Lawn Care Tips & Guides | Weed Away Blog

Lawn Diseases: Identify, Prevent, and Treat

Written by Bobby | August 2024

Learn how to spot, stop, and prevent common lawn diseases to keep your grass green and healthy year-round.

Introduction

Welcome to the Ultimate Guide to Lawn Diseases

A healthy lawn makes your home look beautiful, but sometimes diseases can ruin it. Lawn diseases can turn your green grass into brown patches and make it look unhealthy.

This guide will help you learn about common lawn diseases, and how to identify them, prevent them, and treat them. With these tips, you can keep your lawn looking its best all year round.

Start creating and maintaining the lawn of your dreams today!

Understanding Lawn Diseases

What Are Lawn Diseases?

Lawn diseases are problems caused by fungi, bacteria, or other organisms that affect your grass. They can make your lawn look bad and unhealthy. These diseases can spread quickly if not treated properly.

Why Do Lawn Diseases Happen?

Lawn diseases often occur because of poor lawn care practices. Too much water, too little water, cutting the grass too short, or not fertilizing correctly can all lead to problems. Weather conditions like too much rain or heat can also contribute to lawn diseases.

How Do Lawn Diseases Affect Your Grass?

Diseases can cause different symptoms like brown patches, yellow spots, or fuzzy mold. They weaken the grass, causing it to die or allowing weeds to overtake it. Knowing the signs can help you take action before it's too late.

Identifying Lawn Diseases: A Closer Look at Common Grass Problems

In this section, we'll explore the common types of lawn diseases.

Brown Patch

Description: Brown Patch is a common lawn disease caused by the fungus Rhizoctonia. It is most active in hot, humid weather, typically during the summer.

Symptoms:

  • Large, round, brown spots that can range from a few inches to several feet wide.
  • Grass in the affected area may appear water-soaked and thin.
  • The edges of the patches are often dark and irregular.

Prevention and Treatment:

  • Avoid too much water at once and water early in the day to allow grass to dry.
  • Improve air circulation by mowing at the proper height and avoiding excessive thatch.
  • Apply fungicides if necessary, following label instructions.

Dollar Spot

Description: Dollar Spot is caused by the fungus Clarireedia jacksonii. It thrives in warm, humid conditions and affects lawns with low nitrogen levels.

Symptoms:

  • Small, round, tan spots about the size of a silver dollar (hence the name).
  • Spots may merge to form larger patches.
  • Grass blades have white or tan lesions with reddish-brown borders.

Prevention and Treatment:

  • Maintain proper nitrogen levels through regular fertilization.
  • Water deeply but infrequently, allowing the soil to dry between watering.
  • Use fungicides as a preventive measure during peak disease periods.

Pythium Blight

Description: Pythium Blight, also known as Grease Spot, is caused by several species of Pythium fungi. It is particularly severe in hot, humid weather and poorly drained soils.

Symptoms:

  • Greasy, dark, water-soaked patches that can spread rapidly.
  • Grass may feel slimy and collapse when touched.
  • White, cottony mycelium may be present in the early morning.

Prevention and Treatment:

  • Improve soil drainage and avoid excessive watering.
  • Increase air circulation by mowing properly and reducing thatch.
  • Apply fungicides preventively in areas with a history of Pythium Blight.

Rust

Description: Rust diseases are caused by several fungi, including Puccinia and Uromyces species. They occur in late summer to early fall when temperatures are mild.

Symptoms:

  • Grass blades turn yellow, orange, or brown and may be coated with a powdery rust.
  • Affected grass may become thin and weak.
  • Rust spores can rub off on shoes, mowing equipment, or fingers.

Prevention and Treatment:

  • Maintain a regular fertilization schedule to keep grass healthy.
  • Water early in the day to reduce leaf wetness.
  • Mow regularly and collect clippings to reduce spore spread.
  • Apply fungicides if the rust is severe.

Snow Mold

Description: Snow Mold, including Gray Snow Mold and Pink Snow Mold, appears after snow melts in late winter or early spring. Typhula and Microdochium fungi cause it.

