Black Spots on Tomato Plant Leaves & Stems

Tomato plants should have solid green leaves and stems.

Healthy tomato plants have leaves and stems that are a dull green. Black spots appearing on the tomato plant's stem and leaves are a sign of a fungal disease known as early blight and, if left untreated, it can lead to severe consequences for the plant.

Symptoms

Early blight in tomatoes causes small irregular black or brown spots on the leaves of tomatoes which grow larger and develop a yellow halo. Black spots on the stem are small and black with a slight sunken look and they elongate over time.

Solution

Examine your tomato plants frequently to ensure that the stems and leaves as well as the fruit are free of spots and stains. Apply a standard fungicide when you find signs of early blight. Early diagnosis leads to healthier plants.

Prevention

Plant varieties like Plum Dandy and Mountain Supreme, which are resistant to early blight. Give tomato plants plenty of room, to promote air circulation, which cuts down on fungal infection.

References

• Colorado State University: Recognizing Tomato Problems
• Virginia Cooperative Extension: Early Blight of Tomatos