Silphium perfoliatum

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Silphium Perfoliatum 7 Silphium Perfoliatum 8 Silphium Perfoliatum 6 Silphium Perfoliatum 5 Silphium Perfoliatum 3 Silphium Perfoliatum
Silphium Perfoliatum 7 Silphium Perfoliatum 8 Silphium Perfoliatum 6 Silphium Perfoliatum 5 Silphium Perfoliatum 3 Silphium Perfoliatum

Silphium perfoliatum

Common Name: Cup Plant

Cup Plant is a robust, towering wildflower that can grow 3 to 8 feet tall. Its large, opposite leaves form unique "cups" around the square stem, which collect rainwater and provide habitat for insects and birds. Bright yellow flowers bloom in mid to late summer, making this plant a valuable resource for pollinators. It is commonly used in prairie restorations, rain gardens, and as a natural screen or border.

Characteristics

Product Form Plant, Seed
Type Forb
Sun Full Sun, Partial Sun
Soil Clay, Loam, Sand/Gravel, Peat, Calcareous
Moisture Mesic, Wet
Average Max Height (inches) 84
Suggested Plant Spacing (inches) 30
Bloom month(s) July, August, September
Bloom Color or Type Yellow
Dominance High

Range Maps

Sowing Information

For most homeowners, the recommended method is to hand-broadcast seed at a minimum rate of 16–64 PLS (Pure Live Seed) ounces per acre. To ensure even coverage, broadcast the seed in perpendicular passes across the site. Grass seed should be broadcast first and lightly raked into the soil. Afterward, apply a light mulch layer using clean, seed-free straw or, preferably, our native Little Bluestem straw, available at our retail garden centers. Once mulching is complete, broadcast native wildflower seed over the area without raking it in. A good rainfall or thorough watering will provide sufficient soil contact for successful germination.

Planting Information

Dig a hole in your planting site slightly larger than the plant’s root system. When placing the plant into the hole, ensure that the soil line remains consistent with its original level in the pot. Fill in around the roots with the excavated soil, gently firming it to eliminate air pockets. Water the plant thoroughly the same day to promote successful establishment.