Symptoms:

  • Circular patches of matted grass, ranging from a few inches to several feet in diameter.
  • Patches may have a white, gray, or pinkish mold on the surface.
  • Grass in affected areas is often dead or severely weakened.

Prevention and Treatment:

  • Avoid heavy nitrogen fertilization late in the fall.
  • Mow the lawn until growth stops in the fall to prevent matting.
  • Rake affected areas to encourage drying and grass recovery.
  • Use fungicides preventively in areas with a history of snow mold.

Fairy Ring

Description: Fairy Rings happen when soil fungi grow in circles, making rings or arcs in the lawn.

Symptoms:

  • Dark green rings or arcs of grass, sometimes with mushrooms or bare soil in the center.
  • The rings can range from a few inches to several feet in diameter.
  • The grass inside the ring may be lush or dead, depending on the fungus.

Prevention and Treatment:

  • Aerate the soil to improve water infiltration and reduce compaction.
  • Water deeply to promote uniform soil moisture.
  • Remove mushrooms to prevent spore spread.
  • Apply fungicides to control the fungus if necessary.

Knowing these common lawn diseases well helps you spot the signs early and take the right steps to keep your lawn healthy.

Prevention Tips for a Healthy Lawn

Maintaining a healthy lawn involves a combination of proper care practices. Here are some key tips on how to prevent lawn diseases:

Watering

  • Deep and Infrequent Watering: Water your lawn deeply but infrequently to encourage strong root growth. Aim to water in the early morning to allow grass to dry throughout the day.
  • Avoid Too Much Water: Too much water can create ideal conditions for fungal growth. Ensure your lawn gets about 1 to 1.5 inches of water per week, including rainfall.

Mowing

  • Proper Mowing Height: Keep your mower blades sharp and adjust the cutting height according to your grass type. Generally, keeping grass around 2.5 to 3.5 inches tall helps it stay healthy.
  • Mow Regularly: Avoid cutting more than one-third of the grass blade at a time. Regular mowing keeps grass strong and less prone to disease.

Fertilization

  • Balanced Fertilization: Use a balanced fertilizer and follow a regular schedule. Avoid over-fertilizing, which can lead to disease-prone, lush growth.
  • Seasonal Adjustments: Change your fertilization plan based on the season and your grass type to give the right nutrients at the right time.

Aeration

  • Regular Aeration: Aerate your lawn once or twice a year to improve soil drainage and reduce compaction. This helps roots grow deeper and stronger.
  • Reduce Thatch: Excessive thatch can harbor pests and diseases. Aeration helps break down thatch and promote healthy soil.

Seeding and Overseeding

  • Thick Turf: Keep your lawn thick and lush by seeding bare spots and overseeding thin areas. A dense lawn resists weeds and diseases better.
  • Proper Seed Selection: Choose disease-resistant grass varieties suited to your climate and soil conditions.

Weed Control

  • Regular Weed Management: Keep weeds in check with proper lawn care practices and herbicides if necessary. Weeds can compete with grass for nutrients and water, weakening your lawn.
  • Mulching: Use mulch around flower beds and trees to prevent weeds from spreading to your lawn.

Lawn Disease Prevention Strategies

  • Soil Testing: Test your soil every few years to determine its nutrient needs and pH level. Amend the soil as needed to maintain optimal conditions for grass growth.
  • Pest Management: Monitor your lawn for pests and treat infestations promptly. Healthy grass is more resistant to disease.
  • Proper Equipment Maintenance: Keep your lawn care equipment clean and well-maintained. Dirty equipment can spread diseases from one area of your lawn to another.

By following these prevention tips, you can maintain a healthy, disease-free lawn. Consistent care and attention to your lawn's needs will help ensure it stays green and beautiful throughout the year.

Identifying Lawn Diseases

Identifying lawn diseases early can help you take action before they spread and cause serious damage. Here are some tips and methods to help you diagnose common lawn diseases:

Visual Inspection

  • Discoloration: Look for unusual colors like yellow, brown, or black patches on your lawn.
  • Patterns: Note any circular, irregular, or ring-like patterns. Different diseases often have distinct shapes.
  • Growths: Check for visible mold, mildew, or mushrooms, which can indicate fungal infections.

