caused from overly dry conditions and lack of proper fertilizer. Leaf spot develops small lesions on grass blades with distinct patterns.

Close inspection of spotty areas of zoysia dying will oftentimes be necessary to determine its actual presence. Applying fertilizer and watering grass deeply at least once weekly should help alleviate this problem.

Rust

Rust in grass often develops during cool, moist conditions. This zoysia disease presents itself as an orange, powdery-like substance on zoysia grass. Other than using appropriate fungicides targeted toward its treatment, it may be necessary to retrieve grass clippings after or during mowing and properly disposing of them to prevent further spreading of this grass rust.

While zoysia grass diseases are few, it never hurts to check into the most common zoysia grass problems whenever you notice zoysia dying in the lawn.

My Zoysiagrass Lawn was Beautiful – Now What Should I Do?

Brad S. Fresenburg
University of Missouri
(573) 884-8785

Lee Miller
University of Missouri
(573) 882-5623

Published: May 30, 2013

Homeowners who have zoysiagrass lawns have greatly appreciated the density and color of these lawns for their competition against weeds and that carpet-like feel. Zoysiagrass is the warm-season grass of choice for lawns and it has proven to be a good one for the hot and humid summers of Missouri. Until recently there were no major complaints, other than the usual invasiveness of this grass species.

Zoysiagrass lawns have not been looking well over the past couple of years. Most complaints have been received in the St. Louis area; however we are getting calls from Jefferson City and many other outlying communities. In a 2012 article, three possible scenarios were discussed for the demise of zoysiagrass lawns. These include: Large Patch disease, Hunting Billbug, and Chinch Bug.

Large patch is the number one biotic problem that affects zoysiagrass on an annual basis. It is indiscriminate in its occurrence, and will damage lawns or golf courses with similar intensity. The disease is caused by the fungal pathogen, Rhizoctonia solani, and is a close relative to the identically named pathogen that causes brown patch on tall fescue. Large patch symptoms can occur in the fall but are most severe now in the spring, when zoysiagrass is slow growing due to the cool temperatures we have been experiencing.

Large Patch in Zoysiagrass. Note: Brilliant orange Firing on patch parimeter.

In addition, large patch is particularly severe and spreads quickly in saturated or flooded soils, which have been spurred by our numerous rainfall events. In active outbreaks, leaves on the outer margins of patches will “fire” and turn a brilliant orange color that is most vivid in the morning or after a rain event. As the name implies, large patch symptoms can be quite grand in nature, with patches ranging from 6 inches to many, many feet in diameter. Some extreme outbreaks can even be observed with satellite imagery!

Large patch is not easy to control, and researchers are still learning important aspects of the disease cycle in order to develop more effective management practices. It is critical that timing of fertilization and other cultural practices is done in accordance with when zoysiagrass is actively growing. Nitrogen fertilization in the fall or spring when zoysia growth is slow may tip the scales squarely in favor of the large patch pathogen and result in severe outbreaks. Similarly, aerification and thatch removal practices should be limited to the hot summer months. So, in other words, don’t do anything to zoysia unless you are actively sweating while doing it. As noted above, the pathogen also depends on moisture to infect, so over-irrigation and poor drainage will also result in more severe large patch outbreaks.

Satellite imagery of a zoysiagrass lawn infected with Large Patch.

Chemical control of large patch should be limited to areas that have a history of the disease. If fungicide control is necessary, the application must be timed preventively when infection is taking place not when symptoms occur. Actual infection of the fungal pathogen occurs in early fall when the fungus dives down to the base of the plant inside the leaf sheath. Therefore, fungicide applications should be made in the fall. Recent research suggests earlier may be better in early to mid-September when soil temperatures first dip to below 70°F. To minimize fungicide use, it is possible to map out the diseased areas on lawns now, and specifically apply fungicide to these areas this fall. Fungicide applications made to lawns in spring will protect your healthy grass from large patch expansion, but will not magically cure zoysia that has already been infected. Fungicides marketed for homeowner application may not be as effective as those marketed to commercial lawn care operators. Additionally, specialized spray equipment used by commercial lawn care operators may make these fungicide applications more effective.

Chinch bug and hunting billbug outbreaks were also noted on several lawns in the St. Louis and Jefferson City area in the past two years.

Chinch bugs (Blissus spp.) are the most damaging insect pest in zoysiagrass. Unlike large patch, chinch bug damage occurs in the hot, dry summer months and most closely resembles drought damage. Affected areas are solid, not patchy, and will usually start on one side of the lawn and progress throughout as the chinch bug population builds and moves. Damage is most severe along lawn boundaries, particularly along concrete driveways and sidewalks. The easiest method to detect chinch bug damage is to pull up damaged zoysia along these boundaries and look for the scattering fast, small 3/16-inch black bugs. If chinch bugs are occurring, there is no recourse but the use of a curative insecticide to eliminate the problem. Because occurrence is sporadic from year to year, preventive insecticide applications targeted for chinch bugs are not recommended in this area.

Hunting billbugs (Sphenophorus venatus vestitus) have also been found sporadically in Missouri over the last two years. Unlike chinch bugs, hunting billbugs are more anonymous and elusive. Because of this little is known of hunting billbug biology. Adults are reddish brown-black, 1/2-inch long, have a curved snout, and are most active during the night and early morning hours. Billbugs are thought to overwinter as adults, and lay eggs in grass stems/leaf sheaths in mid-late spring. Billbug larvae, which unlike annual white grubs are legless, hatch and feed by boring into lower leaf stems. Larvae become larger and also feed on stolons, which are left characteristically hollowed out in early summer. At this point, zoysia will easily pull away from the soil, and symptoms will occur as yellow areas that eventually brown and die out, resembling drought damage. Monitoring both adult and larval hunting billbug activity is difficult. The most effective method for detection of adult activity (which should be occurring soon) is creating several pitfall traps in the lawn by digging a few holes and placing plastic cups level to the soil surface. Adults will fall into the cup overnight and can be counted over a few days period. Early larval stages are small and difficult to detect, but larger larvae in July can be observed by pulling zoysia away from the soil. In areas where hunting billbug damage has been identified, a preventive long lasting insecticide application should be applied in late May – early June (same time frame for annual white grubs) to target both adults and larvae.

Sticking with Zoysia

Many homeowners are asking, “What should I do?”, “Should I replant zoysiagrass or should I plant something else?” There are many advantages to a zoysiagrass lawn compared to a cool-season turfgrass, which include the capability of mowing zoysiagrass shorter, and an improved tolerance to heat, drought and diseases. It is not, however, nor is any turfgrass species, maintenance free. For those who truly love their zoysiagrass lawns, replanting zoysia in early June is the best timing for re-establishing these lawns. However, if temperatures remain cool and Large Patch remains active; hold off on re-establishing zoysia until Large Patch symptoms disappear. Zoysiagrass recovery can be accomplished by seeding (‘Zenith’ or ‘Compadre’ @ 1 to 2 lbs/1,000 sqft), plugging (2 inch plugs planted on 1-foot centers), sprigging (10 to 12 bushels/1,000 sqft) or sodding.

By knowing what pests have caused the recent demise of zoysiagrass, homeowners can follow the previously outlined recommendations for control of these pests. To diagnose causes of declining zoysiagrass, homeowners can utilize the turf diagnostic service at the University of Missouri (http://turfpath.missouri.edu/turfdiagnostics), or call their local extension office.

