Astilbe ‘Bremen’ is a popular and vibrant perennial that adds color and texture to shaded garden spaces. Its feathery plumes and deeply divided foliage provide visual interest from spring through summer. Resilient and adaptable, it’s a favored choice for enhancing garden areas where other flowering plants struggle.
Understanding Astilbe ‘Bremen’
This mound-forming perennial reaches a mature height of 18 to 24 inches, with its flower plumes extending up to 24 inches, and spreads about 24 inches wide. It features glossy, mid- to dark green leaves that are ovate to lance-shaped and deeply divided, providing an appealing fern-like texture throughout the growing season.
The plant produces erect stems topped with branched, triangular panicles of reddish-pink flowers from late spring to early summer. Astilbe ‘Bremen’ is hardy in USDA Zones 3 to 9, making it suitable for a wide range of climates. Its low-maintenance nature and ability to attract butterflies, while being less appealing to deer.
Planting and Site Selection
Astilbe ‘Bremen’ thrives in light to moderate shade, performing best with dappled sunlight or morning sun and afternoon shade. Full sun exposure, especially in hotter climates, can lead to scorched foliage and reduced flowering.
It requires consistently moist, fertile, and well-draining soil rich in organic matter, with a slightly acidic to neutral pH. To prepare the planting site, amend the soil generously with compost or aged manure to improve fertility and moisture retention. When planting, ensure the crown of the plant sits just below the soil line, with roots fanned out, and space plants 18 to 24 inches apart for proper air circulation and growth.
Ongoing Care
Consistent moisture is crucial for Astilbe ‘Bremen’, as it does not tolerate dry conditions. During dry periods, water regularly and deeply, ensuring the soil remains consistently moist but not waterlogged. Applying organic mulch around the base helps retain soil moisture, regulate soil temperature, and suppress weeds.
Astilbe ‘Bremen’ benefits from annual fertilization for vigorous growth and abundant blooms. Apply a balanced, slow-release fertilizer in early spring as new growth emerges, or a liquid fertilizer in June and July. While deadheading spent flower plumes is not strictly necessary for plant health, it can improve appearance. For winter preparation, the foliage can be left to provide insulation and winter interest, or cut back to a few inches above the ground after it dies back in late fall or early spring.
Propagation
Division is the most effective and common method for propagating Astilbe ‘Bremen’, also maintaining vigor. Mature clumps benefit from division every three to four years, ideally in early spring before new growth begins or in the fall after flowering. This process rejuvenates older plants and provides new specimens for other areas of the garden.
To divide, carefully dig up the entire plant clump, taking care not to damage the rhizomes. Gently separate the rhizomes, ensuring each new section has three to five “eyes” or growth points and a healthy portion of roots. Replant these divisions at the same depth as the original plant, spacing them appropriately, and water thoroughly to help them establish in their new locations.
Common Issues and Solutions
Astilbe ‘Bremen’ is resilient, but it can encounter common issues, primarily environmental. Leaf scorch, characterized by browning leaf margins, indicates too much direct sun exposure or insufficient moisture. Ensuring the plant is in partial to full shade and receives consistent watering can prevent this problem.
Powdery mildew, a fungal disease, may appear as a white, powdery substance on leaves, especially in humid conditions with poor air circulation. To mitigate this, ensure adequate spacing between plants to promote airflow and avoid overhead watering, focusing water at the base. If issues persist, a fungicide can be applied. Root rot is another potential problem in poorly drained or overly saturated soils, highlighting the importance of well-draining planting sites.