Having a thick and healthy lawn requires more than just fertilizers and herbicides. Fungus control plays an important role in proper lawn care. Untreated lawn disease are not only unsightly, but these grass diseases can spread very quickly and kill your lawn in no time.
Be sure to treat brown patch fungus with the right fungicide. The FRAC group, application rates and intervals, and rotation is key to arresting the spread of brown patch disease, and eliminating the unsightly coloring from your lawn.
Be sure to prevent fungicide resistance by rotating fungicide FRAC groups every 1-2 applications. If used too frequently/consecutively, the fungus will develop a resistance to the active ingredient and become unaffected. Azoxystrobin will treat brown patch for up to 28 days, while Pyraclostrobin, Propiconazole, and will control the diseases for 14 days. Rotating Azoxy with Propiconazole is a terrific 1-2 punch in fighting fungus and diseases.
Below are the best fungicides for lawns and brown patch. They are in three different FRAC groups so they can be used safely and effectively at preventing and treating fungus and diseases in your lawn.
Active Ingredients: Propiconazole
Target Funguses: Brown Patch, Dollar Spot, Leaf Spot, Pink & Gray Snowmold, Powdery Mildew, Rust and more.
FRAC Group 3
Quite possibly the most economical and effective fungicides out there, Propiconazole can prevent and control some turf diseases for up to three weeks.
Purchasing a gallon of Propiconazole 14.3 and applying minimum rates for brown patch costs $0.90 per 1,000, while 2 oz. per 1,000 sq. ft. is just $1.81 per 1,000 sq. ft. application. The 128 oz. jug will cover over an acre at the 2oz. per 1,000 sq. ft. application rates.
Propiconazole at 2-4 oz. per 1,000 sq. ft. is also a great option at the end of the season to prepare your lawn for winter and help prevent snow mold in the spring. For this price, it should be on your shelf and in regular rotation.
2. Artavia 2 SC
Active Ingredients: Azoxystrobin
Target Funguses: Over a dozen diseases including Brown Patch, Leaf Spot, Melting Out, Red Thread, Pythium Blight, Snow Mold, Take All Patch and more.
FRAC Group 11
Azoxystrobin is one the most powerful ingredients against many diseases, and Artavia 2 SC is a terrific broad-spectrum liquid fungicide. Apply just 0.38-0.77 oz. per 1,000 for 10-28 days of disease coverage (depending on type of fungus). While it’s a more expensive up front coast than Propiconazole, low rates will cover almost an acre of turf. The same active ingredient as bigger named Heritage, Atticus offers the same active ingredients as a generic option and at a much more affordable cost.
This product, alternatively applied with Propiconazole, will be one of the best 1-2 combinations in preventing lawn disease like brown patch fungus.
Active Ingredients: Triadimefon and Trifloxystrobin
Target Funguses: Brown Patch, Dollar Spot, Leaf Spot, Rust, Pink Snow Mold and more.
FRAC Group 3 & 11
Armada 50 WDG is a terrific option at preventing many lawn diseases. It is a powerful combination of FRAC 3 and FRAC 11 fungicides. This water dispersable granule (WDG) needs to be mixed and fully dissolved and suspended before spraying. Use up to 1.5 ounces (42.5 grams) per gallon per 1,000 sq. ft.
Use this broad spectrum fungicide early to help mitigate many fungus issues earlier in the season.
Active Ingredients: Pyraclostrobin and Triticonazole
Target Funguses: Over 20 diseases including Brown Patch, Dollar Spot, Melting Out, Pythium Blight, Red Thread, Rust and more.
FRAC Group 3 & 11
Pillar G is one of the few granular fungicides that we recommend. Generally speaking, liquid fungicides are much better options for treating lawn fungus. Granulars need to be watered into the soil and its ingredients drawn up through the roots; where liquids can be sprayed directly onto the grass blades and become more quickly activated into the grass foliarly.
Apply 3 lbs. of Pillar G per 1,000 sq. ft. to control a broad spectrum of funguses.
Active Ingredients: Thiophanate-methyl
Target Funguses: Anthrancose, Brown Patch, Dollar Spot, Leaf Spot, Red Thread, Snow Mold, Rust, Summer Patch and more.
FRAC Group 1
Clearys 3336 F fungicide is broad spectrum fungicide providing very good disease prevention and curative properties for turfgrasses. This FRAC 1 fungicide is a great option to rotate with any of these other fungicides listed in this post (FRAC 3 & 11). Apply between 2-6 oz. per 1,000 sq. ft. depending on the type of disease.
Note: there are several restrictions and may not be available in your state.
Active Ingredients: Myclobutanil
Target Funguses: Brown Patch, Dollar Spot, Red Thread, Necrotic Ring Spot, Leaf Spot, Powdery Mildew, Red Thread, Rust
FRAC Group 3
Since Clearys has some restrictions, we threw in a bonus fungicide here. Eagle 20EW is a FRAC 3 fungicide containing Myclobutanil. Eagle 20EW is a broad spectrum systemic fungicide that targets over 15 different diseases. Rotate with Azoxystrobin (Artavia 2 SC) for a solid 1-2 punch against many diseases including Brown Patch. You can also find the generic version here.
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Lawn Fungicides FAQs
For applying fungicides to lawns and turfgrass, fill the tank with half of the total water needed. Next, pour in the measured amount of fungicide liquid. Last, fill with the remaining half of the water and agitage. If mixing directly into your tank, a paint mixer makes suspension quick and easy.
The risk of disease and fungus increases as the outside temperatures and humidity levels rise. A good rule of thumb is to add the outside temperature (fahrenheit degrees) + humidity percentages. If that number is 150 then it’s time to apply. This is when fungus begins to thrive.
Whenever possible, try buying liquid fungicides listed here first. The cost for these products are higher than those at the big box stores, but the cost per application is generally much cheaper. Example, Bayer Bio Advanced contains propiconazole and is cheaper than 14.3, but the cost per application (1,000 sq. ft.) is about 3x ($5.20 vs $1.81)
Always read the labels. The application rates and intervals will always vary from both product-to-product, and which disease you’re targeting. Some fungicides can be applied as early as 7-10 days while others can be 21-28 days.
It’s important to know that fungicides will help arrest or stop the fungus from spreading, and not “kill” the disease. Generally turfgrass diseases start at the top of the grass blades and work its way down to the crowns – at which point will kill the grass. Fungicides will help prevent the growth of the disease, giving it more time to grow out.