A culinary bundle - grown together for the kitchen, with no interspecies claim made.
At least 1 m². A bed smaller than that does not get this guild quietly substituted for something else — the planner greys it out, says why, and offers the nearest adaptation that does fit.
Adapted from Pizza Garden.
Nothing is left living in the bed over winter; the whole planting is re-established.
No interspecies mechanism is claimed. It is grouped for a reason, and that reason is written below rather than dressed up as biology.
The pizza garden for a pot or sunny windowsill: a bush tomato, basil, and one pepper — all annuals. The cost is the perennial herbs (oregano, thyme, rosemary): they want permanent, unrotated ground and rosemary a mild zone, neither of which a replanted annual pot gives, so they are dropped. Still no interspecies mechanism — same bowl.
Rotation history attaches to the ground, not the bed, so this is what the planner remembers about this patch after the guild comes out.
There's no evidence for this and no mechanism anyone has proposed. Plant basil next to tomatoes anyway — you'll want them at the same time in the kitchen.
No proposed mechanism. No trials. Extremely widely believed.
Evidence: settled without a trial - definition.