How to Kill Bermuda Grass Without Killing Other Grass

Selectively removing bermuda grass from a lawn while keeping the surrounding turf alive is one of the more frustrating challenges in lawn care, but it is genuinely possible with the right herbicide matched to the right desirable grass. The approach splits sharply depending on whether your lawn is a cool-season species like tall fescue or a warm-season one like zoysiagrass. For cool-season lawns, selective grassy-weed herbicides containing fluazifop or sethoxydim can target bermuda grass directly. For warm-season lawns, the options are narrower and the margin for error is thinner, but certain herbicide combinations still work. In either case, bermuda grass’s aggressive underground growth means a single application rarely finishes the job.

Why Bermuda Grass Fights Back So Hard

Before choosing a weapon, it helps to understand what you’re up against. Bermuda grass spreads through both stolons (runners along the surface) and rhizomes (runners underground), which makes it one of the most aggressively regenerating turf species in existence. A proteome study of bermuda grass stems confirmed that its ability to grow both above and below ground simultaneously gives it unusually fast clonal propagation and strong regeneration capacity.¹ Even a small fragment of rhizome left in the soil can resprout into a new plant. This is why simply pulling bermuda grass by hand or scalping it with a mower rarely works for long. The visible above-ground portion is only part of the plant; the network below the surface is extensive and resilient.

Bermuda grass also germinates readily from seed. Research on ten seeded bermuda grass cultivars found that seeds can germinate at average temperatures as low as about 15°C (roughly 59°F), meaning new plants can establish earlier in spring and later in fall than many homeowners expect.² So even after you kill an established stand, stray seeds in the soil can start the problem over again if conditions are right.

Selective Herbicides for Cool-Season Lawns

If your lawn is tall fescue, Kentucky bluegrass, perennial ryegrass, or a mix of these cool-season grasses, you have the most straightforward path. A class of herbicides known as ACCase inhibitors can kill bermuda grass while leaving cool-season turf largely unharmed. The most commonly available active ingredients in this class for homeowners are fluazifop-P-butyl (sold under brands like Fusilade II and Ornamec) and sethoxydim (sold as Segment or Vantage). Fenoxaprop is another option in this family but is less widely available to consumers.

These herbicides work by shutting down an enzyme that grasses need for producing fatty acids. Without new fatty acids, the plant can’t build cell membranes or grow new tissue. The herbicide is absorbed through the leaves, then moves through the plant’s vascular system to actively growing points, where it stops new leaf production and eventually kills the meristematic tissue.³ Death isn’t instant. You’ll typically see the bermuda grass stop growing within a week, start yellowing within two weeks, and die back over three to four weeks.

The reason these herbicides spare cool-season lawns is biological. Different grass species metabolize these chemicals at different rates. Cool-season grasses like tall fescue break down fluazifop and sethoxydim quickly enough that the herbicide never reaches toxic concentrations in the plant. Bermuda grass metabolizes them more slowly, so the active ingredient accumulates and does its damage. This selectivity isn’t absolute, though. Applying at too high a rate, in hot weather, or to a stressed lawn can still cause temporary yellowing in your desirable turf.

How to Apply for Best Results in Cool-Season Turf

Timing matters more than most product labels convey. Bermuda grass is a warm-season species that grows most actively when soil temperatures are above about 18°C (65°F), typically from late spring through early fall. You want to spray when bermuda grass is growing vigorously, because the herbicide needs to be taken up through actively photosynthesizing leaves and translocated to growing points. Spraying dormant or semi-dormant bermuda grass wastes your effort.

The practical window in most of the transition zone and southern cool-season regions is roughly late May through August. Plan on at least two applications spaced four to six weeks apart. The first pass kills the above-ground growth and damages much of the root system. But those deep rhizomes often survive and push out new shoots, which is where the second and sometimes third application finishes the job. Skipping the follow-up applications is the single most common reason people fail at this project.

A few tips that make a real difference:

• Don’t mow first: You want plenty of leaf surface to absorb the herbicide. Let the bermuda grass grow for at least a week before spraying, and don’t mow for several days after.
• Water the lawn beforehand: A well-hydrated bermuda grass plant translocates herbicide more effectively than a drought-stressed one.
• Spray in the morning: Avoid the heat of midday, which can cause the spray to evaporate before absorption. Early morning or late afternoon works well.
• Use a surfactant: Adding a non-ionic surfactant helps the spray stick to bermuda grass’s waxy leaves, improving uptake.

