Why Is My Grass Turning White?

White grass can be a cause for concern for homeowners who take pride in maintaining a healthy, green lawn. In this comprehensive guide, we will explore the possible causes of white grass, as well as preventative measures and treatment options to restore your lawn to its original, lush state.

Possible causes of white grass

Fungal diseases

1. Powdery mildew

• Description of the disease: Powdery mildew is a common fungal disease that affects various plants, including grass. It is characterized by a white, powdery substance on the grass blades.
• Conditions favoring its development: This disease thrives in cool, damp, and shady conditions.
• Symptoms and signs: Affected grass will have a white, powdery appearance, and may become stunted, yellow, or even die.
• Prevention and treatment methods:
  • Increase air circulation and sunlight exposure
  • Water the lawn in the morning to allow time for drying
  • Apply fungicides if necessary

2. Pythium blight

• Description of the disease: Pythium blight, also known as “grease spot,” is a fungal disease that causes rapid turfgrass death.
• Conditions favoring its development: This disease thrives in hot, humid conditions, and is especially prevalent in areas with poor drainage.
• Symptoms and signs: Initial symptoms include small, water-soaked spots that may later turn white, gray, or brown as the grass dies.
• Prevention and treatment methods:
  • Improve drainage in the affected area
  • Avoid excessive nitrogen fertilization
  • Apply fungicides if necessary

Pests

1. White grubs

• Description of the pest: White grubs are the larval stage of various beetles, including Japanese beetles and June beetles. They feed on grass roots, causing the grass to turn white and die.
• Life cycle and damage: White grubs have a one-year life cycle. They lay eggs in the soil, which hatch into larvae that feed on grass roots. The damage is most severe in late summer and early fall.
• Symptoms and signs: Affected grass will appear white, wilted, and easily pulled up from the soil.
• Prevention and treatment methods:
  • Apply insecticides if grub populations are high
  • Encourage natural predators, such as birds and beneficial insects
  • Maintain proper lawn care practices to promote healthy grass

2. Chinch bugs

• Description of the pest: Chinch bugs are small, black insects that feed on grass sap, causing the grass to turn white and die.
• Life cycle and damage: Chinch bugs have multiple generations per year and are most active during hot, dry weather.
• Symptoms and signs: Affected grass will exhibit irregular patches of white, dead grass.
• Prevention and treatment methods:
  • Apply insecticides if chinch bug populations are high
  • Encourage natural predators, such as spiders and predatory insects
  • Water deeply and infrequently to promote healthy grass roots

Environmental factors

1. Sun bleaching

• Causes of sun bleaching: Sun bleaching occurs when grass is exposed to intense sunlight, causing the chlorophyll to break down and the grass to turn white.
• Symptoms and signs: Affected grass will appear white or yellow, particularly in areas with direct sunlight exposure.
• Prevention and treatment methods:
  • Provide shade to the affected area if possible
  • Water deeply and infrequently to promote healthy grass roots

2. Salt damage

• Causes of salt damage: Salt damage can occur from de-icing salts used during the winter months or salt spray from coastal areas. Salt can cause grass to lose moisture, leading to a white appearance.
• Symptoms and signs: Affected grass will appear white, yellow, or brown, and may be more pronounced along walkways or driveways where salt has been applied.
• Prevention and treatment methods:
  • Use alternative de-icing methods or more environmentally-friendly products
  • Flush the affected area with water to remove excess salt
  • Apply gypsum to help counteract the effects of salt

3. Drought stress

• Causes of drought stress: Prolonged periods of dry weather can cause grass to become stressed, leading to a white or brown appearance.
• Symptoms and signs: Affected grass will appear white, brown, or wilted, and may be more pronounced in areas with full sun exposure.
• Prevention and treatment methods:
  • Water deeply and infrequently to promote healthy grass roots
  • Apply a layer of mulch to help retain moisture
  • Choose drought-tolerant grass species for your lawn

Proper lawn care and maintenance

Watering

• Importance of proper watering: Adequate watering is crucial for maintaining a healthy lawn and preventing white grass issues.
• Best practices for watering:
  • Water deeply (6 to 8 inches) and infrequently (1 to 1.5 inches per week)
  • Water in the early morning to minimize evaporation and fungal diseases
  • Use a rain gauge or a small container to measure the amount of water applied

Fertilization

• Importance of proper fertilization: A well-fertilized lawn will be more resistant to pests, diseases, and environmental stresses that can cause white grass.
• Best practices for fertilization:
  • Apply the right type and amount of fertilizer based on soil test results
  • Follow a regular fertilization schedule, typically every 6 to 8 weeks during the growing season
  • Use a slow-release fertilizer to minimize nutrient runoff and leaching

Mowing

• Importance of proper mowing: Regular mowing helps maintain a dense, healthy turf that can better resist pests, diseases, and environmental stress.
• Best practices for mowing:
  • Mow at the recommended height for your grass species (typically 2.5 to 4 inches)
  • Keep mower blades sharp to prevent tearing the grass blades
  • Mow when the grass is dry to prevent clumping and the spread of diseases

Aeration and dethatching

• Importance of aeration and dethatching: Aeration and dethatching improve soil and root health, promoting a more robust and resilient lawn.
• Best practices for aeration and dethatching:
  • Aerate the lawn at least once a year, ideally in the fall
  • Dethatch the lawn when thatch buildup exceeds 0.5 inches
  • Use a core aerator or a dethatching rake for best results

Seeking professional help

When to call a professional

It may be necessary to seek professional help if:

• Your lawn problems persist despite your best efforts
• You are unsure of the cause of your white grass
• The issue appears to be beyond your expertise or capabilities

Types of professionals

1. Lawn care specialists: Experts in maintaining healthy lawns and treating common problems
2. Arborists: Professionals trained in the care and maintenance of trees and shrubs
3. Pest control experts: Specialists in identifying and treating lawn pests and infestations

Evaluating professional services

• Ask for recommendations from friends, neighbors, or local gardening clubs
• Research online reviews and testimonials
• Request quotes from multiple companies for comparison
• Ensure the company is licensed, insured, and has relevant certifications
• Ask about their treatment methods, products used, and any guarantees they offer

Conclusion

Understanding the various causes of white grass, from fungal diseases and pests to environmental factors, is essential in maintaining a healthy, green lawn. Implementing proper lawn care practices, such as adequate watering, fertilization, mowing, and aeration, can prevent many of the issues that lead to white grass.

However, when problems persist despite your best efforts, seeking professional help may be necessary. With the right approach, your lawn can be restored to its original, lush state, providing an inviting outdoor space for you and your family to enjoy.