Variety traits

Abundance and Duration of Flowering — Black-eyed Susan, Coneflower

Rudbeckia hirta L.

The flowering duration of Rudbeckia hirta L. is 8–12 weeks, beginning between late June and August. Abundance is assessed by the density of inflorescences per plant and their diameter, which varies from 7 to 20 cm depending on the cultivar.

In the reference 6 varieties crop Black-eyed Susan, where this is mentioned in the description.

Rudbeckia hirta is characterized by a prolonged flowering period, which continues until the first frost, provided that faded inflorescences are regularly removed. In professional agronomic guides, qualitative characteristics such as inflorescence stand density and the total number of buds per plant are used to describe flowering.

The plant is a long-day crop and requires a photoperiod of at least 14 hours for successful flowering initiation. Agronomic management of flowering includes maintaining irrigation during dry periods and applying balanced fertilizers with a predominance of potassium to stimulate bud formation at optimal temperatures of 18–25°C.

General information about the subject — on the page Abundance and duration of flowering.

Sources8

Varieties of Black-eyed Susan mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.