Heliopsis isn't a true sunflower and it doesn't grow into a giant stalk. I'm not sure why it got its common name, except that the bright yellow flowers are indeed sunny. They also bloom almost all summer. It forms a nice fat clump, but it may need some staking, particularly when it gets wet. Deadheading keeps the flowers going longer and helps maintain a more attractive look to the plant.
Heliopsis helianthoides (Sunflower heliopsis) 'Golden Plume' (USDA Zones 3 - 9, 48" x 36", Orange/Gold Blossoms: June - Aug.)
Alternative
- Coreopsis grandiflora (Large Flowered Tickseed) (USDA Zones 4 - 9, 30" x 36", Orange/Gold Blossoms: June - Sept.)