Conversion to Cool-Season

Others may choose to do something else with their lawns. Right now the most common question is how to convert these zoysia lawns to a cool-season grass like tall fescue or tall fescue/Ky. bluegrass.

If this is the route you wish to take, then your conversion to a cool-season lawn can begin now until mid-July. The first step is to spray Roundup herbicide to remove the zoysia and any weedy vegetation that may be present due to thinning of the zoysia. Following the initial Roundup application, continue to monitor any regrowth every 10 to 14 days throughout the remainder of the summer. Spot spray with Roundup to kill any re-sprouting of zoysiagrass or weeds. Your lawn will be dead and ugly throughout the summer, but this is the necessary evil to convert a warm-season lawn to a cool-season lawn.

You need to be aware of the fact that warm-season grasses such as zoysiagrass spread by rhizomes (root extension below the soil surface that will produce daughter plants) and stolons (surface runners that help this grass to spread and produce daughter plants). All nodes on these rhizomes and stolons need to be killed by Roundup in order to make a complete conversion. Conversion from warm-season grasses to cool-season grasses is the most difficult conversion to make and no guarantees can be made. There is always the possibility that some zoysia can come back and contaminate your new cool-season lawn. This contamination can be from re-sprouting of zoysia within your lawn area or encroachment from outside your lawn area (from a neighbor’s lawn).

Your goal is to plan on seeding fescue or fescue/bluegrass in the first week of September. Therefore your final Roundup application should be made 7 days prior to seeding. Roundup has a 7-day reseeding interval specified on the label.

Prior to seeding, conduct a regular soil test to determine if any nutrient deficiencies are present as well as determining the soil pH (click to see MU pub 6954 for more information on Soil Testing your Lawn). Make plans to add any fertilizer and/or lime based on the soil test at time of seeding. Also prior to seeding, select a good tall fescue blend or mixture of tall fescue & Kentucky bluegrass (90% tall fescue with 10% Ky. Bluegrass). Several seed products are available from various venders that should work well for Missouri. See selections below.

Turf-type Tall Fescue Blends
Vendor
Revolution Ace Hardware, Williams Lawn Seed
Winning Colors Lebanon Turf, Hummert International, MFA
Independence Hummert International
All-Pro MFA
George’s “Magic Mix” Fescue Blend R. G. Robinson
Pennington Ultimate Tall Fescue Blend Lowe’s, Wal-mart
The Rebels Blend Lowe’s, Wal-mart
Tri-Star Fescue Blend Orscheln’s Farm & Home
Lesco Fescue Blend Home Depot
Scott’s Classic Tall Fescue Blend Lowe’s, Home Depot
Tall Fescue/Bluegrass Mixtures
Vendor
Fescue Blue Mix Hummert International
Revolution Plus Williams Lawn Seed
Winning Colors Plus Lebanon Turf
Tournament Quality Ultra Premium Fescue Plus Lawn Mixture Lowe’s
Tri-Star Low Water Lawn Seed Orscheln’s Farm & Home
Pennington Fescue/Bluegrass Lawn Seed Mixture Lowe’s, Wal-mart
Master Turf Ultimate Blue Lawn Seed Mixture Wal-Mart

On the day of seeding, assuming that all zoysiagrass and other vegetation remained dead; we can begin by scalping down and bagging all dead leaf tissue. Set your mower as close as possible (lowest setting without stalling mower or cutting soil) and remove dead tissue with a bagger or by raking up material. This should make soil visible and ready for power raking or tillage. Tilling with a garden tiller may create clumps and bring excess plant material to the surface that may require additional raking and removal. Power raking (in 2 or 3 directions) will create a seedbed, but may cause some need for additional raking as well. The surface should be a fine powdery seedbed with little or no trash (dead plant material) remaining.

Power rakes should be set to slice through the top ½ inch of soil to create a seedbed.

Seed, fertilizer and lime may be added at this time. It is always recommended to apply these products at half rates in two directions to improve distribution. Seeding rates for tall fescue blends and fescue/bluegrass mixtures should be around 7 to 9 lbs/1,000 sqft. Fertilizer and lime rates are based on the soil test. Starter fertilizers are often recommended at time of seeding and the amounts can be figured into the recommendations from the soil test for P (phosphorus) and K (potassium). Starter fertilizers can be applied with the seed on the day of seeding or can be applied 7 to 10 days after seeding, when seedling grasses have emerged. This provides seedling grasses with nutrients when they need it the most. Starter fertilizers only need an application rate of 0.5 lb nitrogen/1,000 sqft.

After spreading seed, fertilizer and/ or lime, lightly rake in all three with a garden or leaf rake. A small roller can also be used after raking to improve seed/soil contact and germination. Following this, straw can be spread for mulch at a rate of 1 bale of straw/1,000 sqft (about 70 to 80% coverage). You can also use other commercial seed mulches, making applications according to their labels.

Same lawn as in satellite imagery.

When seed and straw are in place, the only task remaining is proper watering to ensure good germination. Light, frequent watering is the key to proper irrigation for seed establishment. Keep in mind that fescues require 7 to 10 days for seed germination, therefore light, frequent watering during this time is critical. Moist soil looks darker in color than a dry soil. Maintain moist looking conditions during this time; avoid puddles and runoff during seed establishment. Once seedlings begin to emerge, you can begin to back off on watering as seedling roots grow deeper into the soil.

Three weeks after seeding. Note: mowing begins.

Six weeks after seeding you can really begin to enjoy your new lawn.

In three weeks, your lawn should be tall enough to mow. Begin mowing just as soon as your lawn is at a proper mowing height. Begin with a 3-inch mowing height for new fescue lawns. This should force grass plants to tiller (produce additional shoots) and increase density. In time, mowing heights can be increased to 3.5 to 4 inches high by the following spring. Mowing taller produces a shade effect to reduce weed seed germination as well as creating a plant with a deeper root system to improve heat and drought tolerance during summer months.

After three weeks, a second fertilizer application can be made with a standard 3-1-2 ratio fertilizer at a rate of 0.5 to 0.75 lbs of nitrogen/1,000 sqft. Also note, straw does not need to be raked up in this process. It will eventually be mulched by the mower and/or decompose.

After six weeks, a final fertilizer application can be made with a standard 3-1-2 ratio fertilizer at a rate of 0.75 to 1.0 lbs of nitrogen/1,000 sqft. From this point in time on, continue mowing at a regular interval to avoid excess clippings until winter sets in. Always mow tall and let the clippings fall to return nutrients back to the soil.

Conversion from a warm-season lawn, like zoysiagrass, to a cool-season lawn like tall fescue is difficult. That is why the elimination of zoysia with Roundup throughout the summer is critical. While your lawn will look dead and brown for most of a summer, the rewards of a green lawn in the fall may well be worth your time and effort.

Zoysiagrass lawns can withstand diseases if they are properly cared for. This includes fertilizing properly, mowing at the right height and watering when needed. It is better to control diseases by proper maintenance than by using fungicides.

