Although Zoysia grass is quite tolerant and hardy in some respects, it is also somewhat fragile when it comes to overwatering, mowing, and soil quality.
If your Zoysia lawn keeps turning yellow and dying off, don’t panic–we’ve got the solutions you need here.
Zoysia grass is especially prone to damage from overwatering and improper mowing, making it vulnerable to diseases like brown patches and pests like chinch bugs. Treat fungi and pests promptly with fungicides and pesticides, and keep your lawn well-fed, watered, and mowed with sharp blades.
Read on for an in-depth guide to determining the health of your Zoysia grass, what makes it so fragile, and the many ways you’ll be able to keep it healthy and strong for years to come, despite its occasionally fickle nature.
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How to Tell if Your Zoysia Grass is Dying
Zoysia grass usually turns yellow or brown at the tips once it dies off. Certain lawn diseases and a lack of water and nutrients, in general, will cause Zoysia to die off, usually in isolated patches, which eventually spread throughout the entire affected lawn.
Normally, Zoysia grass has a rich, bright green color when healthy and strong.
This makes it easy to tell when something is wrong with the amount of care and nutrients it’s receiving.
Dying Zoysia typically starts to turn yellow or pale brown at the tips, and gradually, this spreads in patches throughout the whole lawn.
Dying Zoysia also looks less thick and lush than usual.
Instead of the typical full, green coverage it’s known and loved for, you’ll notice more sparse, dead patches where growth is uneven, slower than usual, or, in severe cases, completely nonexistent.
Keep an eye out for any sudden patches of yellow or brownish grass, as this is almost always indicative of an issue with water, nutrients, or how often you’re mowing.
In some cases, it also indicates harmful lawn diseases or lawn pests.
Regardless of what’s causing the grass to die off, you’ll be able to tell pretty quickly as soon as something’s off simply by looking for dull, off-colored, thin patches.
What Makes Zoysia Grass Die?
Various improper conditions, diseases, and lawn pests will cause Zoysia to die off if not treated promptly. Zoysia is especially intolerant to excess water, cold weather, root rot, and certain types of fungi like Zoysia patch. It also does not fare well when mowed too short (below 1.5” inches) or unevenly.
Despite being known and loved for its relatively low-maintenance status, Zoysia is uniquely susceptible to several conditions, including pests like chinch bugs and lawn-destroying fungi.
In particular, it doesn’t handle excess moisture or heavy rains very well, and a few types of fungal diseases like Zoysia patch and rust are especially damaging to its roots.
Mowing, watering, and fertilizing it properly is essential to its overall health, meaning improper care is also a huge cause of damage many homeowners tend to overlook.
While Zoysia is quite drought-tolerant, this doesn’t mean it can go weeks on end without any water at all.
However, it also is very sensitive to overwatering, so finding the right balance (usually around 1” inch of water per week) is necessary to keep it hydrated but not overwhelmed.
Another common reason Zoysia tends to die off is being kept too short.
Although many grasses can thrive at lengths of 1” inch or even less, Zoysia looks and thrives best when kept at around 1.5” to 2” inches in height.
Additionally, if you mow with dull blades or mow it when it’s too moist, you risk tearing and damaging the blades of grass rather than getting even cut.
This leaves your lawn especially vulnerable to water and sun damage as well as fungi and lawn pests.
Always use a sharp reel mower or a well-maintained rotary mower with regularly sharpened blades to prevent damaging your Zoysia lawn.
How Do You Revive Zoysia Grass?
If you’ve determined your Zoysia grass is dying off, you’ll likely still be able to revive it, depending on how far it has progressed. If the cause is fungi or lawn pests, you’ll need to treat them appropriately before aerating, applying fertilizer, and reseeding the dying patches.
How well you’ll be able to revive dying Zoysia grass depends largely on how advanced the damage has become as well as the underlying cause (or causes) of the damage.