Grass Blade Examination

  • Lesions: Examine individual grass blades for spots, streaks, or lesions. These can be signs of diseases like Dollar Spot or Leaf Spot.
  • Powdery Coating: Look for a powdery substance on grass blades, which is common with Rust diseases.

Texture and Feel

  • Slimy or Greasy Grass: Feel the affected areas. Slimy or greasy grass can indicate diseases like Pythium Blight.
  • Dry and Brittle Grass: Some diseases cause grass to become dry and brittle.

Environmental Conditions

  • Weather Patterns: Consider recent weather conditions. Many lawn diseases thrive in specific climates, such as hot and humid weather for Brown Patch or cool and wet conditions for Snow Mold.
  • Watering Practices: Reflect on your watering habits. Too much water or poor drainage can promote fungal growth.

Soil Health

  • Compaction and Thatch: Inspect your soil for compaction and thatch buildup. Compacted soil and excessive thatch can create environments conducive to disease.
  • Nutrient Deficiency: Test your soil to see if it lacks nutrients, which can make your lawn weak and more likely to get diseases.

By checking your lawn often and spotting these signs, you can quickly find and fix lawn diseases, keeping your grass healthy and green.

Treating Lawn Diseases

When it comes to treating lawn diseases, understanding the specific disease and its requirements for treatment is crucial. Here’s a comprehensive guide to effective treatments for common lawn diseases:

Brown Patch

  • Fungicides: Apply fungicides containing azoxystrobin, chlorothalonil, or thiophanate-methyl. Follow the instructions on the label for application rates and timing.
  • Cultural Practices: Reduce watering and only water in the early morning. Improve air circulation by reducing thatch and mowing at the recommended height.

Dollar Spot

  • Fungicides: Use fungicides such as propiconazole, flutolanil, or myclobutanil. Begin applications at the first sign of disease and repeat as necessary.
  • Nitrogen Management: Maintain adequate nitrogen levels through fertilization to reduce the risk of your lawn getting Dollar Spot.

Pythium Blight

  • Fungicides: Apply fungicides containing mefenoxam, propamocarb, or cyazofamid. Apply preventively during hot, humid weather if your lawn is prone to Pythium Blight.
  • Water Management: Improve drainage and avoid too much water. Water early in the day to allow grass to dry.

Rust

  • Fungicides: Use fungicides with active ingredients like myclobutanil, triadimefon, or azoxystrobin. Treat at the first sign of rust and repeat applications if necessary.
  • Cultural Practices: Mow regularly and collect clippings. Ensure proper fertilization to keep grass healthy and less susceptible to rust.

Snow Mold

  • Fungicides: Preventive applications of fungicides containing propiconazole, chlorothalonil, or fludioxonil before the first snowfall can help control snow mold.
  • Cultural Practices: Avoid heavy nitrogen fertilization late in the fall. Mow the lawn until growth stops to prevent matting. Rake affected areas in spring to promote drying.

Fairy Ring

  • Fungicides: Fungicides don't work well for fairy rings, but some with azoxystrobin or flutolanil can help.
  • Cultural Practices: Aerate the soil to improve water infiltration. Drench the rings with water and wetting agents to break up hydrophobic soil conditions.

Conclusion

Maintaining a Healthy Lawn Year-Round

A beautiful, green lawn is a source of pride for any homeowner. By knowing about common lawn diseases, how to find them, and how to stop and fix them, you can keep your lawn looking good all year.

Key Takeaways:

  • Identify Early: Regularly inspect your lawn for signs of disease to catch problems early and take prompt action.
  • Prevent Wisely: Water, mow, fertilize, and aerate your lawn properly to keep it healthy and avoid diseases.
  • Treat Effectively: Use appropriate fungicides and cultural practices to manage and eliminate lawn diseases when they occur.

Consistent care and attention to your lawn’s needs are essential. By applying the tips and strategies from this guide, you can enjoy a lush, green lawn that enhances the beauty of your home. Remember, a healthy lawn not only looks great but also contributes to a healthier environment. Happy lawn care!