There are three common diseases of zoysiagrass lawns:

BROWN PATCH is most prevalent on zoysiagrass which has been heavily fertilized when night temperatures are above 68 degrees and day temperatures are above 80 degrees. Dead patches of grass may start small but can grow and join together to make patches more than 3 feet apart. Sometimes, there will be a ring of brown, dead grass surrounding a patch of green grass. To control brown patch, fertilize zoysia moderately in summer and if you irrigate, do it in very early morning. There are lawn fungicides available to control brown patch. Read the label carefully and use the rate and timing that is indicated.

DOLLAR SPOT occurs when nights are cool and days are warm in the spring and again in the fall. The spots of dead grass are about the size of your hand. They are very noticeable on closely mowed lawns. Look for a lesion on the grass blade, particularly on the edge of the grass blade. Sometimes these areas go all the way across the blade, causing the tip to die and to take on a straw color. The pattern and color of lesion development on the foliage is a good means of distinguishing dollar spot from brown patch.

Dollar spot is associated with a lack of fertilizer and drought conditions. To control it, apply a moderate amount of fertilizer and irrigate deeply only one time per week. There are lawn fungicides available to control dollar spot patch. Read the label carefully and use the rate and timing that is indicated.

RUST is usually noticed when a cloud of orange powder shoots out from a lawnmower. The disease depends on the cool, moist conditions of late fall. It is likely to be more severe in shady areas. Try to control it first by applying a moderate amount of fertilizer. Use a low nitrogen fertilizer in fall. Five pounds of 5-10-15 per 1000 square feet of lawn is recommended. Mow every 4-5 days and try to catch the clippings if possible. There are lawn fungicides available to control rust. Read the label carefully and use the rate and timing that is indicated.

You have brown patches of dead grass in your lawn. Is it the common lawn disease ‘brown patch’ or is it something else? The answer is important: if it is brown patch you probably need to spray with a fungicide. If is not, you’ll waste your money buying expensive fungicides.

DISEASE vs ENVIRONMENT While brown patch does cause patches of dead grass, other things can cause the same symptoms. If the area is poorly drained and water stands on a spot for more than 24 hours, the grass roots will rot, causing a dead patch. If you have a sodded lawn less than one year old, it is possible the soil underneath the sod was never plowed to relieve compaction. Where the sod has rooted poorly, brown patches will develop as dry weather sets in. If one part of the lawn was once used as a baseball home plate or a soccer goalie area, the earth beneath is almost as hard as concrete. It’s easy to see why green grass would turn brown there.

BROWN PATCH SYMPTOMS If you eliminate environmental causes of the brown patch, what are the true symptoms of the disease? True brown patch spots are small to begin with but in warm weather they can enlarge rapidly. Seen from above, the patch will look like a doughnut – a ring of tan grass having a patch of green grass in the center. Individual grass blades will be brown down to the crown – where the blade emerges from the ground – but the crown will be green. Early in the morning during hot, damp weather you might see a white fungal web at the edge of the dead grass patch.

KEEP GRASS HEALTHY Remember that the fungus that causes brown patch is constantly present. It can not be eliminated. Your grass gets sick because it is weak and becomes susceptible to the disease. You can help keep the grass strong by fertilizing only when the grass needs it: during the cool months for fescue and during the warm months for Bermuda grass.

WATERING Never water in the early evening. The best time to water is in early morning. Turfgrass is much more susceptible when it has lush, green growth plus warm nighttime temperatures. Warmth at night can not be avoided but lush growth can be moderated. The second step is to water at the right time. Since brown patch needs 14-16 hours of wet leaf surface to reproduce itself, water only after the dew has dried in the morning. An alternative is to water after nightfall. Since the grass is wet with dew anyway, watering in the dark does not unnecessarily extend the wet period.

FUNGICIDES If you are absolutely sure you have brown patch, the disease can be controlled with fungicides. Look online for products labeled for brown patch control. Although they are effective, their cost may cause you to reconsider their use. To cure brown patch in a lawn requires an application of fungicide every 14 days. A lawn fungicide costs approximately $20 per 1000 square feet per application. For a typical 5,000 square foot lawn, that comes to $100 every two weeks. Let your pocketbook be your guide!

POSITIVE IDENTIFICATION Obviously, it would be nice to have a positive identification of a disease before you decide on the best course of action. You can get that positive ID from your local Extension office (contact your county Extension office). Bring them a sample of your sick grass; it will be sent, free of charge, to the state disease lab in Athens for identification and treatment recommendations.

Q: I had brown patch disease throughout my lawn this summer. Can I put anything in the soil to eliminate the disease?

A: A one word answer: “No”. The fungus spores of brown patch are in the soil all of the time. They can not be eliminated. You only have a problem with brown patch when the grass becomes susceptible to it – because of drought stress or over-fertilizing or over-watering. All three of those conditions are under your control. If you water deeply once each week during dry weather and avoid fertilizing after May, brown patch won’t be nearly the problem it has been.

Remember that control and management of the disease are key. Don’t wait until you need a fungicide. Use fertilization, watering and mowing properly to avoid brown patch.

LAWN DISEASE ID

If you suspect that you may have a turf grass disease, your sampling procedure is critical in order to get an accurate diagnosis. Go to the suspected disease area. Find where the live grass meets some dead grass. This is called the disease margin area. You need to cut a 4 X 4 inch square that has half dead grass and half live grass in it. Include the roots. Do not allow the sample to heat, do not allow the sample to dry out. Place in a paper bag or plastic bag which is not sealed. If you cannot bring the sample in the same day you cut it, it is best to refrigerate it. Take it to your local county Extension office. They would prefer to get the sample on Monday or Tuesday so that they can mail it to the plant disease lab without any delay in the mail. Results will be mailed to you in about 10 days.

Q: We have a large spot in our yard where the grass won’t grow. We have Emerald zoysia sod in the rest of the lawn but in this same spot, year after year, the zoysia dies in the winter. What should we do to the soil to make the zoysia grow there?

A: When grass won’t grow in a sunny area, I look for two things: compacted soil and/or soggy soil. Earth that is too hard simply will not let grass roots penetrate deeply enough to keep the plant happy. If the roots can’t explore several inches of soil, they can’t get the moisture or nutrients needed in times of stress. If the soil stays too wet for extended periods, the roots similarly fail to thrive.

In both cases, lack of oxygen limits how deeply the roots can go. So my first suggestion is that you dig up the soil in the dead spot to a depth of six inches, perhaps adding some bagged manure to the earth, rake it smooth and lay more sod. Second, observe the spot after a rainfall or after you irrigate. Does water accumulate there? Can you redesign the water flow so it passes quicky over your yard? If you correct the rooting zone under the sod, I think your problem will be solved.

Tags For This Article: disease, zoysia

Zoysiagrass Yearly Maintenance Program

Zoysiagrass is an important turfgrass used throughout the southern regions of the United States and into the transition zones where both cool-season and warm-season grasses are adapted.

The improved turf-type zoysiagrass will produce a dense, low growing turf that has a slow lateral growth but normal leaf growth. There are two types of leaf blade textures with zoysiagrass: fine and coarse-bladed. Because of its leaf blade stiffness, zoysiagrass can be difficult to mow, and the mower blade will need to be sharpened frequently throughout the growing season. See HGIC 1212, Zoysiagrass for additional information on care and varieties.

Producing a yearly maintenance calendar for managing turfgrass consistently year after year can be difficult in a state with such a diverse climate as South Carolina. Because of this, it will be important to monitor temperatures and apply the needed management practices based on that year’s climate. Important times to monitor the weather are late winter or early spring when the turf is coming out of dormancy and early fall when first frost are forecasted. Last frost dates and first frost dates can vary by several weeks to a month from the coastal areas of South Carolina to the foothills of the Upstate.

