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Signet Marigold Companion Planting

Tagetes tenuifolia

Daisy (Asteraceae) -- warm season

2 beneficial companions
0 antagonistic relationships

Good Companions for Signet Marigold

TomatoSolanum lycopersicum
BeneficialPest SuppressionDocumented

French marigold (Tagetes patula) root exudates contain alpha-terthienyl, a nematicide that suppresses root-knot nematodes (Meloidogyne spp.). This effect requires marigolds to be grown for a full season in the same soil.

French marigolds (Tagetes patula) are more effective than African marigolds (T. erecta) for nematode suppression. Grow for a full season before planting tomatoes in the same bed.

Sources
  • Suppressive effect of Tagetes spp. on Meloidogyne species -- Nematropica (2000)
  • Managing nematodes with marigolds -- UC IPM Pest Management Guidelines (2018)
  • Marigolds (Tagetes spp.) for nematode management -- University of Florida IFAS Extension (2019)
Bush BeanPhaseolus vulgaris
BeneficialPest SuppressionSupported

Marigold (Tagetes spp.) roots suppress root-knot nematodes (Meloidogyne spp.) that damage bean root systems. Marigold flowers also attract hover flies and predatory insects.

Interplant French marigolds among bush beans or use marigolds in rotation before beans.

Sources
  • Suppressive effect of Tagetes spp. on Meloidogyne species -- Nematropica (2000)