Plant Profile: Rudbeckia hirta

Black-Eyed Susan is a robust, moderately fast-growing biennial or short-lived perennial that originates from the eastern United States but has spread widely across North America. Often regarded as an annual due to its ability to bloom in the first year when seeds are sown in early spring, it readily self-seeds and typically persists in gardens. In North Carolina, this plant can grow as a biennial, reaching heights of up to 4 feet, and is commonly found along banks and roadsides.

The leaves of Black-Eyed Susan are arranged alternately and feature either serrated or nearly smooth edges, with some exhibiting three or more lobes. The flowers consist of a brown, rounded center encircled by vibrant yellow ray florets, which can sometimes appear orange. These flowers begin to bloom in mid-summer and, with regular deadheading, can continue to flourish into mid-fall.

This plant is forgiving of neglect and demonstrates moderate drought resistance. It thrives in average, well-drained soil and prefers full sun to partial shade. To achieve the best floral display, it’s essential to provide adequate sunlight and avoid planting near lawn edges where excess nitrogen from fertilizers can hinder growth.

In terms of pests and diseases, Black-Eyed Susan faces no significant threats. However, it can be prone to powdery mildew and may attract slugs and snails, particularly on younger plants. It is also known for its ability to self-seed abundantly.