Asteraceae — Daisy family

Shared risks

• lettuce downy mildew
• aphids
• slugs on lettuce

Named risks, not an arbitrary score: these are the organisms that carry over in soil, debris or volunteers.

Rotation guidance

Leave 1 year before returning any daisy family member to the same bed. Rotation concerns previous seasons in a bed; it is separate from which plants grow together now.

• Marigold nematode suppression is a soil effect from a dense stand, not a neighbour effect.

Sources

• Using marigold (Tagetes spp.) as a cover crop to protect crops from plant-parasitic nematodes (2010)
• Agronomy of strip intercropping broccoli with alyssum for biological control of aphids (2016)

Exceptions and small-garden notes

Short crops (radish, arugula, baby leaves) still count as occupancy for the family. In a garden with one or two beds, strict rotation is impossible; instead, alternate families within a bed by half, remove crop debris, choose resistant cultivars and keep a bed history so the planner can warn you.

Other families: Solanaceae · Brassicaceae · Fabaceae · Cucurbitaceae · Apiaceae · Amaryllidaceae · Lamiaceae · Amaranthaceae · Poaceae · Rosaceae · Other families