Also known as prairie sunflower this herbaceous perennial is native to central US and is a member of the aster family, Asteraceae, that also includes daisy, yarrow, and lettuce. It has a root system with long rhizomes and a central stem that is prickly, green to reddish brown, and unbranched or sparingly branched toward the apex. Plants may grows up to 6′ tall but many are only 1-2′ tall. The opposite , hairy, lanceolate leaves grow mostly on the lower half of the stem and are dull gray-green and 2-10″ long. The petioles are short and thick and the leave margins have shallow, widely spaced teeth. From late summer to early fall 1-5 flowerheads appear on almost naked branches of each plant. The flowers are up to 4″ across and have 10-20 yellow ray florets surrounding 75 reddish to purplish-brown disc florets. The ray florets may twist or fold up in dry weather. The roots are allelopathic so although colonies develop they may die out in the center. Plants are somewhat more drought tolerant than other species and they are a good choice for native plant, wildflower, and wildlife gardens. They are somewhat aggressive and may not be a good choice for a small garden. The genus name, Helianthus, comes from the Greek words helios, meaning sun, and anthos meaning flower and and may refer to the resemblance of the flowerhead to the sun. The specific epithet, rigidus, is the Latin word for stiff and refers to the hairs on the leaves an stems.
Type: Herbaceous perennial
Bloom: Flowerheads up to 4″ across with yellow ray flowers and reddish to purplish-brown disc flowers from late summer to early fall
Size: 5-6′ H x 2′ W
Light: Full sun
Soil: Average, medium moist, well-drained
Hardiness: Zones 3-10
Care: Low maintenance
Pests and Diseases: Powdery mildew
Propagation: Seed, division
Companion Plants: Purple Coneflower (Echinacea purpurea),Black-eyed Susan (Rudbeckia hirta), Switchgrass (Panicum virgatum)
Karen Meyers