The Best Fungicides to Use on Your Lawn
Choosing the best fungicide for lawns starts with identifying the specific lawn fungus or disease damaging your turf. Whether you need a brown patch fungicide, a broad-spectrum lawn fungicide, or an all-in-one fungicide for lawns and pests, using the right product ensures you don’t waste time or money.
- Headway G (azoxystrobin and propiconazole) is a broad-spectrum granular fungicide that targets many common lawn fungi. It controls brown patch, dollar spot, fairy ring, and more.
- Pillar SC Intrinsic® Brand (triticonazole and pyraclostrobin) is a fast-acting liquid fungicide that controls up to 26 cool and warm-season common turfgrass diseases. It is safe for all grass types.
- If you have a fungal issue and a pest problem, Caravan® G (azoxystrobin and thiamethoxam) is the best fungicide for your lawn.
What Are Fungi?
Fungi are the most common parasites that cause plant disease. Preventing weeds, pests, and fungi from infesting your grass comes down to consistent lawn management and care. Healthy and strong grass is at far less risk of inviting in our fungal foes. Lawns are naturally full of fungal spores, which usually don’t cause any harm to your grass. However, certain conditions can cause these spores to germinate and lead to diseases like red thread and brown patch. Here are a few common causes of lawn fungus that you can easily prevent:
Underwatering or overwatering your lawn — Grass types like Bermuda only need about an inch of water during summer. For more lawn watering tips, check out our YouTube video:
Compacted soil: Remedy this by aerating your soil and perforating the grass with small holes to allow air, water, and nutrients to penetrate down to the roots.
Leaving the grass too long or cutting it too short: To achieve a perfect lawn, we recommend mowing the grass three times a week. You should cut off no more than a ⅓ of the grass’s entire length.
Too much fertilizer: Excess fertilizer can encourage weeds and fungi to grow, as well as your grass.
Weather conditions: High humidity and cold, damp conditions can stimulate fungi growth.
Aside from deploying preventative measures, lawn fungus can still make its way into your lawn. Before treatment, it’s essential to identify what you’re dealing with. Read on to find out how to spot common lawn fungi and the most effective fungicides to treat them.
Related: Lawn Recovery After Heavy Rain and Fungus Attacks: A Six-Step Strategy
What Are Fungicides?
Fungicides fall under the category of pesticides. They can prevent, kill, or inhibit fungi growth, but can’t be used against bacteria or viral diseases. Fungicides can be classified in these ways:
- Contact fungicides, also known as protectants, aren’t absorbed by the plant and stick to leaf surfaces. This forms a barrier on the plant that stops the fungus from entering and damaging plant tissues.
- The entire plant absorbs penetrants.
- Preventative fungicides stop the fungus from reaching the plant, although they must come into direct contact with the fungus, so reapplication might be necessary.
- Curative fungicides target the fungus after infection has begun, or the first symptoms are visible.
Now that you have a better understanding of the types of fungicides available, it’s time to identify the lawn fungus causing damage to your turf.
Why Is My Lawn Turning Brown in Spots? Common Lawn Fungus Types Explained
Fungal diseases are prevalent when your lawn suffers environmental stress. This varies according to grass-growing regions. Warm-season grasses become vulnerable when abnormally cool conditions slow their growth, and the opposite is true for cool-season grasses. Too much rain, drought, or overcast skies will affect your lawn’s ability to fight back against fungal diseases.
We’ve compiled a list of some of the most common fungal lawn diseases for warm — and cool-season grasses and instructions on identifying them.
Related: Turf Wars: How to Treat Lawn Fungus
Brown Patch Lawn Disease
This is an easy one to look out for. Brown patch is caused by the fungus Rhizoctonia solani and is one of the most widespread lawn diseases. You’ll see circles of dead, sunken grass, varying in size from a few inches to several feet. The circle’s perimeter will appear light gray in periods of high humidity.
The most vulnerable grass types are:
- Perennial ryegrass
- Tall fescue (and fine fescue grasses)
- Bentgrass
- Bermuda grass
- Kentucky bluegrass
- St. Augustine.
Brown patch lawn disease is most likely to occur in warm or hot weather conditions in the spring and fall. Wet leaves, excess water, and over-fertilizing all contribute to its spread.
For more information, read our blog: How to Get Rid of Brown Patch Fungus on Your Lawn
Dollar Spot Lawn Disease
This lawn disease starts with silver dollar-size circles that can spread up to six inches wide, merging eventually into large blocks. Your grass will start developing yellow spots with a brown border that look water-soaked. You might also notice cobweb-like growth in the grass in bright lighting.
The most vulnerable grass types are:
- Tall fescue (and fine fescue grasses)
- Perennial ryegrass
- Bentgrass
- Centipede grass
- Kentucky bluegrass
- Bermuda grass
- Zoysia grass.
Dollar spot disease can develop from late spring to fall, favoring mild-to-warm temperatures. Excess moisture or too little moisture and under-fertilizing can leave grasses more susceptible to this disease.
