How to Kill Weeds in Zoysiagrass Without Damaging Turf

There’s nothing more frustrating than watching weeds creep into your Zoysia lawn after all the effort you’ve put into keeping it looking beautiful. But here’s the good news: you can knock out weeds and protect that beautiful turf with the right approach.

Controlling weeds in Zoysiagrass is all about timing, using the right products, and keeping your turf strong. With the right mix of pre-emergents, such as Prodiamine 0-0-7, and post-emergents, such as Certainty and Celsius® WG, plus a solid maintenance plan, you’ll be well on your way to a weed-free, golf course-worthy lawn.

This guide breaks down how to kill weeds in Zoysiagrass safely, what products to use (and avoid), and how to keep your turf looking like a fairway all season long.

Weed Growth in Zoysiagrass Lawns

Zoysiagrass is like the bodybuilder of warm-season grasses — thick, strong, and great at flexing against intruders. Its dense growth habit naturally helps crowd out many weeds. But even this turf titan has its weaknesses. When your lawn gets stressed or neglected, opportunistic weeds like crabgrass and spurge rush in like uninvited guests at a backyard BBQ.

Here are some of the biggest reasons weeds sneak into your Zoysia lawn:

🕒 Infrequent Mowing

Letting your Zoysiagrass grow too tall and then cutting it back drastically is another stressor. This yo-yo approach weakens the turf and makes recovery slower, giving weeds the upper hand. Stick to the one-third rule: never remove more than one-third of the grass height in a single mow.

🪨 Compacted or Nutrient-Poor Soil

Zoysia has deep roots but needs healthy, well-aerated soil to thrive. When the ground is hard and compacted, roots struggle to grow, limiting water and nutrient uptake. If your lawn's color is off or growth is sluggish, it could be time for a soil test, aeration, and the right fertilizer to bring things back in balance.

💧 Inconsistent Watering and Fertilizing

Zoysia is drought-tolerant but still appreciates a consistent watering schedule, especially during hot summer months. Skipping or applying water erratically can lead to dry patches, making room for drought-loving weeds. The same goes for fertilization: too little and your lawn struggles; too much and you might accidentally feed the weeds instead.

Bottom line? A healthy Zoysia lawn is your first and best defense against weeds. When your grass is thick, green, and thriving, there's simply no room for weeds to settle in. But when stress shows up, weeds see an opportunity, and they don’t need an invitation.

Pre-Emergent Weed Control for Zoysiagrass

If you only do one thing for weed control during the growing season, apply pre-emergent. Why? Pre-emergent herbicides work by stopping weed seeds from germinating, so the problem gets handled before it even begins.

Zoysiagrass plays well with the right pre-emergents. Use the right products at the right time, and you’ll dramatically reduce the number of weeds you have to see, pull, or spray.

🧪 Our Go-To Pre-Emergent Products for Zoysia Lawns

✅ Prodiamine 0-0-7 with Fertilizer

This one’s a staple in my lawn care program. It combines a powerful pre-emergent herbicide with a fertilizer, giving your Zoysiagrass what it needs to stay healthy without overfeeding. Prodiamine offers long-lasting protection and is perfect for both spring and fall applications.

• Best for: Crabgrass, goosegrass, Poa annua prevention
  

• Bonus: Safe for established Zoysia lawns
  

• Timing: Early spring and early fall

prodiamine-38-pre-emergent-herbicide-with-fertilizer-0-0-7-50lb

✅ Dimension 0-0-7 Pre-Emergent

Dimension is another winner, and it has a unique edge — it offers early post-emergent control, too. So, if you’re a little late with your spring application and a few weeds have already sprouted, Dimension can still knock them back while preventing new ones.

