Overview

Cup Plant (Silphium perfoliatum) is a bold, tall native with perfoliate leaves that form water holding cups and sunny yellow daisies from midsummer into fall. It excels in full sun and medium to wet soils, builds deep roots, and offers exceptional wildlife value along with dramatic scale for spacious plantings.

Why You’ll Love It

• Low-maintenance: vigorous in sun with consistent moisture

• Wildlife magnet: flowers feed pollinators and leaf cups hold water for birds and insects

• Big impact: towering stems and broad leaves create a prairie backdrop

Ideal Site & Soil

• Sun first: 6 or more hours of direct light for sturdy stems

• Moisture matters: prefers medium to wet soils and tolerates clay that is not stagnant

• Space to thrive: allow room for height and spread in small gardens

Planting Steps

• From pots or divisions: set crown at soil line, water to settle, space 30 to 48 inches

• From seed: fall sow or spring sow after cold stratification, keep evenly moist until established

• Mulch: thin, airy layer helps retain moisture and suppress weeds

Care Routine

• Watering: maintain even moisture the first year, then water in droughts

• Feeding: avoid high nitrogen that pushes soft, tall growth

• Editing: deadhead to limit self seeding in tight spaces or leave seed for birds

• Staking: rarely needed in full sun and average fertility

Design & Companions

• Moist meadow mix: Joe Pye Weed, Blue Vervain, Great Blue Lobelia

• Tall prairie frame: Switchgrass, Indian Grass, New England Aster

• Rain garden basins: site on deeper shelves for summer moisture

Common Mistakes

• Planting in small beds: scale can overwhelm tight spaces

• Too little sun: taller, looser stems with fewer flowers

• Letting all seed mature: rapid spread where not desired

Quick Troubleshooting

• Leaning stems: increase sun and reduce fertility

• Few flowers: ensure full sun and steady moisture through bud set

• Unwanted seedlings: deadhead most heads before seed drop

Where It Fits Best

Rain gardens, swales, pond edges, and large prairie-style borders where tall wildlife habitat, soil holding, and a dramatic summer show are welcome.