Learn more about: How to Control Dollar Spot.
Red Thread Lawn Disease
Photo taken by Pete Dernoeden, PhD
Grass blades begin to wither from the tips as red or bleached-looking patches form. You’ll notice that reddish-pink threads bind together grass blades, and red spores will appear on your shoes or tools.
The most vulnerable grass types are:
- Fine fescue
- Perennial ryegrass
- Bluegrasses
- Bentgrass.
Red thread lawn disease prefers mild temperatures in early spring and enjoys wet conditions. Under-fertilizing, poor air circulation, shade, excess thatch, compacted soil, and wet leaves contribute to this condition.
Read more about: Red Thread Disease Control
Rust Lawn Disease
The clue is in the name. Rust lawn disease forms irregular patches of thinning grass, which develop yellow specks, becoming rust-colored. Orange spores cover grass blades — so like red thread, you’ll start noticing these spores on your tools, shoes, and mower.
The most vulnerable grass types are:
- Tall fescue (and fine fescue grasses)
- Perennial ryegrass
- Kentucky bluegrass
- Zoysia grass
- Bentgrass.
Moderately warm or mild temperatures facilitate rust lawn disease, so your grass is most susceptible in early summer and fall. Drought, hot weather, excessive moisture, too much shade, and under-fertilizing are all common causes of rust.
Read more about how to: Get Rid of Lawn Rust Disease
Snow Mold Lawn Disease
Snow mold lawn disease begins with small, circular pinkish spots that can spread up to a foot in length. The grass blades become soaked with water, particularly under snow, turning red-brown. In the morning light, you’ll easily see white fungal threads that resembling frost.
The most vulnerable grass types are:
- Tall fescues (and fine fescue grasses)
- Bentgrass
- Perennial ryegrass
- Kentucky bluegrass.
Cold temperatures in the fall, combined with heavy rainfall, allow snow mold to strike in winter. The excess nitrogen from over-fertilization, poor drainage, and too much shade, can make grass more susceptible to this disease.
Of course, these aren’t the only lawn diseases out there. We recommend identifying your fungal infection before proceeding with treatment and management.
Related: Managing Winter Lawn Disease
The Best Fungicides for Your Lawn — Syngenta and BASF Fungicides
You’ve tried your best to maintain a healthy lawn, but sometimes pests, weeds, and fungi still find a way in. If that sounds like you, it’s time to bring out the lawn fungicides. But which ones do you choose? Luckily, we’ve got two highly effective fungicides that directly target and mitigate lawn fungus in your grass, brought to you by esteemed manufacturer Syngenta.
Caravan® G — Granular Insecticide and Fungicide
This is the best fungicide for your lawn if you have a pest problem and a potential fungal issue. Caravan® G is a granular insecticide and fungicide that provides exceptional insect and fungus control with a single application. The two active ingredients (azoxystrobin and thiamethoxam), combined, target grubs, craneflies and chinch bugs to name a few. Lawn fungi controlled by Caravan® G include brown patch, fairy ring, large patch, and more.
This fungicide can provide grub control for an entire season and a month of preventative large patch control. Because this product combines an insecticide and fungicide, it’s more economical than applying two separate products, saving you time and money. Apply between May and July for the best results. Note that this is a preventative fungicide, so if you’re dealing with an active fungus outbreak, apply Headway G fungicide 28 days later.
The product is safe for use on residential and commercial turfgrass and harmless to people and pets when used correctly.
Application Tips:
- Coverage: One bag treats 10,700 to 15,000 sq. ft.
- Best Time to Apply: Late spring to early summer (May–July) for preventative control of lawn fungus and grubs.
- Application Method: Use a broadcast spreader for even distribution.
- Watering Tip: Lightly water the lawn (about 0.2–0.3 inches) after application to activate the grass fungicide and move it into the soil. Avoid heavy watering that might wash the product away.
- Pro Tip: For active fungal infections, follow up with a curative fungicide like Headway G after 28 days. Caravan® G is designed for preventive use.
Headway G — Fungicide Granular
Headway G offers a one-stop granular solution for homeowners wondering how to treat lawn fungus like brown patch. Brown patch, dollar spot, fairy ring, and more can be mitigated with a single application. Headway G contains two broad-spectrum fungicides that work together to eliminate a wide range of lawn fungi. This kind of fungicide coverage often requires two or more products. Here, you get it all in one.
Safe for people and pets, save time and money, avoiding countless applications with multiple products.
Application Tips:
- Coverage: One bag treats 8,500 to 15,000 sq. ft.
- Best Time to Apply: Early in the disease cycle at the first signs of brown patch, dollar spot, or fairy ring. Suitable for both preventative and curative fungicide applications.
- Application Method: Apply evenly using a broadcast spreader for thorough coverage.
- Watering Tip: Lightly irrigate the treated area immediately after application to activate the lawn fungicide and move it into the root zone.
- Pro Tip: For extended protection during high-risk conditions (humidity, overwatering), reapply every 14 to 28 days depending on disease severity.
