Bellflower (Campanula 'Sarastro')
Campanula 'Sarastro' is a low-maintenance herbaceous perennial bearing deep blue, bell-shaped flowers from June to August.
Complete Plant Information
Overview
The Campanula ‘Sarastro’, a robust hybrid Bellflower, is highly valued by gardeners for its reliable performance and striking floral display. It produces large, deep blue, bell-shaped flowers that droop elegantly from leafy stems throughout the mid to late summer months, offering reliable color when many spring bloomers fade. This herbaceous perennial is known for being easily grown and requires relatively low maintenance once established in suitable conditions.
Campanula ‘Sarastro’ features a clumping habit, typically reaching two feet tall and wide, forming neat mounds of medium green, shiny foliage from which the flowers emerge. As a hybrid of C. Punctata and C. Trachelium, it combines vigor with an attractive form useful in various garden settings. Gardeners appreciate this Bellflower for its strong stems, making it visually appealing in borders and containers.
A key characteristic of Campanula ‘Sarastro’ is its moderate spreading nature via rhizomes under optimal conditions, which can help it form effective ground cover over time, though this spreading requires occasional management. Providing consistent moisture and ensuring moderately cool nights will maximize the performance of this exceptionally blue flowering plant.
Fast Facts
- Plant Family: Campanulaceae
- Plant Type: Herbaceous perennial
- Hardiness Zones: USDA Zones 4-8
- Size at Maturity:
- Height: 1.5-2 ft
- Spread: 1.5-2 ft
- Bloom Time: June to August
- Bloom Description: Deep blue
- Sun Exposure: Full sun to part shade
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
Planting Campanula ‘Sarastro’ is best accomplished in spring or fall when conditions are cool. Aim for average, medium, well-drained soil richness. While it tolerates full sun, placing this Bellflower where it receives afternoon shade, especially in hot climates, prevents stress. The location is crucial: it struggles where night temperatures consistently fail to drop below 70 degrees F.
Once situated, the ongoing care for Campanula ‘Sarastro’ is straightforward, focusing primarily on consistent moisture delivery. It requires medium water needs, so avoid letting the soil dry out completely, especially during peak summer heat or bloom time. Fertilization is rarely necessary if planted in decent garden soil.
To keep the clump looking fresh and encourage a potential rebloom, deadhead spent flowers or shear the plants back to the basal foliage immediately after the main bloom finishes in August. Every three to four years, divide the clumps during the fall to maintain vigor and manage its tendency to spread freely via rhizomes.
Landscape Uses
The deep blue display of Campanula ‘Sarastro’ makes it an excellent structural element for traditional cottage gardens, providing vertical interest without becoming overgrown. Its compact yet substantial presence is ideal for the front or middle of borders, contrasting nicely with silver-leaved or yellow-flowering perennials. Grouping or massing these Bellflowers together maximizes the visual impact of their rich color.
Due to their strong, upright stems, these plants perform admirably in containers, softening hard edges on patios or decks. They also translate well into rock gardens where drainage is naturally excellent, or used sparingly in lightly shaded woodland settings to brighten dappled light areas. For broad coverage, utilize the moderately spreading habit of Campanula ‘Sarastro’ as an effective ground cover in defined beds.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Campanula is a genus of about 300 species of annuals, biennials and perennials from throughout temperate regions of the northern hemisphere found from alpine areas to meadows and woodlands. Many make excellent garden plants.Genus name comes from the Latin campana meaning bell in reference to the bell-shaped flowers. ‘Sarastro’ is a clumping, hybrid bellflower (reportedly C. Punctata x C. Trachelium) noted for producing deep blue bell-shaped flowers on slowly-spreading, compact plants that typically rise to 20-26” tall and as wide. Large, shiny, tubular flowers (to 2.5” long) are deep blue to purple blue. Flowers droop from leafy stems over a long mid to late summer bloom. Stems rise up from basal rosettes of medium green leaves.
Tolerances
- Deer
Potential Problems
This variety of Bellflower exhibits excellent disease resistance, boasting no serious insect or disease problems under ideal growing conditions. The primary management concern relates to its spreading habit, which, while useful for ground cover, may require occasional containment depending on garden layout. Gardeners should remain vigilant for common mollusks, specifically watching for slugs and snails, which can damage the lush foliage, particularly when the plants are young or conditions are damp. Use slug bait or manual removal to keep populations in check.
Frequently Asked Questions
What hardiness zones is Bellflower suitable for?
The reliable Campanula ‘Sarastro’ is well-suited for growth in USDA Hardiness Zones 4 through 8.
How large does Campanula ‘Sarastro’ grow?
This hybrid Bellflower generally reaches a mature height between 1.5 and 2 feet tall, with a similar spread of 1.5 to 2 feet wide.
When does Bellflower bloom?
Campanula ‘Sarastro’ displays its signature deep blue flowers consistently throughout the summer season, blooming from June right through August.
What sun exposure does Bellflower need?
For best results, plant this perennial in locations receiving full sun to partial shade, remembering that afternoon shade is beneficial in very hot summer regions.
Conclusion
The inclusion of Campanula ‘Sarastro’ in your perennial borders adds reliable deep blue color and a pleasing, compact structure throughout summer. Its low maintenance requirements and attractive floral display confirm why this Bellflower remains a garden favorite. Before planting, confirm your location falls within USDA Zones 4-8 and prepare well-drained soil for the best long-term success with your new Campanula ‘Sarastro’.
Propagation Tips
Division is the recommended method for increasing your stock of Campanula ‘Sarastro’. Since the clumps benefit from being split every three to four years, this process provides a natural way to generate new plants. Perform the division in the fall after blooming has ceased, ensuring each new section retains a healthy root system and adequate basal foliage to establish quickly.
While this hybrid spreads somewhat freely via rhizomes, divisions ensure you retain the desirable traits of the parent plant. Plant the separated divisions into prepared, well-draining soil immediately and water thoroughly to reduce transplant shock when propagating this beautiful Bellflower.
Companion Planting
When designing settings for Campanula ‘Sarastro’, consider companions that share similar sun exposure and moisture needs. Plants that thrive with medium water supply and prefer dappled sun, such as Astilbe or Hosta varieties with variegation, pair beautifully. This creates a lush, cottage-style tapestry where the deep blue bells of the Bellflower stand out against softer textures.
Avoid planting this Bellflower immediately adjacent to extremely drought-tolerant Mediterranean herbs, as the consistent moisture required by Campanula ‘Sarastro’ may stress the drier-loving species. Successful pairings often involve plants that also benefit from a light mid-summer trim, allowing for cooperative maintenance schedules.
