Tomato Blight: 15 Days of Rain
Tomatoes are a beloved garden staple, but they’re also one of the most vulnerable crops when it comes to disease—especially during extended periods of wet weather. After 15 days of continuous rain, your once-thriving tomato plants may begin to show troubling signs: dark spots, yellowing leaves, and withering stems. These are the hallmarks of tomato blight, a fast-spreading fungal disease that can wipe out an entire harvest if not managed quickly.
What is Tomato Blight?
Tomato blight is a general term that covers two main types of fungal diseases: early blight and late blight. Both are caused by different pathogens but thrive in similar conditions—prolonged moisture, poor air circulation, and wet leaves. After 15 consecutive days of rain, your garden becomes the perfect breeding ground for these destructive fungi.
- Early Blight (caused by Alternaria solani) usually starts with concentric ring patterns on the older leaves and works its way up.
- Late Blight (caused by Phytophthora infestans) is more aggressive, causing dark, greasy-looking patches on leaves, stems, and eventually the fruit itself.
Both types of blight can decimate plants rapidly in wet conditions.
How Rain Sets the Stage for Blight
Rain creates a damp environment that is ideal for fungal spores to germinate and spread. Here’s how 15 straight days of rain contribute to the problem:
- Constant Leaf Moisture: Wet leaves give fungal spores the surface they need to stick, germinate, and infect plant tissues.
- Soil Splash: Rain can splash soil particles—along with fungal spores—onto the lower leaves of plants, initiating infection.
- Poor Air Circulation: Overcast and humid conditions reduce evaporation, causing leaves to stay wet longer.
- Stress on Plants: Too much water can weaken plant immunity, making them more susceptible to disease.
Signs to Watch For
After heavy rains, inspect your tomato plants closely. Watch for:
- Brown or black spots on leaves and stems
- Yellowing leaves, especially starting from the bottom up
- A foul smell around the plants
- Rapid leaf drop
- Discoloration or soft rot on developing fruit
Early detection is key to containing the spread.
What You Can Do Now
If you suspect blight after extended rain, take immediate action:
- Remove Affected Leaves: Cut off infected leaves and dispose of them—don’t compost! Fungal spores can survive and re-infect.
- Improve Airflow: Prune excess foliage to increase air circulation. This helps leaves dry more quickly after rain.
- Apply a Fungicide: Organic options like copper-based sprays or neem oil can slow the spread. Apply in dry breaks between rains.
- Mulch and Stake: Keep fruit and lower leaves away from wet soil by staking and adding mulch.
- Avoid Overhead Watering: Use drip irrigation or water at the base to keep foliage dry.
Long-Term Prevention
- Rotate Crops: Avoid planting tomatoes in the same spot year after year.
- Choose Resistant Varieties: Some tomato cultivars are bred to resist blight.
- Clean Up at Season’s End: Remove all plant debris to prevent overwintering spores.
Final Thoughts
Fifteen days of rain is a perfect storm for tomato blight, but with careful observation and swift action, your plants may still recover. Gardening is often about adapting to nature’s surprises, and by staying vigilant, you can weather even the soggiest growing season with a few tomatoes to show for it.
