Tomato + Sweet Corn

Tomato and corn are a poor pairing in the vegetable garden, primarily because they share the corn earworm (Helicoverpa zea), which goes by the name tomato fruitworm when it attacks tomatoes. A moth that lays eggs on corn silk in midsummer will readily shift to nearby tomato flowers and developing fruit. The practical minimum separation is 30 feet; more is better where garden layout allows.

Soil and timing overlap compound the problem. Both crops are heavy nitrogen feeders that compete for the same nutrients at peak season, and corn's height can shade tomatoes planted to the south or west. Corn smut (Ustilago maydis) shares some hosts with solanums, adding a secondary disease concern in humid climates.

No benefit commonly attributed to this combination outweighs the pest pressure risk. Where space is limited, treat these crops as incompatible and plan separate beds on opposite ends of the garden.