Rudbeckia fulgida var. sullivantii 'Goldstrum' 'Goldstrum' orange coneflower Size: 24 to 42" high and 1 to 2' wide. Hardiness: Zones 3 to 9. Heat Zones: 9 to 1. Habit: The flowers of this popular species sport yellow petals surrounding a purplish brown central cone. The midsummer-to-late-fall flowers bloom above a mound of dark green, slightly hairy foliage. Culture: Full Sun to light shade.