This turfgrass maintenance calendar may be used on turf growing throughout the state; however, management practices will need to be adjusted based on the year’s climate and the region where the turf is grown.

January through April

Mowing: Mow the lawn slightly lower than the regular summer mowing height of 1½ to 2 inches. The mower setting should be around 1 to 1½ inches high. Be careful not to set the mower too low, as it may scalp the lawn. This should be done just before the time of lawn green-up, which usually occurs during late April or early May. If possible, use a mower with a bagger to collect the clippings and remove any dead material left from winter dormancy. Alternatively, the lawn can be hand raked to remove the excessive dead leaf material from the lawn surface. Grass clippings decompose quickly and do not contribute to thatch.

Zeon zoysiagrass is a fine-textured turfgrass that makes a beautiful, dark green, shade- & drought-tolerant lawn.
Joey Williamson, ©2018 HGIC, Clemson Extension

A sharp mower blade will cleanly cut the grass blades as opposed to tearing the leaves. Dull mower blades rip rather than cut the grass blades. The resulting ragged ends on the blades make the grass more susceptible to diseases. Typically, sharpen the mower blade after every 15 thousand square feet of lawn mowed. If ragged ends of leaf blades become apparent after mowing, the blade needs sharpening.

The date of initial turf greenup can be quite variable. In the coastal and more Southern regions of South Carolina, this generally will occur sometime during April, but further inland, this may be as late as mid-May. It is not unusual for zoysiagrass to green up and be burnt back several times during the late winter or early spring due to late season frosts. Because of possible injury to the lawn and the potential fire hazard, do not burn off zoysiagrass to remove excessive debris. For more information on mowing, refer to HGIC 1205, Mowing Lawns.

Thatch Removal: If a thatch layer becomes a problem, use a dethatcher or vertical mower to remove it. Consider dethatching zoysiagrass when the thatch layer is greater than 1 inch. This turfgrass species normally produces a hefty thatch layer, so a little thicker thatch than for other turfgrass species is acceptable. For best results, use a dethatcher with a 2- or 3-inch blade spacing set a ¼-inch depth. Do not use a power rake with a 1-inch blade spacing, as severe turf injury may result. Use a lawn mower with a bag attached or hand rake to collect and properly dispose of the turf material pulled up. For more information on thatch removal, see HGIC 2360, Controlling Thatch in Lawns.

Aerification: Core aeration is the process of punching small holes in the turf and into the soil to alleviate compaction, thus allowing air to get to the root system. This will help to correct problems associated with poor infiltration and drainage. Once the threat for frost has passed, lawn aerification may be combined with dethatching to alleviate any soil compaction problems.

However, if a pre-emergent herbicide was applied late February to mid-March, postpone any cultivation practices that will disturb the soil until just before the next pre-emergent herbicide application date. Pre-emergent herbicides create a barrier that keeps weed seeds from germinating. Disturbing the soil after an application will allow weeds to emerge through this barrier. For more information on aerification, refer to HGIC 1200, Aerating Lawns and HGIC 1226, Turfgrass Cultivation.

Weed Control: To control crabgrass, goosegrass, sandspurs, and other summer annual weeds, apply a pre-emergent herbicide early in the year. Approximate times are mid-February in the coastal and central areas and mid-March in the piedmont/mountain areas. A second application is needed approximately 8 to 10 weeks after the initial application to give season long control of annual grassy and broadleaf weeds.

Apply a post-emergent herbicide as needed to control existing winter grassy and broadleaf weeds. In general, do not apply post-emergent herbicides during the spring green up of the turf. If a weed problem begins and the grass has begun to green with warmer temperatures, wait until the grass has fully greened before applying a post-emergent herbicide. In the meantime, mow and bag the weeds. Zoysiagrass is sensitive to certain herbicides during hot summer temperatures. Follow label directions for use of any herbicide and use with caution during these times. For more information on weed control, please see HGIC 2310, Managing Weeds in Warm-Season Lawns.

Insect Control: Cold winter temperatures will usually keep insect problems in zoysiagrass at bay. As temperatures start to warm in late spring, monitor for mole cricket activity. If mole cricket activity is observed, apply a lawn insecticide if damage is excessive. If the damage is minimal, wait before applying an insecticide. This is not the best time to apply an insecticide for insect control because of cool soil temperatures and reduced insect activity. However, an early warm-up can lead to significant mole cricket activity. Heavy populations can be reduced through appropriately timed insecticide treatments during this period. For more information on mole crickets, see HGIC 2155, Mole Cricket Management in Turfgrass.

If grubs (the white larvae of beetles, such as Japanese beetles) have been a problem in previous years, monitor the grubs by cutting a square foot piece of sod on three sides and peel it back. If more than six grubs are found under the sod piece, apply a lawn insecticide labelled for grub control according to label directions. For more information on white grub management, see HGIC 2156, White Grub Management in Turfgrass.

Fertilization: Fertilization of zoysiagrass should be based on soil test results, and this is a good time to test soil. However, fertilizers containing nitrogen should not be applied during this period unless the lawn is located along the coast and no frost is predicted. If new turfgrass growth is encouraged by fertilization during the early spring and this is followed by a late frost, the result can be significant damage to the lawn. See HGIC 1652, Soil Testing for instructions on how to properly do a soil test.

Irrigation: During dormancy, water the lawn to prevent excessive dehydration. Winter desiccation can be a problem during dry winters. Watering to prevent drought stress can help eliminate turf loss during winter.

Most areas of South Carolina receive enough rainfall during the winter to avoid winter desiccation of lawns. However, this is not always the case. Monitor the winter rainfall on a regular basis and apply water to the turf if no measurable rain occurs over a 3 to 4 week period. This is especially important if warm, bright days preceed days forecasted to be in the low 20’s or colder. The added moisture in the soil will help keep the growing points of the turf warmer, preventing crown death.

To manage a lawn, it is important to know the soil texture in the top foot of soil. Sandy soils do not hold moisture well since they drain freely and dry out faster. Clay soils, however, will hold moisture for a longer period. Do not allow the lawn to stay excessively wet if the lawn has a clay soil. If the soil stays saturated all winter, this can cause many other problems. A soil probe can be used to monitor the soil moisture. For more information, refer to HGIC 1207, Watering Lawns and HGIC 1225, Conserving Turfgrass Irrigation.

May Through August

Mowing: The ideal mowing height for zoysiagrass cultivars can range from 1 to 2½ inches depending on your specific site and management. For most zoysiagrass cultivars, turfgrass growers recommend a mowing height of 1½ inches. In partial shade, mow zoysiagrass at 2 to 2½ inches. Mowing heights below 1 inch will require a reel type mower to achieve satisfactory results, and with zoysiagrass, a reel type mower will give better results at any height.

During periods of environmental stress, high temperatures, or a lack of rainfall, slightly raise the mowing height until the stress is eliminated. Always mow with a sharp mower blade and use a mulching type mower to leave the clippings to decompose on the lawn. The mower blade will need sharpening on a regular basis, which is usually about once a month. If the bagger is picking up soil, especially sand, the mower blade may need to be sharpened more often than once per month.