Removing Bermuda Grass from Zoysiagrass

This is where things get trickier. Zoysiagrass is a warm-season grass, just like bermuda grass, so the metabolic differences that protect cool-season grasses don’t fully apply here. You can’t simply spray fluazifop on a zoysia lawn at the standard bermuda-killing rate without risking damage to the zoysia itself.

However, research has found a workaround. Adding triclopyr (a broadleaf herbicide) to fluazifop or fenoxaprop acts as a safener for zoysiagrass. A study specifically testing this combination confirmed that triclopyr reduced the injury fluazifop and fenoxaprop caused to zoysiagrass turf without decreasing bermuda grass suppression. In fact, fenoxaprop combined with triclopyr actually improved bermuda grass suppression compared to fenoxaprop alone.⁴ Additional research confirmed this safening effect and found that for relatively tolerant zoysia cultivars, the triclopyr combination might even allow higher-than-labeled fluazifop rates with little negative impact on turf quality.⁵

This means if you have a zoysiagrass lawn, a tank mix of fluazifop (or fenoxaprop) plus triclopyr is your best chemical option. The timing recommendations are similar to those for cool-season lawns: apply when bermuda grass is actively growing, expect to make multiple applications, and don’t mow right before or after spraying.

One caveat: not all zoysiagrass cultivars respond equally. Some newer cultivars show greater tolerance to fluazifop than older varieties. If you’re unsure, treat a small test area first and wait two weeks to assess damage before treating the entire lawn.

What About Other Warm-Season Grasses?

If your lawn is St. Augustinegrass, centipedegrass, or buffalograss, the options for selective bermuda grass removal are extremely limited. These grasses are also susceptible to ACCase-inhibiting herbicides, and there’s no reliable safener combination for them the way triclopyr works for zoysiagrass. For these lawns, you’re largely stuck with two unsatisfying choices: spot-treat bermuda grass patches with a non-selective herbicide like glyphosate and reseed or re-sod the bare areas, or pursue long-term cultural suppression.

Some newer herbicide classes are being investigated for selective use in warm-season turf. HPPD-inhibiting herbicides like topramezone, mesotrione, and tembotrione show different injury levels on different turf species. Research comparing these herbicides found that the amount of injury they cause varies considerably across species: bermuda grass showed moderate susceptibility to topramezone but less response to mesotrione, while zoysiagrass was actually more sensitive to topramezone than bermuda grass was.⁶ This means these chemicals currently don’t offer a clean way to kill bermuda grass selectively in most warm-season lawns. The research is ongoing, and label changes could expand options in the future, but right now the zoysia-plus-triclopyr approach remains the standout option for warm-season selectivity.

Using Shade and Competition as Long-Term Weapons

Bermuda grass is famously sun-hungry. It performs poorly in shade, and that weakness can be exploited as part of a suppression strategy. Research on bermuda grass under shade conditions found that higher mowing heights improved the plant’s shade response, meaning bermuda grass at typical lawn-mowing heights fares even worse in low-light conditions than bermuda grass allowed to grow tall.⁷ The practical implication is that if parts of your lawn sit under tree canopy or structures, bermuda grass will naturally struggle there. You can enhance this by planting shade-tolerant grasses like fine fescue or St. Augustinegrass in those areas, which will outcompete weakened bermuda grass over time.

Canopy cover from your desirable grass also matters in the open sun. A study on turf competition showed that dense canopy cover from existing turf was a stronger factor in suppressing weed establishment than soil conditions like compaction.⁸ The lesson applies in reverse too: maintaining a thick, healthy stand of your desired grass gives bermuda grass fewer openings to reinvade after you’ve treated it. Overseeding bare spots promptly, fertilizing to encourage your lawn’s density, and mowing at the right height for your species all contribute to keeping bermuda grass from creeping back in.

The Solarization Option

For smaller areas or badly infested patches where you’re willing to sacrifice everything and start over, soil solarization offers a non-chemical approach. The method involves mowing the area as low as possible, watering deeply, then covering the area with clear plastic sheeting and sealing the edges. Over four to eight weeks of summer sun, the trapped heat can raise soil temperatures high enough to kill bermuda grass rhizomes and seeds in the top several inches of soil. This works best in hot climates with strong sun exposure and isn’t selective in any way, so it kills everything under the plastic. You’ll need to reseed or resod after removing the plastic. It’s a scorched-earth approach, but for patches where bermuda grass is so entangled with your desirable grass that selective herbicide applications would be impractical, starting fresh sometimes makes the most sense.

