Tomato plants require a great deal of water to grow properly. When a tomato plant is approximately 2 to 3 feet tall, the dense growth creates a shady, moist canopy between the soil and the lower branches. This is the ideal breeding ground for mosquitoes. To keep mosquitoes away from tomato plants, it is not necessary to spray the plant with toxic chemicals. Use natural mosquito repellents instead.
Purchase mosquito-repelling plants. Marigolds add bright color to the garden. Basil and garlic both add depth of flavor to developing tomatoes. Choose one that suits the needs of your household.
Dig a ring around your tomato plant, approximately 4 to 6 inches further out than the furthest-reaching branch of the tomato plant. Break up the soil in the ring to approximately 4 inches deep.
Plant the mosquito-repelling seedlings into the ring. Space them as close together as possible, to create a strong repellent barrier. Brush the soil back over the plants' root balls and into remaining spaces in the ring.
Water thoroughly, to enable the root systems to settle and release any trapped oxygen bubbles. Thereafter, water as you would regularly water your tomato plants.