Silphium perfoliatum (Cup Plant)
Silphium perfoliatum is a giant wildflower great for large landscapes, with large yellow flowers and unusual cup-shaped leaves. It towers over wet wildflower meadows, attracting both insect pollinators in summer and seed-eating birds in fall.
Silphium perfoliatum is a giant wildflower great for large landscapes, with large yellow flowers and unusual cup-shaped leaves. It towers over wet wildflower meadows, attracting both insect pollinators in summer and seed-eating birds in fall.
Silphium perfoliatum is a giant wildflower great for large landscapes, with large yellow flowers and unusual cup-shaped leaves. It towers over wet wildflower meadows, attracting both insect pollinators in summer and seed-eating birds in fall.
Silphium perfoliatum or Cup Plant is a unique perennial, best utilized in large landscapes where its full benefits can be appreciated. This is one of our tallest wildflowers, reaching up to 8’ in height with a 3’ width. The flowers are large and showy, bright yellow, similar to sunflowers but with their own distinction. The blooms can last for weeks from June to August, but the common name of the plant comes from the unusual shape of the leaves which grasp the stalk in a “cup” shape. The size of the plants makes them more challenging to use in a confined garden space, but they work well when given open room. They can also reseed, and will proliferate in wet, sunny areas - be aware that in the right conditions this will cause Cup Plant to spread! We also recommend checking to ensure that this plant is native in your area - Cup Plant is invasive in some areas of the Northeast. In North Carolina this species is actually a rare plant on our state’s Protected Plant List. It can be grown in full to part sun with medium-dry to medium-wet conditions, making it drought tolerant when established and a great choice for large rain gardens.
When reading about the size and growing range of Silphium perfoliatum some may wonder how valuable a wildflower this really is. Aside from this being a rare plant native to our region, Cup Plant provides a number of unique ecological services in addition to its value as a pollinator plant. The water-holding capacity of Cup Plant is interesting, and by catching rainwater it provides not only water as a readily available resource for wildlife, but also can trap insects as food for birds. Cup Plant’s large size makes it useful in prairies and meadows that otherwise lack trees and shrubs, providing shelter for birds in the heat of summer, and prolific food for a variety of insects. It attracts bees, butterflies, and predatory insects with its large, open flowers, and a number of specialist insects feed on various parts of Cup Plant and other Silphium species exclusively. In the right conditions, this species can be a great choice for the landscape.
Pollinators: bumblebees, cuckoo bees, halictid bees, leafcutter bees, long-horned bees, miner bees, honey bees, butterflies, bee flies, syrphid flies, wasps
Host Plant for Butterflies/Moths: Giant Eucosma (Eucosma giganteana), some members of Papaipema genus also feed on Silphium species.
Dependent Species: 7 species of oligolectic bees in our region depend on Silphium species as one of their only sources of food; Giant Eucosma (Eucosma giganteana)
Wildlife Value: Hummingbirds, Songbirds, Wood Warblers, shelter, winter cover, katydids, water reservoir for wildlife
Deer Resistance: Good
Native Region: Appalachian Mountains, Piedmont
Seed Origin: USA
USDA Zones: 3-9
States found in our region: AL, KY, NC, PA, TN, VA, WV
Other states found: AR, IA, IL, IN, KS, LA, MI, MN, MO, MS, ND, NE, OH, OK, SD, TX, WI
