Weed Control
Best Weed Killer for Zoysia: Tolerance Is Not the Problem
Zoysia takes almost everything the other Southern grasses cannot. Its real limits are temperature, mowing gap and growth — and it recovers slowly when you miss them.
Selective Grass Herbicide (fluazifop, spot treatment)
Gordon's Ornamec 170 Grass Herbicide, 32 oz Review
★★★★★ 4.5/5
our editor rating how we score4.2/5 from 1,230 shoppers at Amazon — their number, not ours.
$38–$45
Typical price · 32 oz concentrate; 2 fl oz per gallon treats 1,000 sq ft of tall fescue
Affiliate links — see our disclosure. Commissions never influence verdicts.
The tank-mix partner Virginia Tech's bermudagrass programme calls for — and its own label carries a dedicated 'Bermudagrass Control in Tall Fescue' section with rates.
Our Verdict
This is the product that closes the gap in every bermudagrass-in-fescue article, including ours until now. Its label (EPA Reg. 2217-751) is not a general grass killer with a turf disclaimer bolted on — it has a section headed 'Bermudagrass Control in Tall Fescue' with its own rate, its own timing and its own honest expectation. The rate is 2 fl oz per gallon to treat 1,000 square feet by hand sprayer, applied in spring and fall after green-up, repeated at 14 to 21 day intervals if regrowth occurs. And the sentence that should set your expectations is on the label rather than in a review: complete control may take 1 to 2 growing seasons. Read three restrictions before buying. The label says do not apply to tall fescue turf unless injury can be tolerated — some discoloration is part of the deal. It tells you to take care in July and August and to avoid drought-stressed turf. And the bermudagrass sections carry a footnote reading not applicable in California, so this use is excluded there.
✅ Pros
- Label has a dedicated 'Bermudagrass Control in Tall Fescue' section with rate and interval, which almost nothing on a consumer shelf does
- 1.70% is a homeowner-scale concentration — the professional equivalent is 24.5%, where a measuring error matters far more
- Separate zoysiagrass section at a lower rate (1.3 fl oz per gallon) for the same problem in warm-season turf
- The label sets a realistic expectation itself: complete control may take 1 to 2 growing seasons
⚠️ Cons
- Label states do not apply to tall fescue turf unless injury can be tolerated — temporary discoloration is expected
- Bermudagrass uses are marked not applicable in California
- Take care with July and August applications, and avoid drought- or heat-stressed turf
- Suppression rather than eradication, and it only works if the fescue is mown tall — see the linked guide
Product type
Selective Grass Herbicide (fluazifop, spot treatment)
Active ingredient
Fluazifop-P-butyl 1.70%
Price range
$38–$45
Coverage
32 oz concentrate; 2 fl oz per gallon treats 1,000 sq ft of tall fescue
Best for
Suppressing bermudagrass in a tall fescue lawn, tank mixed with a turf-labelled triclopyr
our editor rating
4.5 out of 5
Where our facts come from
Label read on the registrant's own PDF
EPA Reg. No. 2217-751
We read the printed label published by the company that holds the registration. EPA hosts no PDF for this one, so this is the best available text.
What we found when we read it
Full label read 2026-08-03 (PBI/Gordon's own label PDF). EPA Reg. 2217-751, fluazifop-P-butyl 1.70%. Section 3.2 'Bermudagrass Control in Tall Fescue': spring and fall after green-up, care in July/August, repeat at 14 to 21 day intervals if regrowth occurs, 2 fl oz per gallon per 1,000 sq ft, and 'Complete control may take 1 to 2 growing seasons.' Section 3.1 covers zoysiagrass at 1.3 fl oz per gallon from about June 1 at 30-day intervals. Blanket caution: 'Do not apply to tall fescue turf unless injury can be tolerated.' STATE RESTRICTION: both bermudagrass sections carry the footnote '*Not applicable in California'. Note the stronger sibling product, plain ORNAMEC, is a separate registration (2217-728) — match the number, not the brand.
Where this page and the container disagree, the container wins — the label is the legal authority on rates and restrictions. How to read one yourself.
Where This Product Matters
Matched against each state's actual disease, weed and pest pressure.
Alabama
Alabama hub →Crabgrass
🌾 Zoysia🌾 Tall Fescue
Application window: April–May and September, and check every label against centipede before it leaves the shelf
Arizona
Arizona hub →CrabgrassBermudagrass mites
🌾 Zoysia
Application window: March–May and during monsoon flushes; Celsius-type products handle 100°F+ windows
Arkansas
Arkansas hub →Crabgrass
🌾 Zoysia🌾 Tall Fescue
Application window: Bounded by the label's temperature ceiling rather than the calendar — spring treatments finish before the June heat arrives, and nothing selective goes down again until September cools off
California
California hub →CrabgrassCommon bermudagrass invading fescue lawns
🌾 Tall Fescue🌾 Zoysia
Application window: March–May while weeds are young; avoid spraying drought-stressed turf in summer
⚖️ The bermudagrass-in-turf uses on this label are footnoted 'Not applicable in California', so the reason most people buy it is excluded here. Its other labelled grass-weed uses are unaffected — check the section you intend to use before buying.
