Black-Eyed Susans, part of the Rudbeckia genus, are bright, cheerful flowers that provide a vibrant display of yellow and orange late into the season. Their long blooming period often extends through late summer and into the fall, making seasonal care an important consideration. As the weather cools and the plants fade, post-bloom management significantly impacts both the plant’s health and the garden’s winter ecosystem. Proper fall care sets the stage for healthy growth and a robust return of blooms the following year. This transition involves decisions about tidiness, hygiene, and ensuring the continued vitality of the plant population.
The Fall Decision: To Cut Back or Leave Standing
Gardeners face a choice in the fall: whether to cut back the spent stems of Black-Eyed Susans or leave them standing for the winter. Cutting the plants down provides a neat, manicured appearance, which many gardeners prefer for winter aesthetics. This practice minimizes the likelihood of certain diseases, such as powdery mildew, overwintering on dead foliage and infecting new growth next spring. Removing the faded flowers also prevents the plant from self-seeding, which helps maintain precise control over where new plants emerge.
Conversely, leaving the stalks standing offers substantial benefits to the local environment during the colder months. The dried seed heads serve as a valuable food source, particularly for birds like American Goldfinches. Standing stems also provide shelter and overwintering habitat for beneficial insects and their eggs, contributing to a healthy garden ecosystem. This approach offers visual interest, as the brown, conical seed heads and stems provide texture against a winter landscape. The decision ultimately balances a preference for order with a desire to support wildlife and natural processes.
End-of-Season Maintenance and Garden Hygiene
Regardless of the decision to leave the stalks or cut them, end-of-season maintenance prepares the garden bed for dormancy. If you remove the stems, use clean, sharp shears to make cuts about four to six inches above the soil line, leaving a small stubble to protect the crown. If any foliage or stems showed signs of fungal disease, such as leaf spot or powdery mildew, those materials should be completely removed and disposed of away from the garden, rather than composted, to prevent the pathogen from overwintering.
Thorough weeding around the base of the plants reduces competition for moisture and nutrients and removes potential hiding spots for pests. Once cleared, a light layer of organic mulch, such as shredded leaves or compost, can be applied around the crown of perennial varieties. This mulch helps regulate soil temperature, protecting the plant’s roots from damaging freeze-thaw cycles that can heave the plant out of the ground during winter.
Preparing for Next Year: Division and Seed Saving
Fall is an excellent time to divide perennial varieties, such as Rudbeckia fulgida ‘Goldsturm,’ a process that rejuvenates older, overcrowded clumps. Black-Eyed Susans benefit from division every three to four years, especially when flowering begins to diminish in the center. This must be done well before the first hard frost (typically four to six weeks prior) to give the separated root sections time to establish new anchor roots.
To divide the plant, carefully dig up the entire clump and use a sharp spade or knife to separate the root mass into smaller sections, ensuring each new piece has healthy roots and several young shoots. Replant these divisions immediately into prepared soil amended with compost, watering thoroughly to settle the soil around the roots.
For gardeners wanting to expand their stock, mature seed heads can be collected once they have turned brown and dried completely on the plant. The tiny black seeds are easily separated from the chaff by rubbing the dried cones over a paper surface. After drying the seeds for one to two weeks, store them in a labeled paper envelope until planting next season.