Fertilization: Always fertilize and add lime or sulfur based on a soil test. Zoysiagrass will grow best at a pH of 6 to 6.5. If a soil test shows a higher pH, sulfur can be applied to lower it. Apply 5 pounds of pelletized sulfur per 1000 square feet of turf. Apply sulfur only when the air temperatures are below 75 °F. In 3 months, recheck the soil pH to see what change was made. It may take several years for a large pH change to occur. Soils in the Upstate are typically acidic and usually do not need sulfur applications, but they likely may benefit from lime applications.

Zoysiagrass lawns should receive 2 to 4 pounds of actual nitrogen per growing season per 1000 square feet of turf. The higher rate may be used on zoysiagrass lawn grown on sandy soils, and the lower rate for lawns grown on clay soils. An application of a soluble iron product will enhance the green color without creating excessive growth.

Early Summer: Apply ½ to 1 pound of actual nitrogen per 1,000 square feet early May after the lawn fully greens up. The rate will depend on soil type. A soil test will help determine if a fertilizer containing phosphorus, the middle number in the fertilizer analysis, is sufficient for the lawn. See the section on fertilizer calculations below to determine how much granular fertilizer product should be applied.

Mid-summer: Depending on the soil type, fertilize with ½ to 1 pound of actual nitrogen per 1,000 square feet in June or July using a fertilizer that is also high in potassium, such as a 15-0-15. The need for phosphorus is determined by a soil test.

Late Summer: Depending on the soil type, apply ½ to 1 pound of actual nitrogen per 1,000 square feet before August 15 using a fertilizer that is also high potassium, such as a 15-0-15. It is important for the soil to have sufficient potassium, especially late in the growing season as the grass enters dormancy. Potassium is important for disease resistance and cold weather hardiness.

Nutrient Deficiencies: A yellow appearance during the growing season may indicate an iron deficiency due to excessive soil phosphorus and/or a high soil pH. A long-term approach is needed to correct either cause, but iron can be added to quickly enhance turf color between the spring and summer fertilizer applications.

Note: A yellow appearance may also arise in early spring. This could indicate an iron or manganese deficiency due to soil temperatures lagging behind air temperatures, high pH soils, or high phosphorous levels. Spraying with iron (ferrous) sulfate) at 2 ounces in 3 to 5 gallons of water per 1,000 square feet or applying a chelated iron product will help to enhance turf color. Fertilizing with a micronutrient fertilizer, such as manganese sulfate, can help alleviate manganese deficiencies. However, as the soil temperatures start to climb, the yellowing should slowly go away. Lime or sulfur may also be added if a soil test indicates a need. Be aware, it could take several months for lime and sulfur applications to begin to affect the soil pH.

Fertilizer Calculations: To determine amount of granular fertilizer needed to apply ½ pound of actual nitrogen per 1,000 square feet, divide 50 by the first number on the fertilizer bag. To determine amount of product required to apply 1 pound of actual nitrogen per 1,000 square feet, divide 100 by the first number on the fertilizer bag. This will give the number of pounds of fertilizer product to apply to 1000 square feet of turf. See HGIC 1201, Fertilizing Lawns, for more information.

Irrigation: Water to prevent drought stress. Monitor the lawn on a regular basis to assess the need for irrigation. When the entire lawn appears dry, apply ¾ to 1 inch of water the next morning. Wait to irrigate again when the lawn shows moisture stress. There are several ways to determine when the lawn needs watering. One way is to monitor the lawn daily. When the turf begins to dry, it will appear to have a bluish color. Another method is to walk across the lawn late in the evening. If the grass blades in the footprints rebound, there is plenty of moisture in the turf. If the grass in the footprints do not rebound, then water the next morning.

The irrigation interval will vary from site to site depending on the environmental conditions at that site and soil type. The general rule to turfgrass irrigation is to water “deeply and infrequently”. Localized dry spots or hot spots can be watered by hand as needed, but only run the irrigation system when the entire lawn is dry. For more information on turfgrass watering, see HGIC 1225, Conservative Turfgrass Irrigation.

Insect Control: There are various insect pests that may attack zoysiagrass during the summer months. Mole crickets, grubs, ground pearls, as well as nematodes can cause considerable damage. Each pest problem will have its own management strategy and is usually handled with cultural and chemical controls. However, there can be exceptions. Mole crickets and grub eggs will usually hatch mid-summer. An insecticide application targeted at the smaller nymphs is the most effective control even if damage has not yet occurred. If either of these insects were a problem early in the season, apply an insecticide mid-July to control the younger immature insects.

If an insect problem occurs, it is important to positively identify the problem and select the appropriate insecticide to apply. Contact the local County Extension Office or the Home & Garden Information Center for positive identification and proper management strategies. For more pest management information, see HGIC 2156, White Grub Management in Turfgrass, HGIC 2155, Mole Cricket Management in Turfgrass, and HGIC 2157, Bermudagrass Scale, Rhodesgrass Mealybug & Ground Pearl.

Disease Control: The most common diseases that may occur on zoysiagrass during the growing season are large patch, formerly known as brown patch, and dollar spot. Large patch and dollar spot are fungal disease that will occur during warm, wet weather. Since they are fueled by moisture, it is important to use proper watering practices, as well as providing adequate soil drainage.

If the turf does stay wet, circular areas may start to develop and slowly grow in size. Diseased turf with dollar spot range from 2 to 6 inches in diameter, but large patch may result in affected areas that may grow to several feet in diameter. The center of a large area may start to green. In heavily infested turf, the areas may grow together and thus will not appear circular. If the turf at the edge of the dying area shows a smoky brown, rotted appearance, it will be necessary to apply a fungicide treatment. Overall, proper water management and thatch control is essential to curtail large patch and dollar spot problems. To help reduce disease problems, fertilize the zoysiagrass lawn according to recent soil test recommendations and water infrequently.

Weed Control: A selective, annual grass or broadleaf weed control pre-emergent herbicide that is labelled for use on zoysiagrass and applied during late winter and spring will reduce many weeds the following summer. If a pre-emergent herbicide was not applied, then the resulting weeds will need to be controlled using post-emergent herbicides

Broadleaf summer weeds, such as spurge and annual lespedeza, are controlled by using a 3-way, broadleaf weed herbicide. These 3-way mixes typically contain 2,4-D, dicamba, and mecoprop.

Many grassy weeds are controlled by quinclorac or fluazifop applications. Nutsedges are controlled by imazaquin, bentazon, or sulfentrazone. If summer annual grassy weeds are a problem, pre-emergent herbicide applications in late winter and early spring may be the best choice.

Do not apply herbicides in summer unless the temperature is below 90 °F. Use herbicides with caution as the turf is emerging from winter dormancy. Do not mow the lawn for 3 days prior to or 2 days after herbicide application. For best control and to lessen the chance of turfgrass injury, always apply herbicides to turfgrass and weeds that are actively growing and not suffering from drought or heat stress. As with all pest control, proper weed identification is essential. Contact the local County Extension Office or the Home & Garden Information Center for identification and control of weeds in the lawn. For more information on weed control, see HGIC 2310, Managing Weeds in Warm Season Lawns and HGIC 2312, Nutsedge.