The most common causes of dying Zoysia grass are the following:
- Improper mowing practices, i.e., mowing too short/mowing with a dull blade
- Lawn fungi
- Lawn insect pests
- Compacted soil/poor aeration
In the case of overwatering, you’ll likely be able to simply hold off on watering for a while and add a 3-1-2 or 4-1-2 NPK fertilizer to allow your lawn to recover.
Usually, overwatering damage is mild and reversible if addressed promptly.
The same is mostly true for Zoysia lawns that have been cut too short (AKA “scalped”) or damaged due to dull mower blades.
Simply sharpen or switch out your mower blades, hold off on mowing for a month or two, and water and add fertilizer to allow it to recover gradually before mowing again normally.
For more information, head on over to our guide on cutting Zoysia grass.
Using a reel mower is highly recommended.
In the case of compacted soil, aeration will remedy the issue fairly quickly.
Zoysia develops very deep roots, making it hardy under heavy foot traffic yet uniquely susceptible to poorly aerated soil.
If your soil is too dense and compacted, the grass won’t pull enough nutrients and water up through its roots.
Finally, Zoysia needs plenty of sunlight!
If your thatch layer has become out of control, your lawn will begin to lose its rich, green color, as it won’t be able to access as much sunlight as it normally needs to thrive.
In the case of lawn fungi or lawn pests, you’ll need to treat any affected areas quickly with fungicides or pesticides.
Depending on how damaged your lawn is after the treatment, you’ll either be able to revive it with water and fertilizer alone or have to remove the affected patches entirely and reseed them.
Check out our picks for the best fertilizers for Zoysia grass.
How Often Do You Water Zoysia Grass?
Zoysia grass is very drought-tolerant and, as a result, requires a lot less moisture than most other lawn grasses. It only needs around 1” inches of water per week, which translates to about one watering per week during its growing season and one watering every two weeks during its dormant season.
Watering Zoysia grass is essential to its growth and healthy appearance, but watering the right amount is perhaps even more important to prevent overwatering damage or drought damage.
As we touched on earlier, drought tolerance does not mean Zoysia can go weeks or months with no water at all!
It simply means it needs less water than most other grasses and is uniquely susceptible to overwatering damage.
Overall, during the active growing season in spring and summer, you should aim to water your Zoysia grass weekly, ideally during the early morning hours before the air temperature is too hot.
This way, the water will reach the Zoysia grass’ deep roots before it has a chance to evaporate under the harsh mid-afternoon sunlight.
During Zoysia’s dormant season in the fall and winter, you’ll only need to water it every 10 to 14 days or so.
Regardless of the season, you’ll need to keep an eye on the weather forecast and how much rain you’re getting each week.
If your area has recently gotten some heavy rains, it’s likely fine to skip your normal watering session for the week.
In general, underwatering is better than overwatering for Zoysia grass.
However, finding the right balance will mostly depend on your soil quality and aeration and how much rain your lawn has gotten recently.
With properly aerated soil and no excess thatch layer, your lawn will be able to absorb water and nutrients much more efficiently.
Can Zoysia Grass Get Too Much Water?
Zoysia grass is extremely susceptible to overwatering. Too much water will leave your lawn especially prone to fungi and other pests, and it will interfere with your lawn’s growth rate and how well it can absorb nutrients and sunlight.
One of the most important factors for caring for Zoysia grass is watering it enough–but not too much.
Warm-season grasses, in general, typically require minimal water to thrive, usually in the range of ¾” to 1” inch per week.
You’ll be able to easily tell if you’re overwatering your Zoysia grass simply by paying attention to its appearance and how it reacts to your watering schedule.
If you notice standing water hours after you’ve watered your lawn, you’ve likely overwatered it.
Other signs include yellow or brown lawn patches where the grass has been overwatered or the presence of excess water runoff shortly after watering.
Zoysia has very deep roots, meaning it does best with infrequent yet deep waterings.
Start with watering once a week during growing season and once every two weeks during the dormant season, and then slightly adjust from there as needed.
