Can I plant carrot next to onion?

Yes. A real, peer-reviewed field study (Uvah & Coaker 1984) found intercropping onions with carrots reduced carrot rust fly damage, on the theory that mixed scents mask the host plant from pests hunting by smell.

Can I plant carrot next to tomato?

Yes. Carrots aerate soil around tomato roots.

Can I plant carrot next to dill?

Better not to. Reputed to inhibit carrot root development once dill matures, but no research was found testing this specific pairing — the only related study tested dill's allelopathic effect on tomato germination, not carrot. Treat this as garden tradition, not measured evidence.

Companion Planting: Carrot

Daucus carota

Spacing: 16 per square foot. Mature height: 0.5-1 ft.

Plant these nearby

Onion: A real, peer-reviewed field study (Uvah & Coaker 1984) found intercropping onions with carrots reduced carrot rust fly damage, on the theory that mixed scents mask the host plant from pests hunting by smell. (source)
Tomato: Carrots aerate soil around tomato roots.

Keep these apart

Dill: Reputed to inhibit carrot root development once dill matures, but no research was found testing this specific pairing — the only related study tested dill's allelopathic effect on tomato germination, not carrot. Treat this as garden tradition, not measured evidence.

Common pairings, answered directly

Can I plant carrot next to onion?: Yes. A real, peer-reviewed field study (Uvah & Coaker 1984) found intercropping onions with carrots reduced carrot rust fly damage, on the theory that mixed scents mask the host plant from pests hunting by smell.
Can I plant carrot next to tomato?: Yes. Carrots aerate soil around tomato roots.
Can I plant carrot next to dill?: Better not to. Reputed to inhibit carrot root development once dill matures, but no research was found testing this specific pairing — the only related study tested dill's allelopathic effect on tomato germination, not carrot. Treat this as garden tradition, not measured evidence.

Lay this out in the Garden Designer →

Pin this for later

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

Save to Pinterest