Renovation: Replant large bare areas in May using sod, plugs, or sprigs (5 bushels per 1,000 square feet). Zenith zoysiagrass is available as seed and is best planted in late spring or early summer. For more information, refer to HGIC 1204, Lawn Renovation.

September through December

Mowing: Continue to mow the zoysiagrass lawn at the normal mowing height until the weather starts to cool in the fall. Once nighttime temperatures fall below 70 °F, slightly raise the mower to allow more leaf surface. This will allow the turf to become acclimated by the time the first frost occurs.

Fertilization: Do not apply nitrogen at this time. Lime or sulfur may be added if recommended by a recent soil test. Potassium, commonly known as potash, may be applied to enhance winter hardiness if a soil test indicates insufficient levels of potassium. Apply 1 pound of potash (K2O) per 1,000 square feet 4 to 6 weeks before the first expected frost by using 1.6 pounds of muriate of potash (0-0-60) or 2 pounds of potassium sulfate (0-0-50) per 1000 square feet.

Irrigation: In the absence of rainfall, continue to water to prevent drought stress. After the lawn has become dormant, water as needed to prevent excessive dehydration. This is especially important if warm, bright days preceed days forecasted to be in the low 20’s or lower.

Insect Control: Any insects that were missed during the nymphal stage in the summer will have grown to a size where damage is occurring. Apply an insecticide to reduce the population and reduce further turf damage. This is best done before the first frost.

Disease Control: For disease control, especially large patch, it is extremely important to treat with fungicides during the fall months. With warm temperatures through September and the possibility of excessive rainfall that may occur during that period, diseases can spread rapidly. However, with cooler nights and shorter day lengths, control can be quite difficult because of slow turf recovery during this time. Turf weakened by disease in fall will be slow to recover in the spring; therefore, fungicide applications are needed to control disease before the grass goes dormant. In certain situations where large patch has been prevalent yearly, a preventative fungicide application may be needed starting in early October to stay ahead of the disease. For more information on disease control, please see HGIC 2150 Brown Patch & Large Patch Diseases of Lawns.

Weed Control: Many winter annual grassy and broadleaf weeds can be managed by applying a pre-emergent herbicide in September with a second application 8 to 10 weeks later. Follow all label directions on the product for use and application rate. Granular herbicides must be watered into the soil soon after application. Follow label directions as to post application watering.

Broadleaf weed herbicides can be applied as necessary for control of chickweed, henbit, and other cool-season broadleaf weeds. Selective herbicides can also be applied during winter for control of annual bluegrass and other winter annual grassy weeds. Contact the local County Extension office or the Home & Garden Information Center for weed identification and control measures. See for HGIC 2310, Managing Weeds in Warm Season Lawns for more information.

Zoysia Lawn Care

Whether you live in Georgia, Alabama, or Illinois, a beautiful green lawn is worthy of admiration. It takes a lot of hard work and skill to maintain one. To raise gorgeous grass, you’ve got to have a comprehensive knowledge of the species and know precisely what it needs to thrive. Alternatively, you can find yourself an expert lawn care service and let the professionals take care of everything.

It is a particularly useful option if you have a zoysia grass lawn. This tough, hard-wearing species is quite the survivor, but it is sensitive to temperature fluctuations. Even relatively small changes can cause an unsightly loss of color, so it is best suited to the warmer, southeasterly regions. It is also worth considering professional lawn care because it is a great way to ensure that zoysia grass stays green all year round.

This guide to caring for a zoysia lawn will give you some great tips on watering, fertilizing, mowing, and more.

A Quick Description of Zoysia Grass

The zoysia species is not native to the United States. However, it has been here for a long time. It was first introduced in 1895, right around the time that the popularity of neatly mown and manicured lawns was starting to soar among homeowners. It is a warm-season grass that flourishes in hotter regions, stretching from the Atlantic to the Midwest.

There are three major species of zoysia grass. They include Japanese lawn grass, Mascarene grass, and Manila grass. Japanese lawngrass (or japonica) is the most common variety across the southeast. The species is often confused with Bermuda grass, but zoysia is stiffer to the touch and can withstand a greater degree of downward pressure.

The Advantages

The most significant benefit of choosing zoysia over other species is that it requires very little lawn maintenance in the right conditions. If it is planted in a slightly colder area, this might not be so accurate, but zoysia is generous if given an optimal environment. For example, it is highly water-efficient and can thrive with just half an inch of rain each week.

It also has a slower rate of growth than some of the other species. This means that it can be mowed less often. While most zoysia lawns struggle with discoloration issues in colder climates, they are hard to kill off. Instead of dying, they enter a dormant state and can be brought back fairly quickly when the warm weather returns.

The Disadvantages

Ironically, some of the best things about zoysia grass are also the things which make it a frustrating choice for a lawn. For instance, its slower rate of growth means that it is low maintenance, but it can be tough to repair damaged sections. It may take a long time for a reseeded patch to develop and, sometimes, the superior option is to go straight for new turf.

For the same reason, zoysia can be hard to establish. Most lawn care services recommend the use of sod and plugs if you want to create an entirely new lawn. Thatch is another issue that lawn aeration can help with. Ultimately, it is challenging to keep zoysia grass green throughout all four seasons, due to its sensitivity to temperature change.

Mowing

Many amateur gardeners are unaware of the fact that zoysia has a fairly high silica content. This means that, the longer the blade, the tougher it is to cut. To prevent your mower from sawing at the blades, rather than slicing them neatly, it needs to be as sharp as possible. If you do not have a high-quality mower, it might be best to let a professional lawn service help.

When the blades are sawed at, they have ragged ends, and this makes the lawn look yellow. Therefore, the ideal tool is a very sharp reel mower. You should never cut zoysia below an inch. The golden window is somewhere between one and two inches high. This species grows slowly and can be mowed up to ten times less (per season) than other varieties of grass.

Watering

Similarly, zoysia needs far less water than other grass species. In fact, it doesn’t usually need manual irrigation unless there has been very little rainfall. As explained, a minimum of half an inch of water is required, so keep an eye on this if you do live in one of the much drier regions. It is worth noting that sandy soil types often need slightly more moisture.

As excessive watering can cause damage to the roots, it is a big faux pas. Generally, trusting your own eyes is good enough. If the soil starts to dry out or crack, there hasn’t been enough rain, and you need to introduce some water.

Sunlight Requirements

Most types of zoysia are wonderfully hardy and can flourish in shady conditions as well as in full sunlight. Crucially, however, if you are going to plant zoysia in the shade, it needs to be somewhere which gets at least three to four hours of direct sunlight each day. It may be tough, but it cannot live without any light at all.

Keep this in mind, because it is the most common reason why some sections of lawns (around trees, for example) start to turn yellow. When planted in full sunlight, the species thrives and is heat tolerant up to temperatures of 120 degrees Fahrenheit. It is just another one of the reasons why, in the right conditions, zoysia is a durable and rewarding choice.

Soil Requirements

Amazingly, zoysia can grow in almost all soil conditions. It can even withstand salty, coastal soils which is quite rare among the common lawn grasses. What it means for homeowners is that the species is impervious to things like pavement salt. If you have a driveway right next to the lawn, you can salt it in the winter without worrying about harming the grass.

Similarly, drier, sandy soils are sufficient too. They allow for rapid root development because there are more airspaces in which the root system can travel. Zoysia doesn’t grow quite as fast in clay soils, but it can still survive. The roots are very strong and, usually, they manage to push through even very dense soil material.

