Silphium Perfoliatum

Cup Plant

The Cup Plant is an erect herbaceous perennial with triangular toothed leaves, and daisy-like yellow composite flower heads in summer. The flowers, which appear from mid-summer to autumn are similar in appearance to sunflowers, measuring about 2.5 cm in diameter, with golden yellow ray florets. Cups form where the toothed leaves meet the thick stems; birds are said to drink from the water held in the cups. It is best planted in groups and not individually, so that the flower stalks can fall over some when planted by itself.

Contributed by @moore.794

plant Features

Full sun to partial shade
Very little water
Full Frost Hardy: 5F (-15°C)
Moist and free draining

plant information

Common name

Cup Plant

Latin name

Silphium Perfoliatum

type

Herbaceous Perennials

family

Asteraceae

ph

5.0 - 7.0 Acid - Neutral

Light

Full sun to partial shade
Frost

Full Frost Hardy: 5F (-15°C)

Soil

Moist and free draining
Water

Very little water

Plant & bloom calendar

Best time to plant

full grown dimensions

The size of a fully grown Cup Plant is 1.00meters x 2.20meters

1.00 M 2.20 M

Silphium Perfoliatum

Planting young plants

From Early Spring TO Early Spring

Plant out at the back of the border in full sun, in a moist but well drained soil. Dig in plenty of well rotted compost before planting. It is best planted in groups and not individually, so that the flower stalks can fall over some when planted by itself. Otherwise, plant close to a trellis where the plants can be tied as they grow taller, to provide support to the flowering stems.

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