The best weed killers for zoysia grass are selective herbicides that target weeds without harming the turf. For broadleaf weeds like dandelions and dollarweed, a “three-way” herbicide containing 2,4-D, dicamba, and mecoprop is the go-to choice. For grassy weeds like crabgrass, quinclorac is one of the most effective options labeled specifically for zoysia. The key is matching the right product to the type of weed you’re dealing with and applying it at the right time of year.
Best Options for Broadleaf Weeds
Broadleaf weeds, the ones with wide, flat leaves like clover, dandelions, chickweed, and dollarweed, are the most common invaders in zoysia lawns. The standard treatment is a three-way broadleaf herbicide that combines 2,4-D, dicamba, and mecoprop (sometimes listed as MCPP on the label). These three active ingredients work together to kill a wide range of broadleaf weeds while leaving zoysia unharmed. SpeedZone Broadleaf Herbicide is one popular product in this category.
All three of those active ingredients individually carry a “tolerant” rating for zoysia at labeled rates, according to LSU AgCenter turf research. That means you can apply them with confidence as long as you follow the directions on the product label. Other broadleaf-safe options for zoysia include carfentrazone, halosulfuron (particularly effective against sedges and nutsedge), metsulfuron, and sulfentrazone.
Best Options for Grassy Weeds
Grassy weeds like crabgrass, goosegrass, and torpedograss are trickier because they’re biologically similar to your zoysia. That limits your choices, but a few herbicides thread the needle well. Quinclorac (sold as Drive 75 DF or Drive XLR8) is labeled for use on both bermuda and zoysia grass and is one of the most effective post-emergent crabgrass killers available. It should not be used on centipede, St. Augustine, or bahiagrass, but zoysia handles it well.
Fenoxaprop is another post-emergent option rated as tolerant for zoysia. It targets grassy weeds that have already sprouted without damaging the turf. For torpedograss specifically, quinclorac may need up to three applications at the labeled rate to get the job done.
Stopping Weeds Before They Sprout
The most effective weed control strategy for zoysia is preventing weeds from ever emerging. Pre-emergent herbicides create a chemical barrier in the soil that kills weed seedlings as they germinate. Prodiamine is one of the most widely used pre-emergent active ingredients for warm-season grasses, and it’s safe for zoysia. A combination product containing sulfentrazone and prodiamine can handle both pre-emergent weed prevention and some post-emergent control of existing weeds. This combination is safe for zoysia after the second mowing of the season.
Timing matters more than product choice with pre-emergents. NC State Extension recommends applying pre-emergent herbicides to zoysia lawns from mid-February to early March, before soil temperatures consistently reach the point where crabgrass and other summer annuals begin germinating. If you miss that window, the seeds will have already sprouted and a pre-emergent won’t help.
What to Avoid on Zoysia
Non-selective herbicides like glyphosate (the active ingredient in Roundup) will kill zoysia along with everything else. A common misconception is that you can spray glyphosate on zoysia during winter dormancy to clean up cool-season weeds. The University of Arkansas Extension is clear on this: do not apply glyphosate to dormant zoysia. Even though zoysia turns completely straw-colored in winter and looks dead, it retains green tissue near the soil line. Glyphosate can damage or kill that living tissue. Bermudagrass is the only lawn grass that can tolerate glyphosate during full dormancy.
MSMA is another herbicide to approach carefully. It carries a “tolerant to intermediate” safety rating on zoysia, meaning it can cause some injury depending on conditions. If you have other options available, they’re generally safer choices.
Application Timing and Temperature
When you apply a weed killer matters almost as much as which one you choose. Post-emergent broadleaf herbicides work best when weeds are actively growing, typically in spring and fall for cool-season weeds, and late spring through summer for warm-season weeds. Apply when the weeds are young and small for the best results.
Temperature is a critical factor that many homeowners overlook. When air temperatures exceed 80 to 85°F, most post-emergent broadleaf herbicides can injure your zoysia turf regardless of the product’s formulation. On hot days, the herbicide becomes more volatile and the grass is under more stress, creating a recipe for turf damage. If you’re dealing with summer weeds in a zoysia lawn, apply early in the morning when temperatures are still below that threshold and the day isn’t expected to climb past 85°F.
Adding a nonionic surfactant (sometimes called a spreader-sticker) to your spray solution can improve results. Surfactants help the herbicide spread evenly across weed leaves and stick to the foliage instead of beading up and rolling off. Some products already contain a surfactant, so check the label before adding more. Oklahoma State University Extension notes that surfactants labeled for use with herbicides generally improve how well the solution coats and adheres to foliage.
Matching the Herbicide to Your Weed Problem
Identifying your weed before buying a product saves money and prevents unnecessary chemical applications. Here’s a quick guide to the most common zoysia lawn invaders:
- Crabgrass: Prodiamine as a pre-emergent in late winter. Quinclorac as a post-emergent if it’s already growing.
- Dollarweed: A three-way broadleaf herbicide with 2,4-D, dicamba, and mecoprop. Atrazine works too, but is more commonly used on St. Augustine and centipede lawns.
- Nutsedge: Halosulfuron is one of the most effective options and is rated tolerant for zoysia.
- Clover, dandelions, and other common broadleafs: Any three-way broadleaf herbicide will handle these reliably.
- Winter annual weeds (henbit, chickweed): A fall-applied pre-emergent prevents them. Post-emergent broadleaf herbicides will kill them if they’ve already appeared.
For lawns with multiple weed types, a combination approach works best: a pre-emergent application in late February or early March to prevent summer annuals, followed by spot treatments with a selective post-emergent herbicide as needed throughout the growing season. Healthy, thick zoysia is naturally competitive against weeds, so proper mowing height, fertilization, and watering reduce how much herbicide you’ll need over time.