Fertilization

While zoysia grass can grow in a variety of soil conditions, it prefers a pH of between six and seven. You can, of course, use lawn fertilization techniques to achieve this balance. Most lawns do require a fertilization treatment once in spring and again in summer. Use approximately 15lbs of complete fertilizer per 1,000 square feet of grass.

For supplemental feeding, apply 2-3lbs of nitrogen over the course of the growing season on spaced out occasions. Ideally, leave 50-60 days between each treatment. It is worth remembering that the presence of trees can alter the pH of the soil, so think about testing shaded sections. You may need to add a little sulfur or pulverized limestone to these areas.

Weed Control

It is true that zoysia grows densely packed together and that this makes it harder for weeds to penetrate and take hold. However, it does not mean that the grass will thrive without any outside intervention. In fact, the species does require topical treatment with herbicides if you want to keep it entirely weed-free.

The best approach to weed control is to apply a pre-emergent herbicide. If used periodically in the spring and autumn, it eliminates almost all weeds before they have a chance to emerge from the ground. The most common types, for zoysia lawns, are broadleaf and grassy weeds. They include chickweed, hairy bittercress, wild mustard, prickly lettuce, and dead nettle.

Pest Control

It is a common misconception to assume that insect-killing chemicals are the best way to tackle pests in zoysia lawns — this not the case. If you want your lawn to grow strong and healthy, you need to establish a precise, consistent system of care. The right kind of mowing, fertilization, and aeration has a significant impact because it makes the grass less tolerable.

By relying on proper maintenance, as opposed to insecticides, you’re also allowing skilled pest hunters (like nabids, big-eyed bugs, and anthocorids) to do the work on your behalf. The alternative is that you end up killing the good bugs too and leaving the lawn unprotected, which, in turn, intensifies the need for chemical treatments.

You should keep a close watch on the lawn as your own eyes are an invaluable tool. Check the grass for signs of damage once per fortnight in the winter and once per week throughout the rest of the year. Be careful not to cut the grass too short, as this will make it more vulnerable to pests. Similarly, take care not to over-fertilize and regularly aerate to penetrate the thatch.

Repairing Problem Areas

While reseeding is always the cheaper option, if you need to repair damaged sections of a lawn, it can take quite some time for zoysia seeds to develop. For this reason, many lawn care providers recommend using turf, plugs, or sod for a faster result. It is, of course, entirely up to you, but fully developed grass is the better choice for an immediate fix.

Zoysia sod can be installed at any time of the year, but May through June is the optimal window. This is a time when the species grows at its quickest rate. It is strong, robust, resilient, and naturally resistant to pests and weeds. Again, zoysia can thrive even in poor planting conditions but do break up the soil to a depth of between six and eight inches if possible.

Remove all surface vegetation and debris. Then, fertilize the target area with one pound of complete lawn fertilizer for every 100 square feet of grass. Finally, combine two to three inches of organic matter (an aged compost is ideal) with the top six inches of soil. The perfect time to install zoysia sod is in the early morning before the sun gets a chance to heat the ground.

Final Thoughts on Caring for a Zoysia Lawn

If you are blessed with hot, dry conditions, zoysia grass might just be your new best friend. It can be a tricky customer at times, especially considering its tendency to yellow in response to even slight temperature changes. However, it is exceptionally hardy, and you couldn’t ask for a tougher lawn species.

Don’t forget that the support of a professional lawn care service is a great asset to have if you find care and maintenance a daunting task. Expert lawn teams take care of everything from mowing to fertilizing, pest control, soil regulation, thatch removal, and more. They can guarantee a lush, beautiful lawn all year round.

Bare Patches in Zoysiagrass Lawn

We have bare spots all over our zoysia grass. We had a service man come to spray it, but that didn’t do anything. Should we add new soil, loosen the present soil and re-sod?

Dead spots can be the result of insect or disease problems. Knowing the culprit is necessary to select the best treatment. Sprays only work if the right product is used at the right time. Avoid problems and reduce the need for chemicals with proper care. Avoid excessive fertilization that can lead to disease. Fertilize the lawn when it is about 50% green. If desired you can fertilize 7 weeks later. Use a low nitrogen slow release fertilizer to reduce the risk of burn and disease that often attacks lush succulent growth. Keep your zoysia lawn at least 1 ½ inches tall and remove no more than 1/3 of its total height with each mowing. Taller grass forms deeper roots and is more pest and drought resistant. With proper care the healthy grass may fill in the dead areas. Otherwise try seeding or planting sprigs in these bare spots. Consult your local extension service or lawn care professional for proper diagnosis if the problem persists.

7 Steps to Avoid Zoysia Patch

Zoysia patch is a soilborne disease that can affect all cultivars of Zoysia grass. Symptoms of this disease occur when the fungus is present and environmental conditions promote its growth. It is most evident in areas of the lawn that have thick thatch, poor drainage, shade and restrictive air circulation.

Zoysia patch grows in the cool weather of spring and fall. It begins as small circles of 6 inches across and can grow as large as twenty feet in diameter. Patch interior becomes sunken, and injured turf appears thin with a tan, yellow or orange color. A useful diagnostic feature in the field is a brilliant
“orange firing” of the expanding outer ring, whichindicates active infection.While the fungus does not kill the roots of the Zoysia grass, it may take months for affected areas to recover after proper treatment. Without proper fungicide treatment, the problem does not “go away.” It gets worse.

This disease attacks slowly-growing, warm-season grass in cool, wet weather, and is most common on semi-dormant or grass that is going into or emerging from dormancy. Damage can persist through cool, wet conditions and often lasts until warmer spring or summer conditions allow for recovery and active regrowth.

The best way to treat Zoysia Patch is to prevent it.

Tips For Preventing Zoysia Patch

Here are the steps you can take to help avoid this disease:

  1. Always bag and remove clippings when mowing your Zoysia lawn.
  2. Core-aerate your lawn once per year to improve drainage.
  3. Don’t mow when grass is wet.
  4. Water deeply once per week between 5 and 10 am.
  5. Prune trees and shrubs to raise the canopy and to improve light and airflow.
  6. Maintain proper nitrogen levels, especially on damaged turf.
  7. Resolve any drainage issues.

Think you may have Zoysia Patch? We offer preventative and curative Zoysia Patch treatments consisting of 3 applications per year. Give us a call or email us!

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Categories: Lawn Care

Diseases That Commonly Affect Zoysia Grass

Zoysia grass is a drought-resistant warm-season grass. Dollar Spot, Rust and Brown Patch are some of the most common diseases that could damage the Zoysia grass. In this article, we would find out more about these diseases along with ways to prevent them.

Zoysia is a genus of creeping grasses in the Poaceae family. Native to certain regions of Asia and Australasia, the species under this genus include: Zoysia japonica, Zoysia matrella, Zoysia minima, Zoysia macrantha, Zoysia macrostachya, Zoysia sinica and Zoysia pauciflora. Emerald Zoysia, which is a hybrid between two species called Zoysia japonica and Zoysia tenuifolia, is commonly used on sports turf, golf courses and high-quality lawns. Belaire Zoysiagrass, El Toro Zoysiagrass, Cashmere Zoysiagrass and Meyer Zoysiagrass are other varieties that have been developed. Zoysia grass is a hardy grass that grows extremely well during the summer months. Since it is drought-resistant, watering requirements are lower in comparison to other turf grasses. It is relatively less susceptible to diseases, but one must always watch out for the signs of common diseases. In this article, we would learn about some of the common Zoysia grass diseases along with ways to lower the incidence of such diseases.

