CUP PLANT Silphium perfoliatum
Silphium perfoliatum, the cup plant or cup-plant, is a species of flowering plant in the family Asteraceae, native to eastern and central North America. It is an erect herbaceous perennial with daisy-like yellow flowers in summer. The plants has a long blossoming season and abundance of flowers.
The typical height of this plant ranges from 1–2.5 m (3–8 ft). The first flower develops on the tip of the main stem, then more flowers develop on side branches.
The flowers, which appear from midsummer to autumn (fall), look very similar to sunflowers, measuring about 2.5 cm in diameter, with golden yellow ray florets.
Insect pollinators including bees, butterflies, and skippers help to cross-fertilize flowers to produce seeds. Each seed is about 9 to 15 mm long, 6–9 mm wide, flattened in shape, with a thickness of 1 mm.
S. perfoliatum grows in sandy moist bottom lands, floodplains, near stream beds, in or adjacent to open woodland. Currently, it can be found in the following states: USA (AL, AR, CT, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, ND, NE, NJ, NY, OH, OK, PA, SD, TN, VA, VT, WI, WV), CAN (ON, QC). In the 1750s, the species was introduced to the United Kingdom and the Soviet Union, and has been prized as an ornamental plant since. It has gained the Royal Horticultural Society's Award of Garden Merit.
This plant is often used in prairie and native meadow restorations and in native, naturalistic landscapes and gardens, and in conventional landscapes and gardens by landscape designers and architects that know of it as a unique looking perennial. In gardening and landscaping it is best used in groups and not individually, as it is so vertical and the flower stalks are more likely to fall over some when by itself.
Type: Hardy perennial
Height: 1–2.5 m (3–8 ft)
Location: Sun or part sun
Hardiness zones: 4-8
Seeds per pack: 10
Germination: As with many perennials, these seeds require a period of moist cold to help them break dormancy. This is done by giving them a cold 'winter' period (artificial or natural), and then a warming to simulate 'spring', and time to grow! Here's how this can be done:
Obtain a planting container that has holes in the bottom for excess water to drain. Place the seeds just under the surface of your growing medium, and water. Place your container in a cold area (but not freezing, perhaps a refrigerator) for 5-6 weeks. Once the cold period is completed, place the container at room temperature for them to germinate. Be sure to keep the soil moist during this entire germination period.