How Do You Treat Brown Zoysia Grass?
Brown Zoysia grass has many causes, like overwatering and scalping, but brown patch fungus is the most common. You’ll need to treat the brown patch with a fungicide, which will take anywhere from a few weeks to several months to treat the affected areas. Reseeding will likely also be necessary.
If your Zoysia grass has turned brown, there are some potential underlying causes.
Overwatering, for example, will often turn patches of grass yellow or brown temporarily until the water either runs off or is gradually absorbed.
Mowing your lawn too short or with dull blades is also a common killer of Zoysia, as this leaves it very susceptible to further damage from diseases and lawn pests.
However, perhaps the most common cause of brown patches of Zoysia grass is the dreaded brown patch fungus.
This type of fungi looks exactly how it sounds–large, brown patches of grass that ultimately spread throughout your entire lawn if left untreated.
Overwatering and “scalping” your lawn will advance the damage even further.
Treating brown patch fungus requires using a powerful fungicide and plenty of TLC for your lawn in the following weeks.
The severity of the brown patch and how promptly you treat it will determine how well your lawn can bounce back from the disease.
Most lawn experts recommend using something like Grower’s Ally Fungicide as soon as you confirm the presence of the fungus to prevent it from spreading rapidly throughout your yard.
Unfortunately, if the lawn fungus has progressed past a certain point, your lawn won’t be able to bounce back as quickly.
In this case, you’ll likely need to remove the affected patches entirely and reseed them altogether.
This is why promptly treating lawn fungi and pests is crucial to prevent irreversible damage and keep your grass healthy.
How Do You Make Zoysia Grass Greener?
Making your Zoysia grass look green and healthy mostly comes down to proper lawn maintenance. This means you’ll need to water it consistently every week, mow it with sharp blades whenever it exceeds 2” inches or so, and use a high-quality 3-1-2 or 4-1-2 NPK fertilizer monthly during the growing season.
Zoysia is well-loved for its fairly low-maintenance nature, but this doesn’t mean it doesn’t require any maintenance at all!
Frequent (but not too frequent) waterings are necessary to keep your lawn hydrated, and you’ll also need to keep it trimmed to around 1.5” inches or so with sharp blades to prevent it from tearing or becoming damaged.
Using the right kind of fertilizer during your Zoysia lawn’s growing season is also highly effective at ensuring a lush, green lawn.
We recommend using something like The Andersons Professional PGF Complete 16-4-8 Fertilizer once a month during the spring and summer growing season to keep your soil full of the nutrients your lawn needs.
Finally, make sure your soil is aerated and dethatched regularly.
Zoysia has deep roots, so heavily compacted soil or a heavy thatch layer will prevent it from absorbing the water, nutrients, and sunlight it needs to look green and vibrant.
Is Zoysia Grass Hard to Maintain?
Zoysia grass is not particularly hard to maintain. However, it does have a few unique weaknesses you’ll need to keep in mind, particularly its inability to tolerate excess water and its need to be kept at a slightly taller height than most other grasses.
Zoysia grass has a reputation for being a fairly low-maintenance, shade tolerant, warm-season grass, and this is true–for the most part.
Low maintenance, of course, still means it needs some upkeep, mostly in the form of proper watering, mowing, and fertilizing schedule, as detailed above.
Zoysia is also uniquely susceptible to many lawn diseases and pests if it is overwatered or “scalped.”
Another thing to keep in mind is Zoysia’s deep roots.
This means you’ll need to aerate and dethatch slightly more often than you might need to for most other kinds of grass to ensure your lawn’s roots can absorb enough water, nutrients, and sunlight.
Maintaining only the soil surface is not enough!
By keeping your lawn properly watered, mowed, aerated, dethatched, and fed with the right kind of fertilizer, you’ll be able to easily keep your Zoysia lawn looking great year-round.
Check out our other post on Zoysia grass spreading information to learn more about maintaining and successfully growing Zoysia.