Why Are My Swiss Chard Leaves Turning Brown? Troubleshooting Tips

Swiss chard is a popular leafy green known for its colorful stems and healthy nutrient profile. However, you may notice your chard leaves turning brown during the growing season. Brown leaves on chard are usually a sign of stress or disease. Don’t despair – there are several common causes of brown leaves on Swiss chard and ways you can troubleshoot to prevent it from happening again.

Common Causes of Brown Leaves on Swiss Chard

Here are some of the most common reasons for Swiss chard leaves turning brown

Environmental Stress

Fluctuations in temperature, overly wet or dry soil, and lack of nutrients can stress chard and cause the leaves to brown. Swiss chard prefers cool weather and consistent moisture. Make sure to provide chard with 1-2 inches of water per week if rain is lacking. Extreme heat can also scorch the leaves.

Diseases

• Bacterial soft rot – Caused by bacteria, leaves develop water-soaked lesions and rotting. Promoted by wet conditions.

• Cercospora leaf spot – Fungal disease that begins with small gray/brown spots that grow and merge. Humid environments encourage spread.

• Downy mildew – Another fungal disease that coats leaves with gray fuzz and makes them twist and distort,

• Powdery mildew – Leaves develop white fungal patches that can spread. Another disease worsened by humidity.

Insect Pests

• Leafminers – Small flies or beetles that bore into leaves and create winding tunnels. This damages the leaves.

• Flea beetles – Tiny black beetles that chew tiny holes in foliage. Can quickly shred leaves.

• Caterpillars – Worms like cabbage loopers eat through leaves leaving behind lots of damage.

Nutrient Deficiencies

Lack of nutrients like nitrogen, phosphorus, or magnesium can cause chard leaves to yellow or brown. Test soil and amend accordingly.

What to Do About Brown Leaves on Chard

If your Swiss chard leaves are turning brown, take these steps to remedy the issue:

• Remove any heavily damaged or diseased leaves promptly. This prevents spread.

• Check soil moisture and water if dry. Chard needs consistent moisture.

• Apply mulch to maintain soil moisture and temperature.

• Scout for pests like caterpillars and flea beetles. Remove by hand or use organic sprays if needed.

• Treat fungal diseases with organic fungicides containing neem oil or copper sulfate.

• Test soil and amend with compost or fertilizer to provide nutrients if deficient.

• Use row covers or shade cloth if heat stress is the issue.

How to Prevent Brown Leaves on Swiss Chard

Practicing prevention is key to keep your Swiss chard leaves healthy and avoid browning. Here are some tips:

• Choose disease-resistant varieties when possible.

• Rotate planting location each year to prevent disease buildup in soil.

• Water at the base of plants to keep foliage dry.

• Allow for good airflow and space plants adequately.

• Use floating row covers to exclude pests.

• Apply compost and fertilizer to ensure nutrients are available.

• Check soil drainage and improve if needed.

• Use drip irrigation and mulch for consistent moisture.

• Monitor for pests and remove early before they spread.

• Remove and destroy diseased plants promptly.

What If My Whole Swiss Chard Plant is Brown?

If your Swiss chard plant has turned entirely brown and died, it is unfortunately time to pull it out. Diseases like beet curly top virus or severe pest damage can kill the whole plant quickly. Clear out dead plants right away to prevent issues from impacting the rest of the garden.

Focus on planting disease-free seed in new soil next time around. And be vigilant about scouting for pests and disease symptoms early so you can take action before losing the whole plant. With quick troubleshooting, you can keep your Swiss chard thriving!