My Tomatoes Are Dying & Have Rust on the Leaves

Rust Mites

• Rust mites are tiny, yellow, wormlike pests that are almost impossible to see with the naked eye. The damage it inflicts on tomato plants identifies it. They first feed on the lower leaves, which causes rust-colored spots. Treat the plant immediately with a commercial product that targets rust mites. If left untreated, the mites work their way up the stem and crack it. They then feed on the upper leaves, which cause the plant to die. Plant your tomato plants with plenty of space between them. This discourages mites.

Early Blight

• The fungal disease, called early blight, Alternaria or target spot, is common wherever tomatoes are grown. A pathogen called Alternaria solani causes it. The fungus forms dark rings on the leaves. The surrounding area turns yellow, and then turns rust or brown. The foliage is eventually destroyed. The spores spread by the wind, rain and insects. Potatoes also host the spores. Treat the plant with appropriate commercial fungicides.

Anthracnose

• A common fungus that attacks tomatoes is Colletotrichum coccodes, or anthracnose. It attacks the fruit, causing an indented circle on the skin. The spot develops a dark-brown center with a ring around it, which is the spore-producing body. The circle turn a salmon or light rust. The fruit then rots. Rain, birds and seeds spread the fungus. It survives on diseased vines through the winter and can infect new plants the following season. Harvesting all ripe fruit at regular intervals helps prevent this disease. Treat the disease with commercially available fungicides as soon as it's detected.

Powdery Mildew

• The scientific name for powdery mildew is Oidium neolycopersici. It attacks tomato plants when there is poor air circulation and humid conditions. The leaves initially develop white, powdery spots that turn rust before the leaf dies. Commercial fungicides control the fungus. Spacing your plants well helps prevent this condition. If your tomatoes are in a greenhouse, improve air circulation.