Cup Plant (Silphium perfoliatum)
Standing tall at around six feet (more in wetter soils, less in drier soils), Cup Plant's yellow blossoms can be seen starting in July when the butterflies visit them, and then later when the birds begin to feed on its seeds. Throughout the growing season, the water held in the leaf cups attract birds and other critters looking for a drink. Cup Plant establishes well in average garden soil or in heavier, wetter soils. It is easy to start from seed by fall planting outdoors, or, if planted in spring, a period of 60 days of moist, cold stratification is recommended prior to sowing. A vigorous plant throughout its range, this species can be invasive when planted outside of its historic regions.
Sun Exposure - Full, Partial
Soil Moisture - Medium-Wet, Medium
Height - 6 feet
Bloom Time - July, August, September
Bloom Color - Yellow
Photo courtesy of Prairie Moon Nursery.