The Rudbeckia ‘Sunbeckia’ is a strong growing Rudbeckia hirta cultivar and as long as you provide a ‘Sunbeckia’ with enough fertilizer and some PGR, you can grow wonderful plants, with perfect habbit. In previous reports have pointed out this already-
The below video explains a little how Hartwig Bull is growing his ‘Sunbeckia’ in the north of Germany. I made the video on the 24th June, when the crop was 7 weeks old . The crop was planted in week 19.
More details on growing you find here: Rudbeckia-Sunbeckia-englisch-20-04-10
Details on growing you find also on ghe Flamingo Holland website.