Cup plant Description:
Silphium perfoliatum, commonly known as cup plant, is a native prairie and wetland plant species that belongs to the sunflower family. It is a tall perennial plant that can grow up to 10 feet in height and is often found in moist soils and along stream banks throughout much of the central and eastern United States. One of the most distinctive features of Silphium perfoliatum is its opposite leaves that fuse together around the stem, forming a cup-like structure that can hold water. This unique adaptation allows the plant to capture rainwater and provides a habitat for insects and other small animals.
Silphium perfoliatum is an important plant for both plant conservation and ecology. It has a deep taproot that can grow up to 10 feet deep, which helps to anchor the plant in place and allows it to access water and nutrients from deep within the soil. This makes it an ideal plant for preventing soil erosion and improving soil structure, especially in wetland habitats. Additionally, Silphium perfoliatum is a valuable source of nectar and pollen for pollinators such as bees, butterflies, and moths, making it an important plant for maintaining healthy ecosystems. Silphium perfoliatum also has a long history of medicinal use by Native American tribes for a variety of ailments, including fever and inflammation. Today, it is still used in herbal medicine as a natural remedy for fevers and as a diuretic.
Cup plant is found in the central and Northeastern United States. In Minnesota, Cup plant is mostly found in the central and southern regions of the state.
Standard Plant Information:
Plant Height: 3' - 10'
Bloom Time: July - September
Preferred Habitat: Does well in full sun and in sandy or loamy soil. Often found in prairies, glades, and roadsides.
For most homeowners, the best option is to scatter seed on the ground by hand broadcasting at a minimum of 16-64 pls ounces per acre. For even coverage, we recommend that you broadcast seed in perpendicular rows across the site to ensure even coverage.
You’ll want to broadcast any grass seed first, which will get raked into the soil lightly. Next, it is ideal to mulch the area lightly with either a clean (no seed) straw or preferably with our native Little Bluestem straw, sold at our retail garden centers. After a light mulching is complete, now it’s time to broadcast your native wildflower seeds, which should not be raked into the soil. A good rain or watering is sufficient to cover the seed.
Simply dig a hole in the soil slightly larger than the plant’s roots. Ensure that the soil line of the plant is maintained during the transfer (i.e. the plant should be at the same level with the ground as it was in the pot). Pack any loose dirt back around the plant and make sure you water it well the same day to ensure it has the best chance of survival.
maps used with permission from MN Wildflowers