Diseases that Affect Zoysia Grass

However hardy Zoysia grass may be, problems can arise if this grass becomes infested with insects. It would also be difficult to maintain this grass if weeds start competing with it for nutrients. Thatch refers to the interwoven layer of dead tissues or partially decomposed plant material like stems, roots and leaf sheaths that lies between the grass and the surface of the soil. If not controlled, thatch may attract disease-causing organisms. Emerald Zoysia, which is one of the popular varieties, is quite susceptible to thatch and winter injury. So, attention must be paid to thatch management as well. It is definitely an essential part of Zoysia grass maintenance. Scroll down to learn about the common diseases and use the following tips on Zoysia grass care to prevent an outbreak of such diseases.

Dollar Spot

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Dollar spot is a very common grass disease. The characteristic sign of this disease is the development of small straw-colored spots. These spots appear on the individual leaves and are almost the size of a silver dollar. If the infected leaf blades are checked during the early hours when the grass is still wet with dew, one may also be able to spot white thread-like hyphae of the disease-causing fungus. Sclerotinia homeocarpa is a fungus that is believed to be responsible for causing dollar spot. However, studies have revealed that fungus from Lanzia or Moellerodiscus genus could also cause dollar spot. This disease is likely to develop if the humidity is high and the soil moisture content is low. More often than not, dollar spot develops if adequate amounts of fertilizer are not applied. A timely application of a correct blend of fertilizers will certainly prove beneficial in preventing dollar spot. Dollar spot could also develop if mowing is not done in the right manner. Besides following the right mowing practices, one should also pay attention to thatch management and weed control. The application of a fast release nitrogen fertilizer can help in undoing the damage caused by dollar spot.

Fusarium Patch

Fusarium patch, which is also known as pink snow mold, is a disease that is caused by a fungus called Microdochium nivale. This disease is characterized by the development of yellow spots. It usually occurs when the snow that covers the lawn starts to melt. The yellow spots that are initially 1-3 inches in diameter, then turn brown and form rings that are 12 -24 inches wide. Fusarium patch disease is most likely to damage lawns or turf during autumn and winter. Poor management of thatch can also increase the risk of this fungal disease. Soils that are not well-drained are most likely to develop thick thatch. It is essential that you use an aerifier so as to allow air to penetrate into the compacted soils. You could also use a vertical mower to mechanically remove thatch. Extended periods of drought can also increase the likelihood of infestation, which is why deep watering once every week may prove beneficial. The best time of watering this warm-season grass is during the early hours. Application of a suitable fungicide will also help in controlling the infestation.

Rhizoctonia Blight

Rhizoctonia blight, which is also known as brown patch, is one of the most common diseases that can cause a lot of damage to this grass. Brown patch, as the name suggests, is characterized by the development of light brown circular patches on the affected area. The outer edge of such patches is usually grayish-black in color. The diameter of these patches could lie anywhere between 2 to 3 feet. This fungal disease is most likely to occur when the grass stays wet for a long time. If you do notice signs of this disease, make sure to spray a garden fungicide that contains sulfur. Refrain from watering the lawn in late afternoon especially when it is hot. Make sure that there isn’t excessive buildup of thatch. Once the grass is established, applying 1-2 pounds of nitrogen per thousand square feet annually between May to August should suffice. Excessive application of nitrogen fertilizer, especially during summer may also increase the risk of infestation. So, make sure that you apply nitrogen fertilizer as per the requirements.

Leaf spot is another disease that could damage Zoysia grass. It is caused by a fungus called Bipolaris sorokiniana. This fungal disease not only affects the leaves, it could also damage the root and the crown of Zoysia grass. The characteristic sign of this disease is the development of spots that have purplish-black borders. The roots as well as the crowns may also become dark brown to black due to the infestation. Once the leaf blades begin to turn brown, the infected part is most likely to wither and die. The best way to prevent such an infestation is to refrain from using excessive amounts of nitrogen fertilizer. The most suitable time of fertilization is between May to August. Proper mowing and watering practices must also be followed. It would be best to mow your lawn to a height of ½ to 1½ inches. Low mowing promotes the growth of a dense mat. You could also use a mulching mower that can evenly distribute the grass clippings. Do make sure that you mow your lawn when it’s dry.

Pythium Blight

Pythium blight is a fungal disease that is caused by a fungus called Pythium spp. This disease is characterized by the development of circular or irregular water-soaked patches of grass. These patches are usually 6 to 12 inches in diameter. While the grass appears to be greasy in the initial stages, it begins to dry with the progression of the disease. The color of the leaf blades would also change from green to reddish-brown. Soon the areas that are affected by the disease wither and die. If there is a high level of humidity, a gray-colored moldy growth may develop on the damaged areas of the grass. Following a fungicide program is the best way to prevent this fungal disease.

Powdery Mildew

Zoysia spp. is one of the turf grass species that could get infested by powdery mildew. The signs of powdery mildew are most likely to appear in areas that have a dense shade. High relative humidity and excessive use of nitrogen fertilizer could also increase the risk of powdery mildew. If the grass gets infected with powdery mildew, the infected areas develop white-colored powdery patches. If steps are not taken soon, the leaf blades may turn yellow and die after some time. Since this disease is common in heavily shaded areas, it would be a good idea to trim the surrounding trees so as to allow light. Excessive watering must also be avoided. When it comes to watering this grass, one inch of water in a week should suffice. However, frequent watering may be required if leaf blades seem to be wilting due to hot weather. Spraying a garden fungicide that contains sulfur would also help. Using weed control products would also help in preventing growth of unwanted plants in the lawn.

Rust is another disease that may damage Zoysia grass. More often than not, rust develops when it is warm and humid. This disease usually affects lawn grasses in late summer. Improper mowing may also increase the risk of infestation. The development of reddish-brown spots on the leaf blades and the stem is the characteristic sign of rust. If the grass is infested with rust, one would be able to see reddish-orange dust in the air while mowing the lawn. As the disease progresses, the leaf blades may turn yellow and die. When it comes to prevention of rust, mowing the grass as per the recommended mowing height and applying adequate amounts of fertilizers and fungicides can certainly help.

Besides the aforementioned Zoysia grass diseases, other diseases that could sometimes affect Zoysia grass include slime mold, fairy rings and red thread. Since damage to Zoysia grass is most likely to occur due to infestation by different types of fungi, steps must be taken to prevent the growth of fungi. Insects such as chinch bugs, grubs, crickets, billbugs and sod webworms may also cause damage to the grass. So, be on a lookout for any signs of infestation. Though Zoysia is a drought-tolerant grass that grows best in warmer regions, extended periods of drought could sometimes make it susceptible to diseases. If the lawn is looking bad due to an infestation, you could use pigment-type colorants to dye it green. Since this grass is invasive, it can crossover or overtake the cool season grasses that may be growing alongside. While the cool season grasses would remain green in winter, brown-colored dead spots may develop in areas where Zoysia grass is growing. Moreover, once established, it is extremely difficult to remove. So do consider the climate and the growing conditions before planting this grass.

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