Colorado
Colorado hub →Crabgrass
Application window: May–June and September; high-altitude sun makes stressed turf easy to injure, so spot-treat rather than blanket-spray
Connecticut
Connecticut hub →Crabgrass
🌾 Tall Fescue
Application window: Broadleaf sprays in May–June and again in September, when the weeds are moving sugars to the roots; skip July and August, when a stressed cool-season lawn takes the injury and the weed does not
Delaware
Delaware hub →Crabgrass
🌾 Tall Fescue🌾 Zoysia
Application window: April to late May, then September into October. Skip July and August entirely: this is the transition zone, and a stressed tall fescue lawn takes the injury the weed shrugs off
Florida
Florida hub →Crabgrass
🌾 Zoysia
Application window: March–May and October–November; avoid applications above 85°F
Georgia
Georgia hub →Crabgrass
🌾 Zoysia🌾 Tall Fescue
Application window: April to early June and September–October; avoid mid-summer sprays on stressed turf
Hawaii
Hawaii hub →Crabgrass
🌾 Zoysia
Application window: Year-round where the turf is actively growing, which is most of the time; the constraint is heat and drought stress on the leeward side rather than a dormant season
Idaho
Idaho hub →Crabgrass in the warmer southern valleys
🌾 Tall Fescue
Application window: Late April into June, then September into October; skip the July and early August heat, which is also when UI's own fertilizer schedule goes quiet
Illinois
Illinois hub →Crabgrass
🌾 Tall Fescue🌾 Zoysia
Application window: May–June and September; fall beats creeping charlie best
Indiana
Indiana hub →Crabgrass
🌾 Zoysia
Application window: October is the most effective month for broadleaf weeds; never apply above 80°F or to drought-stressed turf
Iowa
Iowa hub →Crabgrass
🌾 Tall Fescue
Application window: October, and October is most of it — but check the wind and the date against what is happening in the fields, because early-summer growth-regulator drift is a real seasonal risk here and your own spray carries the same way
Kansas
Kansas hub →Spring dead spot on bermudagrassCrabgrassBuffalograss and bermudagrass encroaching as weeds in a fescue lawn, which is the transition zone working against you
🌾 Tall Fescue🌾 Zoysia
Application window: April into May and again in September–October; avoid July and August, when a tall fescue lawn here is already at its limit
Kentucky
Kentucky hub →Crabgrass
🌾 Zoysia
Application window: April–May and September–October; autumn is the knockout window for the wild garlic that defines a Kentucky winter lawn
Louisiana
Louisiana hub →🌾 Zoysia
Application window: March–May and October–November; avoid applications above 85°F and never on drought-stressed St. Augustine
Maine
Maine hub →Crabgrass (southern and coastal Maine more than the interior)
🌾 Tall Fescue
Application window: June, then a narrow late-August to mid-September window. Maine's usable autumn is the shortest in New England
Maryland
Maryland hub →Crabgrass
🌾 Zoysia
Application window: April–May and September–October; autumn is the knockout window for the ground ivy and violet the Piedmont is full of
Massachusetts
Massachusetts hub →Crabgrass
🌾 Tall Fescue
Application window: A narrow autumn is the real window here: late September into October, after the summer heat and before New England's early frost closes the season
Michigan
Michigan hub →Crabgrass
Application window: May–June and September; autumn is the stronger window for perennial broadleaf weeds
Minnesota
Minnesota hub →Crabgrass
Application window: Late May–June and September; autumn is the stronger window for perennial broadleaf weeds
Mississippi
Mississippi hub →Crabgrass
🌾 Zoysia
Application window: April–May and September, avoiding the midsummer heat restrictions on most labels
Missouri
Missouri hub →Crabgrass
🌾 Zoysia
Application window: April–May and September–October; skip summer sprays on drought-stressed fescue
Montana
Montana hub →Crabgrass and foxtail in the warmer valleys and in thin ground
🌾 Tall Fescue
Application window: June, then late August into September. In a sub-100-day valley there is no third chance
Nebraska
Nebraska hub →Crabgrass
🌾 Tall Fescue🌾 Zoysia
Application window: Late spring and again from late August through September, when perennial broadleaf weeds are moving reserves to the root
Nevada
Nevada hub →CrabgrassBermudagrass mites (southern lawns)
🌾 Tall Fescue
Application window: March–April and October in the south; May and September in the north
New Hampshire
New Hampshire hub →Crabgrass (heaviest in the south, thinning northward)
🌾 Tall Fescue
Application window: Late May into June, then late August through September. The autumn window closes earlier here than anywhere else in southern New England
New Jersey
New Jersey hub →Crabgrass
Application window: May and September–October; autumn is the knockout window for perennial broadleaf weeds
