Tomato Blight: A Crunchy Moon Guide to Prevention and Control

Tomatoes are a summer garden favorite, but one problem can ruin your harvest: blight. This fungal disease comes in two main forms - early blight and late blight - and both can quickly destroy your plants if not managed properly. Understanding, preventing, and acting quickly is key.

Types of Tomato Blight

• Early Blight (Alternaria solani):

  • Appears as small, dark spots with concentric rings on older leaves.
  • Usually attacks leaves first, then stems and fruit.
  • Favored by warm, humid conditions.

• Late Blight (Phytophthora infestans):

• Causes dark, greasy-looking spots on leaves and stems.
• Can rapidly spread to fruit, causing brown, rotten patches.
• Thrives in cool, wet weather.

Recognizing Blight

• Leaves: Yellowing, brown spots, or curling.
• Stems: Dark lesions or black streaks.
• Fruit: Discolored patches or rotting spots.
• Rapid Spread: Late blight can destroy an entire plant in days under wet conditions.

Prevention Strategies

• Resistant Varieties: Choose tomato cultivars labeled as blight-resistant.
• Crop Rotation: Don’t plant tomatoes or other nightshades (potatoes, peppers, eggplants) in the same soil two years in a row.
• Proper Spacing: Give plants 24–36 inches between rows for airflow.
• Mulch: Apply straw or shredded leaves to prevent soil-borne spores from splashing onto leaves.
• Water Wisely: Water at the base of plants, not overhead. Early morning watering is best.
• Sanitation: Remove infected leaves promptly. Don’t compost heavily infected material unless you hot-compost.
• Pruning: Keep lower leaves off the ground and remove dense foliage to improve airflow.

Organic Control Options

• Copper Fungicide: Can prevent spread of early and late blight. Follow label instructions carefully.
• Baking Soda Spray: Mix 1 tablespoon baking soda, 1 teaspoon liquid soap, and 1 quart water. Spray affected leaves weekly.
• Neem Oil: Effective against fungal spores; apply weekly or after heavy rains.
• Compost Tea: Spraying well-brewed compost tea can strengthen leaf resilience.

What to Do If Your Plant Gets Blight

1. Isolate: If potted, move infected plants away from healthy ones.
2. Prune Carefully: Cut off infected leaves and stems, burn or dispose of them safely.
3. Monitor: Check remaining plants daily for signs of spread.
4. Fungicide Application: Use organic fungicides immediately. Floow directions on any product you use.
5. Harvest Quickly: If fruit is developing, pick ripe or nearly ripe fruit before infection spreads.

Tips for Tomato Blight Management

• 🌞 Sun & airflow: Plant tomatoes in full sun with good spacing for disease resistance.
• 🪴 Rotation magic: Rotate crops every year to prevent fungal buildup.
• 🌱 Water smart: Avoid wetting leaves. Drip irrigation or soaker hoses are ideal.
• 🍅 Early harvest: Pick fruit as soon as it ripens to reduce risk of late-season infection.
• 🌿 Resistant companions: Basil, marigolds, and borage may help reduce fungal pressure.

⚠ Cautions

• Fungicide overuse: Even organic fungicides can accumulate and harm soil life if over-applied!
• High humidity: Tomato blight spreads fastest in wet, humid conditions - watch weather patterns.
• Sanitation lapses: Leaving infected leaves in the garden can restart blight next season.
• Cross-contamination: Clean tools after pruning or handling infected plants to avoid spreading spores.

Blight is one of those garden frustrations that can take you by surprise. But with smart planting, vigilant care, and quick action at the first sign of trouble, you can keep your tomatoes healthy and productive. Prevention is always better than cure - and a little vigilance will save you a lot of heartache when harvest time comes.