Why One Application Almost Never Works

The biggest misconception about killing bermuda grass is expecting one round of herbicide to finish the job. Bermuda grass rhizomes can extend a foot or more below the surface, and herbicide doesn’t always reach the deepest nodes. Those surviving rhizome fragments have enough stored energy to push out new growth within weeks. The germination research mentioned earlier also means that bermuda grass seeds sitting in the soil can germinate at relatively low temperatures, repopulating treated areas well into fall.²

A realistic timeline for removing bermuda grass from a cool-season lawn looks something like this: two to three herbicide applications spaced four to six weeks apart during the first summer, followed by monitoring the next spring and spot-treating any regrowth. Many people find that a few scattered bermuda grass plants pop up the following year from deep rhizome pieces or seeds, and these need a quick follow-up spray. Declaring victory after a single growing season is premature.

For zoysiagrass lawns, the timeline is similar, though the lower herbicide rates needed to protect the zoysia sometimes mean slower bermuda grass decline and possibly an extra application cycle. Patience matters here. Zoysia recovers relatively well from the transient injury these herbicides cause, and each successive treatment weakens the bermuda grass further while the zoysia fills in the gaps.

Bermuda Grass Creeping in from Neighbors

Even a perfectly executed treatment program can fail if bermuda grass is growing in an adjacent lawn, road shoulder, or unmaintained strip. Stolons can cross property boundaries surprisingly fast, and rhizomes can extend under edging and hardscape. If this is your situation, you have a few options beyond repeat spraying. Physical root barriers buried at least six inches deep along the property line can slow underground spread. Maintaining a well-edged border where you mow and treat the edge strip regularly catches stolons before they get established. And keeping your desirable lawn thick and competitive along that border makes it harder for bermuda grass runners to gain a foothold.

Some people install a strip of landscape fabric or a paved border between their lawn and the bermuda grass source, which can help but is rarely perfect. Bermuda grass will eventually grow over or around any barrier that isn’t maintained. The honest reality is that if you share a boundary with a bermuda grass source, you’re managing a chronic condition rather than achieving a one-time cure. An annual spot-treatment in early summer along the border often becomes part of the routine.

Pre-Emergent Herbicides and Bermuda Grass Seeds

If your bermuda grass problem includes new plants sprouting from seed each year, a pre-emergent herbicide applied in spring can help break the cycle. Products containing prodiamine or dithiopyr prevent bermuda grass seeds from germinating, though they won’t affect existing plants that spread by stolons and rhizomes. Timing the pre-emergent to soil temperatures just before bermuda grass germination begins is important. Since bermuda grass can germinate at lower temperatures than commonly assumed, erring on the earlier side is wise in the transition zone.

Keep in mind that pre-emergent herbicides also prevent your desirable grass seed from germinating, so if you’re planning to overseed bare patches, you’ll need to wait until the pre-emergent barrier has broken down, typically 8 to 12 weeks depending on the product. This creates a scheduling puzzle: treat bermuda grass with post-emergent herbicide in early summer, apply pre-emergent to catch seeds, then overseed in fall once the pre-emergent has worn off. It requires planning, but this layered approach addresses bermuda grass on all three fronts: existing plants, vegetative spread, and seed germination.

Herbicide Resistance and What to Watch For

ACCase-inhibiting herbicides, the class that includes fluazifop and sethoxydim, face a growing resistance problem in agricultural weeds. The same enzyme-targeting mechanism that makes them effective also creates strong selection pressure for resistant biotypes.³ While herbicide-resistant bermuda grass in residential lawns hasn’t been widely documented the way resistant agricultural weeds have, the biology suggests it’s possible, especially with repeated use of the same active ingredient over many years.

If you notice that bermuda grass in a treated area isn’t responding to fluazifop the way it used to, rotating to a different active ingredient within the same class (switching from fluazifop to sethoxydim, for instance) or using a different mode of action for a season can help. This is more of a concern for professionals managing large areas than for homeowners tackling a backyard patch, but it’s worth knowing that the tool can dull over time if overused.