• Best for: Crabgrass, annual bluegrass, and other broadleaf weeds
  

• Bonus: Flexible timing thanks to early post-emergent activity
  

• Timing: Spring and early fall.

dimension-15-pre-emergent-herbicide-with-fertilizer-0-0-7

Both of these are selective herbicides for Zoysiagrass lawns, meaning they’re designed to target weeds while leaving your turf unharmed. Just follow the label directions, and you’re golden.

⏰ When to Apply Pre-Emergent to Zoysiagrass

Timing is everything with pre-emergents. Miss the window, and you’re playing catch-up all season long. Here's how to get it right:

• 🌱 Spring Application:
  Apply before soil temperatures reach 55°F — that’s usually between late February and March, depending on your region. This catches weeds like crabgrass before they germinate.
  

• 🍂 Fall Application:
  Hit your lawn with another round in early September before winter weeds like Poa annua and chickweed start sprouting. This is a major step in year-round weed control for Zoysiagrass.

Want to make timing even easier? Use a soil thermometer (they're cheap and super helpful), or check soil temps using online tools like GreenCast.

💡 Application Tips

• Use a broadcast spreader to apply evenly across your lawn.
  

• Water it in right after application (about ½ inch of irrigation) to activate the herbicide barrier.
  

• Avoid disturbing the soil too much afterward — raking or aerating can break the barrier and reduce effectiveness.

Pro Tip: Pre-emergents won’t kill fully-fledged existing weeds, so don’t skip this step, thinking your post-emergent will cover everything. Prevention is way easier (and cheaper) than cure.

Post-Emergent Weed Control for Zoysiagrass

Even if you’re on point with pre-emergents, some weeds will find a way in — especially if your Zoysia’s been stressed by heat, drought, or mowing mishaps. That’s where post-emergent herbicides come into play.

Post-emergents work on weeds that are already growing, so if you’re walking your lawn and spotting trouble like sedges, spurge, or broadleaf invaders, don’t panic. You’ve still got options that will knock them out without harming your Zoysiagrass.

The key here is selectivity. You want to use products that target the weeds but leave your turf unharmed. Zoysia can be sensitive to certain herbicides, so it’s critical to stick with safe and proven ones.

🌿 Our Go-To Post-Emergent Kits for Zoysiagrass Lawns

✅ Celsius and Certainty Herbicide Kit

This dynamic duo is one of the best all-around options for weed control in Zoysiagrass. It tackles everything from grassy weeds like goosegrass and dallisgrass to broadleaf troublemakers like spurge, clover, and dandelion.

• Celsius: Great for broadleaf and some grassy weeds; safe for warm-season lawns.

• Certainty: Excellent for sedges and hard-to-kill grassy weeds like Poa annua.
  

• Perfect for: Mid-to-late spring and early summer when weeds are actively growing.

This combo is safe for Zoysia when used according to label directions, and it’s highly effective without causing turf damage.

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✅ Recognition and Fusilade II Herbicide Kit

Got Bermudagrass invading your Zoysiagrass? You’re not alone, and this kit is the solution.

Bermuda might be a great grass in the right context, but when it starts creeping into your carefully maintained Zoysia lawn, it becomes a major nuisance. That’s where the Recognition and Fusilade II Kit shines.

• Recognition Herbicide: A selective herbicide that includes the proprietary safener, metcamifen, making it possible to remove Bermudagrass from Zoysia, St. Augustine, and Kikuyugrass. It allows you to use Fusilade II at higher rates without causing injury.
  

• Fusilade II: Targets and kills Bermudagrass while leaving your Zoysia alone.
  

• Ideal for: Suppressing and eliminating Bermuda in Zoysia or St. Augustine lawns.
  

• Pro tip: Multiple applications are usually needed for full control, so stay consistent.

This kit is a game-changer if your lawn has a Bermuda problem. Without it, Bermudagrass can outcompete your Zoysia over time and take over entire patches.

