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Cup plant

Silphium perfoliatum

SILL-fee-um per-fo-lee-AY-tum

A coarse but bold perennial giant for the back of the border with yellow, daisy-like flowers in summer. Cups form where the toothed leaves meet the thick stems; birds are said to drink from the water held in the cups. Tough prairie natives that will self-sow, these plants need lots of sun and lots of room—a single plant can reach 7 or 8 feet tall and 6 feet across.

CareProvide moist, moderately rich, well-drained, neutral to alkaline soil for best results, but plants are fairly adaptable.

PropagationSow ripe seeds. Divide in spring.

ProblemsDowny mildew, rust.

  • Genus : Silphium
  • Plant Width : 3 to 6 feet
  • Zones : 5, 6, 7, 8, 9
  • Plant Height : 6 to 10 feet
  • Bloom Time : Early Fall, Late Summer, Summer
  • Growth Rate : Fast
  • Light : Full Sun to Partial Shade
  • Moisture : Medium to Wet
  • Maintenance : Moderate
  • Plant Type : Perennials
  • Characteristics : Self Seeds
  • Plant Seasonal Interest : Summer Interest
  • Flower Color : Yellow

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