How Close Do I Plant Basil to Tomatoes?

Benefits

• Companion planting is the process of planting species that encourage one another's growth close together. Sweet basil planted near tomatoes improves flavor and plant growth, according to most sources. This plant may also discourage flying pests. Avoid planting these species near dill, rue, corn, fennel, potatoes and cabbages and their relatives, since these plants may use up vital nutrients or stunt their growth.

Tomato Spacing

• Tomato plants require careful spacing and staking to grow healthy stems and foliage, as well as to produce a quality crop. The appropriate distance between tomato plants or between tomatoes and other plants depends on the variety. Most home garden tomatoes should be planted 24 to 36 inches apart, with large vine species planted at least 36 inches apart. Ideally, keep rows 4 to 5 feet apart to discourage outbreaks of fungal disease.

Basil Spacing

• Basil plants can grow to be very tall and bushy, given ideal growing conditions. These plants should be placed 24 inches apart in the row, with 3 feet between rows. As with tomatoes, placing basil too close to other plants can prevent the foliage from drying properly, encouraging fungal conditions to flourish. Pinch the terminal growth periodically to encourage bushy, dense basil, rather than spindly growth that interferes with other plants.

Spacing as Companion Plants

• Planting basil and tomatoes as companion plants can affect their spacing distances. According to the Kentucky State University Organic Agriculture Working Group, planting companion plants in a hexagonal grid allows gardeners to produce more plants in a smaller area. The KSUOAW's spacing calculator suggests planting a mixed basil and tomato crop between 17 and 19 inches apart, to maximize yield per square foot.

Cultural Requirements

• Both tomato and basil plants require periodic fertilizer application, but not too much. Excessive nitrogen can encourage tomato plants to grow mostly lush stems and leaves, but not much fruit. Basil should receive only light fertilizer application, since too-rapid growth produces large quantities of low-flavor leaves. Tomatoes require fairly large quantities of water; about 1 to 2 inches per week. Basil needs somewhat less water, and can suffer from problems if the roots become waterlogged. When planting these species together, use well-drained soil and water plants individually.