Companion Planting: Cauliflower

Brassica oleracea

Spacing: 1 per square foot. Mature height: 1.5-2 ft.

Plant these nearby

• Onion: Onion scent is reputed to confuse cabbage moths that target brassicas. The research behind this is real but garlic-specific (field trials intercropping garlic with cabbage reduced diamondback moth damage) — onion hasn't been tested the same way, so treat the onion version as a reasonable extrapolation, not a directly measured result.

Keep these apart

• Tomato: Widely repeated that brassicas and tomatoes compete heavily and can stunt each other, but no extension or research source was found testing this specific claim — treat it as garden tradition, not measured evidence.

Common pairings, answered directly

Can I plant cauliflower next to onion?

Yes. Onion scent is reputed to confuse cabbage moths that target brassicas. The research behind this is real but garlic-specific (field trials intercropping garlic with cabbage reduced diamondback moth damage) — onion hasn't been tested the same way, so treat the onion version as a reasonable extrapolation, not a directly measured result.

Can I plant cauliflower next to tomato?

Better not to. Widely repeated that brassicas and tomatoes compete heavily and can stunt each other, but no extension or research source was found testing this specific claim — treat it as garden tradition, not measured evidence.

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Companion planting for Cauliflower: which plants to grow next to it, which to keep apart, and the reason behind each pairing.

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