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Related: How to Get Rid of Bermudagrass In Your Zoysia or St. Augustine Lawn 

🧴 Application Tips for Safe and Effective Post-Emergent Use

1. 🎯 Spot Treat Whenever Possible
    Don’t blanket spray your entire lawn unless you’re dealing with widespread infestations. Focus on the problem areas to minimize turf stress and reduce herbicide use.
   

2. 🌡️ Apply When Temperatures Are Between 65–85°F
    This is the sweet spot when weeds are actively growing, and herbicides are most effective. Avoid spraying during extreme heat or cold, as it reduces effectiveness and increases the risk of turf injury.
   

3. 🧼 Use a Non-Ionic Surfactant
   Many post-emergents require a surfactant to help the product stick to the leaves and penetrate the waxy cuticle. Without it, coverage suffers, and results can be spotty. All our herbicide kits come with a surfactant and blue marker dye so you can see where you have applied.
   

4. 💧 Don’t Mow Immediately Before or After Application
    Let the weed have as much leaf surface as possible when spraying. Wait at least 2–3 days after mowing and hold off mowing again for another few days post-application.
   

5. 🚫 Don’t Overdo It
   Always follow the label rates. More isn’t better — too much product can harm your lawn and lead to resistance over time.

Related: 10 Common Mistakes to Avoid When Using Weed Killers 

Safest and Best Herbicide Options for Zoysiagrass

Not all weed killers are created equal. Use the wrong one, and you’ll damage your turf.

Here’s what to look for in a safe herbicide for Zoysiagrass:

• Clearly labeled for use on warm-season grasses

• Active ingredients like Dicamba, Sulfosulfuron, or 2,4-D

• Avoid non-selective killers (like RoundUp) unless you’re doing a full renovation and intend to kill your whole lawn off.

Pro Tip: Always read the label and do a small test patch if you’re trying a new product.

Here’s a cheat sheet of top-performing, Zoysia-safe products:

🧩 Weed Control Zoysiagrass Lawns

Weed Type	Recommended Product	Why It Works
Crabgrass	Prodiamine 0-0-7 or Dimension 0-0-7 Quinclorac 75 DF	Pre-emergents that prevent crabgrass before it sprouts Post-emergent crabgrass killer safe for Zoysiagrass
Annual Bluegrass (Poa Annua)	Specticle FLO (fall) or Certainty Herbicide	Stops Poa before it emerges; Certainty kills it post-emergence
Spurge, Clover, Dandelion	Celsius + Certainty Herbicide Kit	Targets a wide range of broadleaf weeds safely in Zoysiagrass
Nutsedge (Yellow or Purple)	Certainty or SedgeHammer®	Selectively controls sedges without harming Zoysia
Johnsongrass, Dallisgrass (suppression)	Celsius + Certainty Herbicide Kit	Great for hard-to-control grassy and broadleaf weeds
Bermudagrass (Invasive in Zoysia)	Recognition + Fusilade II Herbicide Kit (N.B. Fusilade II should not be used on Zoysia without Recognition.)	Suppresses and kills Bermuda in Zoysiagrass lawns
Mixed Weeds	Celsius + Certainty Kit (broad control)	Covers most grassy and broadleaf weeds found in warm-season lawns

 

Related: The Best Crabgrass Weed Killers That Won’t Kill Your Turfgrass 

Zoysiagrass Maintenance and Weed Prevention

The best weed control? A thick, healthy lawn. This naturally suppresses weeds by shading the soil and outcompeting unwanted invaders.

Here’s how to build weed resistance into your Zoysia care routine:

✂️ Mowing: 

• Keep it at 1–2 inches, depending on your mowing equipment. If you’re using a reel mower, you can go shorter (.50 to 1 inch). Rotary mower users should aim for the 1.5–2-inch range.

• Stick to the one-third rule: never remove more than one-third of the blade height in a single mow.

💧 Watering: 

• Zoysia thrives with 1 inch of water per week, whether from rainfall or irrigation.
  Water deeply and infrequently to encourage deeper roots, which helps the lawn withstand drought.