Pillar SC— Liquid Fungicide
If you’re looking for a fast-acting liquid grass fungicide to deliver exceptional disease control, Pillar SC Intrinsic® Brand Liquid Fungicide is an excellent choice. It controls up to 26 cool and warm-season common turfgrass diseases like brown patch and dollar spot, and is safe for all grass types. It’s considered one of the best fungicides for lawns needing quick curative action.
Application Tips:
- Coverage: One bottle covers up to 43,500 sq. ft.
- Best Time to Apply: At the first sign of turfgrass disease (brown patch, dollar spot, leaf spot). It can also be used preventively before peak fungal seasons.
- Application Method: Mix with water according to label instructions and apply using a backpack sprayer. Use a flat fan spray tip to ensure even application across turfgrass blades for best coverage.
- Watering Tip: Do not water the lawn immediately after applying fungicide. Allow the product to fully dry (about 24 hours) to ensure optimal absorption.
- Pro Tip: Pillar SC Intrinsic® Brand has a single application rate for all diseases, making it easy to mix and apply without complicated dosing.
Related: How to Get Rid of Fairy Ring Disease in Your Lawn
Lawn Disease and Fungicide FAQs
Q. How to treat grass fungus effectively?
A. To treat grass fungus, start by identifying the type of fungus (e.g., brown patch, dollar spot). Apply a targeted lawn fungicide and correct contributing factors like overwatering, poor mowing habits, or excessive fertilization.
Q. Should you water the lawn after applying fungicide?
A. For granular products like Headway G, lightly water your lawn to activate the fungicide for lawn fungus. However, avoid watering for at least 24 hours after liquid applications like Pillar SC Intrinsic® Brand to ensure effective absorption.
Q. What kind of fungicide should I use on the lawn for brown patch?
A. The best brown patch fungicide is a broad-spectrum product like Headway G or Pillar SC, which contain propiconazole and azoxystrobin. These ingredients target Rhizoctonia solani, the fungus responsible for brown patch.
Q. Is lawn rust harmful to pets?
A. Lawn rust fungus is not harmful to pets but can stain their fur or your shoes with orange spores. Apply a suitable fungicide for lawns to eliminate rust and reduce spore spread.
Q. How often should I apply fungicide to my lawn?
A. Apply preventative fungicides for lawns like Caravan® G at the start of the growing season. For curative treatments, follow product instructions, typically reapplying every 14 to 28 days if symptoms persist.
Q. Can I apply lawn fungicide and fertilizer at the same time?
A. It’s best to avoid applying fungicide for lawns and fertilizer simultaneously unless using a combination product designed for both. Over-fertilizing during a fungal outbreak can worsen the problem. Apply fungicide first, then wait 10-14 days before fertilizing.
Q. Do I need to mow before applying fungicide to my lawn?
A. Yes, mowing before applying a lawn fungicide ensures better product contact with the grass blades. However, avoid mowing immediately after application to allow the fungicide time to work effectively.
Q. How long does it take for lawn fungicide to work?
A. Most fungicides for lawn fungus begin to show visible results within 7 to 14 days of application. For severe infections, multiple treatments may be required, spaced 14-21 days apart, may be required.
Q. Can I walk on my lawn after applying fungicide?
A. Once a lawn fungicide has dried (usually within 2-4 hours for liquids or after light watering in granular products), it is safe to walk on the lawn. Always follow the product label for specific re-entry instructions.
Q. Can lawn fungus spread to my garden plants or trees?
A. Most lawn fungi are turf-specific and won’t affect garden plants or trees. However, some fungal spores can spread in wet conditions. Applying a lawn fungicide will help contain outbreaks to the turf area.
Q. What environmental factors increase lawn fungus problems?
A. High humidity, overwatering, compacted soil, excessive shade, and poor air circulation create ideal lawn fungus conditions. Correcting these cultural factors alongside fungicide application gives the best control.
Preventing and Targeting Lawn Fungi
Keeping your grass in good condition helps prevent the onset of lawn fungi. Keep an eye on the weather, bearing in mind the circumstances in which fungi thrive. For example, use a home soil test kit to determine the pH level of your soil — most grasses require a neutral pH.
Use grasses recommended for your region and ensure you fertilize properly (not too little or too much). Also, remember to dethatch your lawn and regularly aerate your grass to discourage pests and fungi. It might seem like a challenging routine, but if you want to achieve a perfect golf course lawn, you must be proactive.
Golf Course Lawn can help you prevent and eliminate invasive lawn fungi. Browse our range of highly effective insecticides and fungicides to get a healthy, vibrant lawn.
Ron Henry
Ron Henry is the founder of Golf Course Lawn, which is dedicated to helping homeowners achieve golf course-quality lawns. He holds a certificate in Sports Turfgrass Management from the University of Georgia. With expert knowledge in turf care, fertilization, and weed control, he shares practical tips and product recommendations to create lush, healthy lawns.