Common Fall Lawn Diseases in Florida (and How to Stop Them)

Florida’s fall season might feel like a relief after months of blazing heat, but for your lawn, it’s a tricky time. It’s not just cooler—it’s also the start of the dry season, when rainfall tapers off but humidity and dew still linger. This mix of hot and humid weather during the day, cooler nights, and patchy rain creates the perfect environment for fungal growth. Add in morning dew, uneven watering, and poor soil drainage, and you have the ideal setup for disease development in your yard.

Even hardy warm-season grasses like St. Augustine and bermudagrass can struggle under these shifting conditions. Thatch buildup and compacted soil trap moisture close to the roots, feeding fungal spores waiting for their chance to spread. When lawns stay damp overnight and dry out too quickly during the day, the risk of infections like brown patch fungus, dollar spot, and rust skyrockets.

Starting with healthy, resilient sod is one of the best defenses against these problems. Bethel Farms sod is grown in carefully managed fields, where experienced growers monitor conditions, address stress factors, and ensure each pallet is dense, disease-resistant, and ready to thrive—even when Florida’s unpredictable fall and dry season weather puts your turf to the test.

Brown Patch Disease: The Common Fall Culprit

Brown patch disease is one of the most widespread lawn issues in the fall and early winter. Caused by the fungus Rhizoctonia solani, it thrives in species like St. Augustinegrass, zoysiagrass, and bermudagrass—particularly when nights are cool and soil stays wet.

How It Starts

This disease often begins when lawns are overwatered or when too much nitrogen fertilizer is applied during early spring or fall. The fungus is triggered when grass blades remain damp for extended periods, especially in shaded areas with poor drainage or compacted soil. Once active, the infection spreads quickly, forming circular patches that range from a few inches to several feet wide.

Brown Patch Symptoms

At first, patches of light brown grass that seem water-soaked or greasy may become visible. As the infection progresses, the patches develop dark brown borders that clearly separate infected grass from healthy turf. Look closely at the leaf blades—they may have lesions or appear wilted and thin. These signs indicate active disease development.

Does It Spread?

Yes, brown patch fungus can spread fast, especially if you mow or walk across wet areas. Spores move through water, wind, and contaminated tools, making controlling brown patch crucial before it overtakes your entire lawn.

Brown Patch Treatment and Recovery

To regain control, focus on improving grass and soil conditions:

• Increase air circulation and reduce shade.

• Avoid watering in the evening; water early in the morning instead.

• Correct poor soil drainage with aeration or topdressing.

• Apply fungicide treatments labeled for control of brown patch if the disease continues spreading.

Healthy lawns usually recover within 2–4 weeks, depending on the severity. The best approach is prevention—maintain balanced fertilization, mow to the recommended height, and prevent excessive thatch buildup. These practices not only prevent brown patch but also strengthen your lawn against future infections.

See Also: Lawn Fungi: Signs of Fungal Infection in Grass

Dollar Spot: Small Spots, Big Damage

Dollar spot, a disease that may seem minor at first glance, can quickly ruin your lawn’s appearance. This fungal infection, caused by Clarireedia jacksonii, thrives in warm, moist conditions and lawns that are slightly nutrient-deficient.

How It Spreads and What It Looks Like

Dollar spot thrives when grass species like bermudagrass and zoysiagrass are under stress or lacking nitrogen. The disease starts as small, circular patches—each about the size of a silver dollar—but these spots can merge into large, irregular areas over time. You might also notice a faint white or cobweb-like mold on the surface in the early morning.

Dollar Spot Treatment

• Apply balanced nitrogen to boost turf growth and repair damage.

• Mow with sharp blades and avoid cutting too short—keep grass at a few inches high to promote density and resilience.

• Use chemical control treatments designed for dollar spot if the infection persists.

By improving lawn nutrition and reducing surface moisture, you can stop the spread and bring your turf back to its lush green self in no time.

Lawn Rust: The Sneaky Orange Dust

Unlike the other two, lawn rust often sneaks up on you slowly. It’s caused by several fungal species that produce fine orange or yellow powder on the leaf blades—which is actually millions of spores. While grass rust looks alarming, it’s not harmful to humans, pets, or wildlife.

Why It Happens

Rust tends to appear when lawns grow slowly, either due to low fertility, shade, or drought stress. It’s especially common in St. Augustine, bermudagrass, and zoysiagrass lawns during transitional weather.

Does It Go Away on Its Own?

In mild cases, yes. When growth picks up again, healthy blades outgrow the infected ones. However, persistent rust weakens turf over time, making it vulnerable to other problems like weeds or large patch disease.

How to Treat Lawn Rust

• Mow regularly and bag clippings to remove spores.

• Apply moderate fertilizer to promote healthy growth.

• Water deeply but infrequently to avoid constant leaf wetness.

If rust keeps returning, check for poor drainage or compacted soil—both encourage moisture retention and disease development.

Preventing Fall Lawn Diseases Before They Start

Prevention is the most effective—and least expensive—approach to lawn care. By keeping your turf healthy and reducing stress, you can make your lawn naturally resistant to most fungal issues. Here are some reliable habits for controlling brown patch, dollar spot, and rust:

• Mow properly: Never scalp your grass. Maintain optimal height depending on your turfgrass species—for example, St. Augustine at 3.5–4 inches and bermudagrass slightly lower.

• Water wisely: Morning watering allows leaf surfaces to dry quickly, reducing fungal activity.

• Aerate compacted soil: Improves air exchange and water penetration, especially in heavy clay or sandy areas.

• Fertilize carefully: Too much nitrogen can worsen brown patch symptoms, while too little encourages dollar spot and rust.

• Improve airflow: Trim overgrown shrubs and trees to reduce humidity near the turf canopy.

How Bethel Farms Sod Helps

Bethel Farms is a trusted sod farm offering sod grass for sale across Florida, helping homeowners restore their lawns quickly and effectively. After any infection has been resolved, fresh sod can help speed up recovery by providing dense, healthy growth from day one. We offer a wide range of varieties bred for Florida’s unique climate including:

• Floratam St. Augustine: Perfect for full-sun lawns and high disease resistance.

• Palmetto and CitraBlue St. Augustine: Excellent for shade and moisture tolerance.

• Bimini® Bermudagrass: Fine-textured, fast-growing, and resilient—ideal for lawns or golf courses.

High-quality sod provides uniform coverage, minimizing bare spots where fungus thrives and promoting long-term resilience against disease.

Bringing Your Lawn Back to Life

Even the best lawns sometimes fall victim to disease, but recovery is possible with consistent care. Most warm-season grasses can regrow from their roots once conditions improve. However, if large areas remain thin or dead, it’s often best to replace sod rather than wait months for natural recovery.

Re-sodding jumpstarts the recovery process. Because it’s grown in optimal conditions, it establishes quickly and resists future infections. Think of it as pressing the reset button—giving your lawn a fresh, healthy foundation that can withstand Florida’s demanding climate.

Key Takeaway

Florida’s fall season can be a test for your lawn, but it doesn’t have to be a losing battle. Understanding how fungal diseases form and knowing how to manage moisture, nutrition, and mowing habits make all the difference.

Whether you’re fighting brown patch fungus, dollar spot, or rust, prompt action and proper care will help your turf bounce back stronger. And when recovery calls for new growth, trust Bethel Farms to deliver premium-quality grass—disease-resistant, expertly cultivated, and ready to thrive across every Florida season.

Rebuild your lawn’s health and beauty with disease-resistant sod grass for sale from Bethel Farms—grown for Florida lawns and built to thrive through every season.