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 diseases 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 fungicides. The FRAC groups, application rates and intervals, and rotation is key to arresting the spread of brown patch disease and eliminating the unsightly coloring from your lawn.
To prevent fungicide resistance, make sure you are rotating the types of fungicides and 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.
- 1 1. Propiconazole 14.3
- 2 2. Artavia 2 SC
- 3 3. Armada 50 WDG
- 4 4. Pillar G Intrinsic Granular Fungicide
- 5 5. Clearys 3336F Fungicide
- 6 6. Eagle 20EW Specialty Fungicide
- 7 What Are Fungicides?
- 8 Lawn Fungicide FAQs
- 9 How do you mix lawn fungicides?
- 10 When should I apply fungicide prevention?
- 11 What fungicides should I buy at hardware stores?
- 12 How frequently can I apply fungicides?
- 13 How can I kill brown patch fungus and other diseases in my 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 systemic 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. This can also prevent and treat many other diseases in your landscape beds. I’ve recently treated anthracnose in my azalea this year with both Propiconazole and Artavia 2SC (below), and is now in full bloom!
For this price, it should be on your shelf and in regular rotation. I use 2 oz. per 1,000 sq. ft. in early May as my first round fungicide.
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 of 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 the type of fungus). Try our Azoxystrobin calculator to help get the exact amount you need for your lawn.
While it’s a more expensive upfront cost than Propiconazole, low rates will cover almost an acre of turf. The same active ingredient as bigger named Heritage G (granular), 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 diseases like brown patch fungus. For a granular alternative, Syngenta Heritage G is the one.
These two products and types of fungicides need to be on your shelves. I apply Artavia at the end of May as my Round 2 application. I successfully use Artavia 2SC on my hydrangeas to help prevent things like leaf spot, too.
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 for those looking for an all-in-one solution. It is a powerful combination of FRAC 3 and FRAC 11 fungicides. This water dispersible 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. Make sure to rotate with other non Group 3 or 11 fungicides every two applications.
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 lawn fungus control. 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.
Best used as a prevention. Apply 3 lbs. of Pillar G per 1,000 sq. ft. to control a broad spectrum disease prevention of funguses. Be sure to rotate with other non Group 3 or 11 fungicides every two applications.
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 disease prevention 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 fungal diseases.
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 lawn fungicide here. Eagle 20EW is a FRAC 3 fungicide containing Myclobutanil. Eagle 20EW is a broad spectrum systemic fungicide that targets over 15 different grass 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.
What Are Fungicides?
Fungicides are used in lawns to help prevent and control fungal diseases. Fungicides do not cure or fix the infected grass but do provide a curative response that helps stop the growth and spread of the disease in the plant. When left untreated, lawn diseases can kill the lawn to the point of needing full repairs.
Fungicides do not control or prevent insect damage. Follow the instructions on the fungicide label for long‐term protection and eradicate activity against lawn fungus and diseases.
Liquid fungicides are better than granular fungicides. When applied to the turf with an active lawn disease, these fungicides provide a “curative” response that helps stop or arrest the growth and spread of the fungus. When left untreated, lawn diseases can kill the lawn to the point of needing full repairs.
Liquids in particular have broad-spectrum control and provide protective, systemic, and curative activity. Because resistance can develop over time, rotating different modes of action is important. For example, rotate propiconazole and azoxystrobin (every other application).
Lawn Fungicide FAQs
How do you mix lawn fungicides?
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 agitate. If mixing directly into your tank, a paint mixer makes suspension quick and easy.
When should I apply fungicide prevention?
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.
What fungicides should I buy at hardware stores?
Whenever possible, try buying liquid fungicides listed here first. The cost for these products is higher than those at the big box stores, but the cost per application is generally much cheaper. For 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). We do not recommend Scotts DiseaseEx lawn fungicide.
How frequently can I apply fungicides?
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.
How can I kill brown patch fungus and other diseases in my lawn?
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 their 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.