Ask Mr. Smarty Plants

You are correct, Rudbeckia fulgida var. sullivantii 'Goldsturm' is usually a very reliable bloomer. The Missouri Botanical Garden have the following information about Goldsturm Rudbeckia on their website...

Easily grown in average, dry to medium, well-drained soil in full sun. Tolerates hot and humid summers and some drought. Tolerates light shade, but best in full sun. Deadhead to prolong bloom. Divide when clumps become overcrowded. Plants do not come true from seed (must be vegetatively propagated). Some nurseries sell seed-grown plants, however, as Goldsturm strain.

This coneflower cultivar is an upright, rhizomatous, clump-forming perennial which typically grows 2-3' tall. Features large, daisy-like flowers (3-4" across) with deep yellow rays and dark brownish-black center disks. Flowers appear singly on stiff, branching stems in a prolific, long-lasting, mid-summer-to-fall bloom. Oblong to lanceolate, dark green foliage. Good fresh cut flower. Mass in bold drifts in the perennial border, cottage garden, prairie, meadow or naturalized area. Provides excellent bloom and color for late summer.

A common problem of this cultivar is angular leaf spot caused by a bacterium. The disease causes brown or black angular spots on the leaves which can expand to blacken the whole leaf. Infection begins on the lower leaves and moves up the plant. Rudbeckias are also susceptible to septoria leaf spot and powdery mildew.

Rudbeckia, though, are sometimes attacked by a bacteria-like organism called Aster Yellows that is spread from plant to plant by a leafhopper. The University of Minnesota Extension have the following information: Aster yellows has an exceptionally large host range that includes purple coneflower, aster, marigold, goldenrod, cosmos and other members of the daisy family (Compositae). The symptoms that result from this disease are witches' brooms, flowers appearing out of the 'cone', leaves sprouting from flowers, dwarfing and yellows. The pathogen, a phytoplasma, is a bacterium-like organism without the cell wall. It is an obligate pathogen and can be conclusively identified only by laboratory analysis.The phytoplasma is spread by a leafhopper vector. Management options are limited to 'search and destroy'. Infected plants should be removed and thrown away. Early season control of the leafhopper vector and removal of weed hosts may help prevent re-infection.