The label is the law. Rates and restrictions below are taken from the product labels listed under Sources. Your product's own label governs; read it before you mix or apply. Mixing calculator · Disclaimer
- Active ingredient
- Fludioxonil (CAS 131341-86-1)
- Chemical class
- Phenylpyrrole; FRAC Group 12 PP fungicide acting on MAP/histidine kinase in osmotic signal transduction.[2][1]
- Mode of action
- FRAC Group 12: PP fungicides (phenylpyrroles): MAP/histidine kinase in osmotic signal transduction[2]
- Signal word
- Medallion SC Fungicide: Caution[1]
What it won't cover
Medallion SC is not the answer for Pythium blight or yellow tuft; the label points to a different fungicide for those. It is often paired with other turf fungicides for broader or longer protection.[1]
Limits and rotation
Use no more than 6 fluid ounces per 1,000 sq ft per year on turf. Sale and use are prohibited in Nassau and Suffolk counties, New York.[1]
To slow resistance, rotate with fungicides from other FRAC groups that control the same disease, or tank-mix them, rather than relying on Group 12 alone.[1][2]
Where it is used
Spray right after mowing, using enough water for thorough coverage. For leaf diseases, let the turf dry completely before irrigating.[1]
It works as a preventive. When weather strongly favors disease, use the higher rate and the shorter interval.[1]
Get the disease identified first. The label calls proper diagnosis essential, using diagnostic kits or other identification.[1]
For snow mold, apply in late fall before snow arrives, never on top of snow.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Medallion SC Fungicide[1] | Syngenta Crop Protection, LLC | 100-1448 | 11.8% | suspension concentrate (1.04 lb fludioxonil per gallon) | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Medallion SC Fungicide | Lawns, golf courses, sod farms, sports fields, parks and cemeteries | Brown patch (Rhizoctonia solani) | 0.75–2.0 fl oz product per 1,000 sq ft[1] 0.75 to 1.0 fl oz every 7 days, or 2.0 fl oz every 14 days. Start before the disease shows up. |
| Medallion SC Fungicide | Lawns, golf courses, sod farms, sports fields, parks and cemeteries | Anthracnose, leaf spot, gray leaf spot, Microdochium (Fusarium) patch | 1.0–2.0 fl oz product per 1,000 sq ft[1] Every 14 days for anthracnose and gray leaf spot, 14 to 21 days for leaf spot, and 7 to 14 days for Microdochium patch without snow cover. |
| Medallion SC Fungicide | Cool-season turf before winter | Pink snow mold and gray snow mold | 2.0 fl oz product per 1,000 sq ft[1] One or two applications in late fall before snow cover, tank-mixed with other snow mold products. 1.0 to 1.15 fl oz is allowed in certain three-way mixes when pressure is light to moderate. |
Safety and environmental hazards
People
Signal word CAUTION: harmful if swallowed and causes moderate eye irritation. Handlers wear long sleeves, long pants, shoes, socks and chemical-resistant gloves.[1]
Pets
Outside farm settings, the label says not to enter treated areas without protective clothing until sprays have dried. Keep pets off until then, and don't graze animals on treated turf or feed them clippings.[1]
Bees and pollinators
Medallion SC's label carries no bee or pollinator statement.[1]
Fish and water
Toxic to fish, aquatic invertebrates, oysters and shrimp. The label warns of high runoff potential for several months and possible groundwater contamination in permeable soils.[1]
Common questions
- How often can Medallion SC be sprayed for brown patch?
- Every 7 days at 0.75 to 1.0 fl oz per 1,000 sq ft, or every 14 days at 2.0 fl oz, within the 6 fl oz yearly cap.[1]
- Does fludioxonil control Pythium blight?
- No. The label lists Pythium blight and yellow tuft as diseases needing a different product.[1]
- Can Medallion SC be used on home lawns?
- Yes. Residential lawns are among the listed sites, alongside golf courses, sod farms, sports fields, parks and cemeteries. It is sold as a professional product.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Medallion SC label, EPA Reg. No. 100-1448 (EPA-stamped, Feb. 2, 2022).” www3.epa.gov/pesticides/chem_search/ppls/000100-01448-20220202.pdf (accessed 2026-10-06)
- Fungicide Resistance Action Committee, “FRAC Code List 2025.” www.frac.info/media/ljsi3qrv/frac-code-list-2025.pdf (accessed 2026-10-06)