Prairie Dock (Silphium terebinthinaceum) is a structural plant with very tall spires of yellow flowers from mid-summer to early fall and large, distinctive foliage. They prefer full sun in mesic to dry soil where they grow up to 12 feet tall. They are a good choice for the slopes and banks of larger bioretenion installations. Companion plants include Smooth Blue Aster (Symphyotrichum laeve) and Prairie Dropseed (Sporobolus heterolepis).
Maintenance
No serious maintenance concerns. When in bloom, plants may need staking.
About
Light Requirements
Sun Moisture Requirements
Banks,
Slopes Soil Requirements
Loam Height
Tall,
Very Tall Spacing
2 to 3 feet Category
Structural Attracts
Bees,
Hummingbirds Illinois Native Plant Status
Illinois Native,
Indiana Native Bloom Time
July,
August,
September Bloom Color
Yellow Seasonality
Fall,
Spring,
Summer,
Winter Sociability
Individuals, Groups up to 5