Companion planting guide › Tomato and basil

Tomato and basil: does it work?

Folklore-unproven Popular claim without supporting field evidence, or tested and not supported.

Double-blind taste tests found no consistent flavor benefit. Yield and pest results from the only garden-scale study are mixed.

1. Bomford M.K. (2004). Yield, pest density, and tomato flavor effects of companion planting in garden-scale studies incorporating tomato, basil, and Brussels sprout. West Virginia University dissertation.
2. Bomford M.K., Butler L. Do Tomatoes Love Basil But Hate Brussels Sprouts? ASA–CSSA–SSSA meeting abstract (2003).

Mechanism

Claimed: basil improves flavor and repels pests. Tested: competition for light and water drove most effects.

What the research found

• WVU garden-scale studies (2000–2003): no consistent taste preference for tomatoes grown with companions (Bomford 2004).
• Relative-yield indices showed a mean ~20% advantage when tomato was paired with basil at high densities (dissertation abstract), while the meeting abstract reported no Land Equivalency Ratio significantly greater than one.
• Insect pests on tomato did not respond to companion planting (Bomford & Butler abstract).

Caveats

One research program, one region. Pairing is harmless and both are useful, but don't expect better taste or pest control.