A coarse but bold perennial giant for the back of the border with yellow, daisy-like flowers in summer. Cups form where the toothed leaves meet the thick stems; birds are said to drink from the water held in the cups. Tough prairie natives that will self-sow, these plants need lots of sun and lots of room—a single plant can reach 7 or 8 feet tall and 6 feet across.
CareProvide moist, moderately rich, well-drained, neutral to alkaline soil for best results, but plants are fairly adaptable.
PropagationSow ripe seeds. Divide in spring.
ProblemsDowny mildew, rust.
- Genus : Silphium
- Plant Width : 3 to 6 feet
- Zones : 5, 6, 7, 8, 9
- Plant Height : 6 to 10 feet
- Bloom Time : Early Fall, Late Summer, Summer
- Growth Rate : Fast
- Light : Full Sun to Partial Shade
- Moisture : Medium to Wet
- Maintenance : Moderate
- Plant Type : Perennials
- Characteristics : Self Seeds
- Plant Seasonal Interest : Summer Interest
- Flower Color : Yellow