New Mexico
New Mexico hub →Spring dead spot on bermudagrass, appearing as the lawn greens upCrabgrass in irrigated turfBermudagrass encroaching into a northern bluegrass lawn, which is the transition zone working against youBermudagrass mites in the south
🌾 Tall Fescue🌾 Zoysia
Application window: Spring and early autumn; in the south skip the June heat entirely, and in the north the usable autumn window closes by early October
New York
New York hub →Crabgrass
Application window: May and September–October; autumn is the knockout window for perennial broadleaf weeds
North Carolina
North Carolina hub →Crabgrass
🌾 Tall Fescue🌾 Zoysia
Application window: April–May and September–October; avoid spraying heat-stressed fescue in July–August
North Dakota
North Dakota hub →Crabgrass, real but a smaller problem than further south
🌾 Tall Fescue
Application window: Early to mid-June, then late August into early September. There is no third opportunity
Ohio
Ohio hub →Crabgrass
🌾 Tall Fescue
Application window: May–June and September; fall applications hit dandelion taproots hardest
Oklahoma
Oklahoma hub →CrabgrassSandbur (the western sandy-soil weed that standard crabgrass preventers do not list)Bermudagrass mites
🌾 Zoysia🌾 Tall Fescue
Application window: Judged by wind before season: sustained wind is Oklahoma's normal condition, so the usable spray days are calm mornings in April, May and September rather than whole months
Oregon
Oregon hub →Crabgrass (east side and hot summers only)
🌾 Tall Fescue
Application window: March–May and September–October; the long mild shoulder seasons give more usable spray days than most states get
Pennsylvania
Pennsylvania hub →Crabgrass
🌾 Tall Fescue
Application window: May and September — fall is the knockout window for perennial broadleaf weeds
Rhode Island
Rhode Island hub →Crabgrass
🌾 Tall Fescue
Application window: Broadleaf work in May–June and again in September; the September pass is the one that holds, because the weed is moving reserves down
South Carolina
South Carolina hub →Crabgrass
🌾 Zoysia🌾 Tall Fescue
Application window: April–May and September–October, and never above 90°F — centipedegrass is sensitive to 2,4-D both at spring green-up and in summer heat
South Dakota
South Dakota hub →Crabgrass and foxtail in thin or disturbed ground
🌾 Tall Fescue
Application window: Early to mid-June, then late August into September, which is the pass that actually holds on perennial broadleaf weeds
Tennessee
Tennessee hub →Dallisgrass (a perennial the quinclorac that clears crabgrass will not touch)Crabgrass
🌾 Tall Fescue🌾 Zoysia
Application window: April–May and September–October; skip sprays on drought-stressed summer fescue
Texas
Texas hub →CrabgrassBermudagrass mites
🌾 Zoysia🌾 Tall Fescue
Application window: April–early June and September–October; avoid herbicides above 90°F
Utah
Utah hub →Crabgrass
🌾 Tall Fescue
Application window: May and September, avoiding the intense midsummer heat on the label
Vermont
Vermont hub →Crabgrass (a valley problem more than a hill-town one)
🌾 Tall Fescue
Application window: Late May through June, then a short late-August to mid-September window. Vermont's autumn window is the narrowest in New England
Virginia
Virginia hub →Crabgrass
🌾 Tall Fescue🌾 Zoysia
Application window: April–May and September–October; skip sprays on heat-stressed fescue in July and August
West Virginia
West Virginia hub →Crabgrass
🌾 Tall Fescue🌾 Zoysia
Application window: April into May and again in September–October. Skip July and August: this is transition-zone country and a heat-stressed tall fescue lawn absorbs the injury the weed does not
Wisconsin
Wisconsin hub →Crabgrass
Application window: Early to mid-fall is the favourable window for dandelion and other perennial broadleaf weeds
Wyoming
Wyoming hub →🌾 Tall Fescue
Application window: June, then late August into September. UW's own framing is useful: a slow-release application covers a 90 to 100 day growing season, which is roughly the entire Wyoming season
Common questions
Common Questions
How much does Gordon's Ornamec 170 Grass Herbicide, 32 oz cost?
Gordon's Ornamec 170 Grass Herbicide, 32 oz typically runs $38–$45, covering 32 oz concentrate; 2 fl oz per gallon treats 1,000 sq ft of tall fescue.
What does Gordon's Ornamec 170 Grass Herbicide, 32 oz treat?
Gordon's Ornamec 170 Grass Herbicide, 32 oz targets bermudagrass, crabgrass, grassy weeds in tall fescue, grassy weeds in zoysia.
What is the active ingredient in Gordon's Ornamec 170 Grass Herbicide, 32 oz?
Fluazifop-P-butyl 1.70%, registered under EPA Reg. No. 2217-751.
What is the biggest downside of Gordon's Ornamec 170 Grass Herbicide, 32 oz?
Label states do not apply to tall fescue turf unless injury can be tolerated — temporary discoloration is expected
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