Companion Planting Pairs

Every pairing below is labelled Good Match or Avoid, and every page behind that label names the actual mechanism - not just a verdict. We rate the evidence behind each pairing as evidence-backed, traditional lore, or mixed (see the Methodology page for exactly how that rating is decided), because a lot of companion-planting advice online blends tested agronomy together with folk sayings as if they carried equal weight.

The Two Kinds of Pairings

Beneficial pairings work through a small set of real mechanisms: one crop fixing nitrogen the other can use, a strong scent confusing a pest that hunts by smell, a sacrificial trap crop pulling pests away from the crop you actually want to protect, two root systems working different soil depths, one crop physically supporting another, or one simply providing useful shade. Antagonist pairings usually come down to direct competition for the same nutrients and water, a shared disease risk between related or vulnerable crops, or one crop chemically inhibiting the other's growth (a real, documented effect in a few specific cases, most notably fennel).

How to Use This List

If you already have two specific crops in mind, use the Companion Pairing Checker on the homepage for an instant answer - it reads the exact same underlying dataset as every page listed here, so the two can never quietly disagree. If you're planning from scratch, start from a crop's own growing guide instead, which lists its full set of confirmed companions and antagonists in one place, or use the Bed Layout Helper to lay out an entire bed at once while honoring these relationships automatically.

Not every crop combination has a documented relationship in either direction - most pairs of unrelated crops are simply neutral, and we don't manufacture a verdict where none genuinely exists.

Essential Pairs vs. Quick-Reference Pairs

The most commonly asked-about pairings on this site get a full write-up covering the mechanism, the evidence, spacing, and what to watch for in depth. Less-searched pairings still carry the same required mechanism and evidence-rating fields - the honesty label is never skipped - but with a shorter framing paragraph and a link to the relevant crop guides for the surrounding growing detail, rather than a full standalone essay repeating information that already lives on each crop's own page.

Good Match vs. Avoid, at a Glance

A Good Match label means the pairing has a real, named mechanism working in its favor - even if the evidence behind that mechanism is only traditional lore rather than confirmed. An Avoid label means there's a specific, named reason to keep the two crops apart - competition for the same nutrients, a shared vulnerability to the same disease, or a documented growth-inhibiting chemical effect. Neither label is a guess dressed up as a verdict; both point to a stated reason you can evaluate for yourself.