Silphium perfoliatum (Cup Plant)

Silphium perfoliatum, commonly known as Cup Plant, is a tall, clump-forming perennial native to North America. It is named for its large, square stems and opposite, perfoliate leaves that join at the stem to form a "cup" capable of holding water, providing a habitat for birds and insects. The plant produces bright yellow, daisy-like flowers with a golden center, arranged in loose clusters at the top of the stems. Its height and unique leaf structure make it an excellent choice for naturalistic gardens, prairies, or pollinator-friendly landscapes.

Silphium perfoliatum thrives in moist, well-drained soils but can tolerate clay or wet conditions, making it suitable for rain gardens or areas near ponds or streams. It is drought-tolerant once established and attracts bees, butterflies, and birds, making it a valuable addition to wildlife-friendly gardens. The plant is resistant to deer and rabbits, making it a low-maintenance choice for naturalistic plantings. Deadheading can prolong blooming, and cutting back in late fall or early spring prepares the plant for the next growing season. Pair it with other tall prairie plants like Joe Pye weed (Eutrochium), blazing star (Liatris), and ornamental grasses for a dynamic, layered effect.

Sun Requirements:

Full Sun to Partial Shade. Prefers full sun for robust growth and abundant flowering but tolerates partial shade, particularly in hotter climates.

Maximum Growth Height:

6–10 feet (180–300 cm), with a spread of about 3–4 feet (90–120 cm), making it a standout plant in any garden.

Bloom Month:

July to September. Blooms in mid to late summer, providing long-lasting flowers that attract pollinators.