Can I plant marigold next to tomato?

Yes. UF/IFAS Extension confirms French marigold is effective against a wide range of root-knot nematode species — a real, documented effect, not folklore. The insect-pest-deterrent half of this claim is less well documented.

Can I plant marigold next to zucchini?

Yes. An Iowa State study found marigold (alongside nasturtium) reduced squash bug and cucumber beetle damage when planted near squash, a real trap-crop/deterrent effect rather than folklore.

Companion Planting: Marigold

Tagetes

Spacing: 4 per square foot. Mature height: 0.5-1 ft.

Plant these nearby

Tomato: UF/IFAS Extension confirms French marigold is effective against a wide range of root-knot nematode species — a real, documented effect, not folklore. The insect-pest-deterrent half of this claim is less well documented. (source)
Zucchini: An Iowa State study found marigold (alongside nasturtium) reduced squash bug and cucumber beetle damage when planted near squash, a real trap-crop/deterrent effect rather than folklore. (source)

Keep these apart

No known antagonists recorded for Marigold.

Common pairings, answered directly

Can I plant marigold next to tomato?: Yes. UF/IFAS Extension confirms French marigold is effective against a wide range of root-knot nematode species — a real, documented effect, not folklore. The insect-pest-deterrent half of this claim is less well documented.
Can I plant marigold next to zucchini?: Yes. An Iowa State study found marigold (alongside nasturtium) reduced squash bug and cucumber beetle damage when planted near squash, a real trap-crop/deterrent effect rather than folklore.

Lay this out in the Garden Designer →

Pin this for later

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

Save to Pinterest