• Water in the early morning to reduce evaporation and minimize disease risk.

🌿 Fertilization:

• During the growing season (late spring through summer), feed your lawn with a slow-release, nitrogen-rich fertilizer like Lebanon Complete 14-7-14.

• Avoid fertilizing too early in spring; wait until the grass is actively growing and greening up.

🌬️ Aeration: 

• Core aeration once a year is one of the best things you can do for soil health.

• It relieves compaction, improves nutrient and water flow, and helps your Zoysia roots grow deeper and stronger.

• Best time? Late spring to early summer, when Zoysia is in active growth.

Summer Lawn Care for Zoysia Grass

Summer can be tough on any lawn, and Zoysiagrass is no exception. Heat, foot traffic, and inconsistent watering stress your turf, and stressed lawns are prime real estate for weeds.

Here’s how to keep your lawn looking its best when the heat cranks up:

• Raise your mowing height slightly. Taller grass blades provide more shade to the soil, which helps reduce moisture loss and discourages weed seeds from sprouting.
  

• Keep your mower blades sharp. Dull blades tear the grass instead of cutting it cleanly, leading to jagged edges, moisture loss, and more disease pressure.
  

• Spot-treat weeds as soon as you see them. Catching and treating weeds early prevents them from going to seed and spreading across your lawn.
  

• Stay consistent. Most lawn problems start when maintenance slips. Regular mowing, watering, and feeding go a long way in keeping Zoysia strong and weed-resistant.

FAQs: Weed Control in Zoysiagrass Lawns

Q: Can I use vinegar or boiling water to kill weeds in Zoysia?

A: It’s best not to. Those are non-selective and will damage your grass. These DIY methods might seem natural or harmless, but they can leave unsightly dead patches in your lawn and set back healthy turf growth.

Q: Will weed killers discolor my lawn?

A: Sometimes, but mainly if they’re misused. Discoloration can happen if you apply too much product, spray during extreme heat or drought, or use herbicide not labeled for Zoysiagrass. Even safe, selective herbicides can cause temporary yellowing if your lawn is already stressed. To avoid issues, always follow the label rates, apply during the recommended temperature range (usually 65–85°F), and make sure your lawn is well-watered and healthy going into treatment. If you're ever unsure, spot-test a small area first.

Q: Can I overseed Zoysia to help fight weeds?

A: Overseeding Zoysia is generally not recommended. It’s a slow-growing, warm-season grass that spreads by stolons and rhizomes, not seed. Instead, focus on improving turf density through fertilization, mowing, and aeration to naturally suppress weeds.

Q: What’s the best time of year to kill Bermudagrass in Zoysia?

A: The best time to target Bermudagrass is during the summer when it’s actively growing. Use the Recognition and Fusilade II Herbicide Kit and plan for multiple applications spaced a few weeks apart for best results.

Q: Will pulling weeds by hand damage my Zoysiagrass lawn?

A: Occasional hand-pulling is fine, especially for isolated weeds. Just be careful not to disturb too much soil, which can encourage more weed seeds to germinate. For widespread infestations, selective herbicides are more effective.

Q: How soon can I mow after applying post-emergent herbicide?

A: Wait at least 2–3 days after applying post-emergent herbicides before mowing. This gives the product time to be fully absorbed by the weeds for maximum effectiveness.

The Best Defense for Zoysia

The secret to weed-free Zoysiagrass isn’t just about what you spray; it’s about what you build. A healthy, dense lawn is your best long-term defense, and with the right maintenance and selective weed killers, you can keep unwanted invaders out without stressing your turf. Whether you’re blocking them before they sprout or cleaning up stragglers with precision herbicides, the tools are out there, and they work.

Check out our complete line of pre- and post-emergent herbicides, each one hand-picked for performance and safety on warm-season lawns like Zoysia. For more tips and tricks, visit our YouTube channel.