Masterwort (Astrantia major 'Claret')
Astrantia major 'Claret' (Masterwort) offers stunning wine-red blooms from May to July in part shade gardens.
Complete Plant Information
Overview
Astrantia major ‘Claret’, commonly known as Masterwort, is a highly valued herbaceous perennial prized for its unique, star-like flower heads and long blooming season. This cultivar brings deep, wine-red coloring to garden scenes, contrasting beautifully with its deeply divided, medium-green basal foliage. It thrives best where it receives part shade, making it an excellent choice for woodland edges and dappled light areas.
The structure of the Masterwort flower, featuring tiny florets surrounded by papery, petal-like bracts, offers sustained visual interest long after the initial bloom. Astrantia major ‘Claret’ naturally forms colonies over time via stolons in optimal conditions, creating a lush, textured groundcover effect without being aggressive. Gardeners appreciate its reliability and its suitability for both fresh cuts and dried arrangements.
While adaptable, achieving the best performance from Astrantia major ‘Claret’ requires consistent moisture, reflecting its natural preference for moist European meadows. Providing a rich, well-drained soil base and avoiding high summer heat stress will reward you with vibrant, dark red blooms throughout late spring and early summer.
Fast Facts
- Plant Family: Apiaceae
- Plant Type: Herbaceous perennial
- Hardiness Zones: USDA Zones 4-7
- Size at Maturity:
- Height: 1-2 ft
- Spread: 0.75-1.5 ft
- Bloom Time: May to July
- Bloom Description: Wine red
- Sun Exposure: Part shade
- Water Needs: Medium to wet
- Maintenance Level: Medium
How to Grow
Plant Astrantia major ‘Claret’ in spring or early fall once the danger of hard frost has passed, placing it in organically rich, well-drained soil. While it prefers part shade, in cooler, temperate climates, it may handle full sun, provided the soil remains consistently moist throughout the growing season. Avoid planting locations where the soil is prone to drying out completely, as this Masterwort dislikes drought.
Ongoing care centers around soil moisture management; ensure the soil stays uniformly moist, especially during dry spells in summer. Fertilization is usually minimal if the soil is rich; overly rich soil can sometimes encourage excessive foliage growth over flowering. Deadheading spent flowerheads immediately after bloom is beneficial if you wish to prevent self-seeding and potentially encourage a second, lighter flush of flowers.
Performance peaks in cooler summer climates where night temperatures reliably dip below 70°F. In hot, humid summers, monitor the plant closely for signs of stress, such as wilting. Minimal winter preparation is typically needed in its established hardiness range; a light layer of mulch can help buffer soil temperatures during harsh winters.
Landscape Uses
The deep coloring and airy texture of Astrantia major ‘Claret’ make it a superstar for the semi-shaded areas of perennial borders. It blends beautifully with ferns, hostas, and other shade-loving foliage, offering vertical accents among lower-growing groundcovers. Consider using this Masterwort in open woodland settings or cottage gardens where its naturalizing habit can be celebrated.
This perennial thrives along moist stream banks, staying above the waterline, or in sun-dappled areas beneath open tree canopies. While plants will happily spread by stolons to fill open spaces in woodland gardens, they are not considered invasive, making them dependable fillers. Furthermore, the distinctive flower heads provide excellent material for creating unique dried flower arrangements.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Astrantia major, commonly called greater masterwort, is an upright, umbelliferous, stoloniferous, herbaceous perennial native to mountain meadows and woodland clearings in Europe and western Asia. Each flowerhead features dense, compact, domed umbels of tiny flowers subtended by a showy collar of papery, petal-like involucral bracts. ‘Claret’ is a superior cultivar noted for its dark red flowers and nearly black stems, typically growing to 24” tall with leaves palmately cut into 3-7 toothed lobes.
Tolerances
- Wet Soil
Potential Problems
Astrantia major ‘Claret’ generally resists serious insect or disease issues, contributing to its low-maintenance appeal. The primary occasional visitor noted is the slug, which may chew on the leaves, particularly when moisture levels are high. To manage slugs, employ standard organic controls such as beer traps or scattering diatomaceous earth around the base of the plants, especially during damp weather periods.
Frequently Asked Questions
What hardiness zones is Masterwort suitable for?
Astrantia major ‘Claret’ is reliably hardy across USDA Zones 4 through 7.
How large does Astrantia major ‘Claret’ grow?
This Masterwort typically reaches a mature height between 1 and 2 feet, with a spread of 0.75 to 1.5 feet tall and wide.
What sun exposure does Masterwort need?
This plant requires part shade; consistent moisture must be maintained even if it receives a little extra sun exposure.
When does Astrantia major ‘Claret’ bloom?
You can expect the distinctive wine-red flowers of Astrantia major ‘Claret’ to appear from May through July.
Conclusion
The dark, rich color offered by Astrantia major ‘Claret’ provides sophisticated texture and reliable performance in cooler, moist garden spots. As a fantastic Masterwort cultivar, it deserves consideration for woodland edges and shaded borders seeking season-long interest. Check your local climate to ensure cool summer nights are likely, and plant early for best establishment this season.
Companion Planting
Grouping Astrantia major ‘Claret’ with complementary shade-lovers enhances its structural contribution. Consider pairing it with Hosta varieties that have blue or chartreuse foliage to create vibrant color contrasts against the dark red blooms. Astilbe works well alongside Masterwort, as both plants share a similar requirement for moisture-retentive, rich soils and partial shade conditions.
For a woodland tapestry look, interplant Astrantia major ‘Claret’ with native foamflower (Tiarella) or bleeding hearts (Dicentra spectabilis). These companions share similar cultural needs and bloom times, creating a layered effect that celebrates dappled sunlight filtering through the canopy.
Propagation Tips
Astrantia major ‘Claret’ is a stoloniferous perennial, meaning it spreads slowly beneath the surface by underground runners. The most direct method of increasing your stock is through simple division, which should be performed in early spring before new growth vigorously emerges or in the early fall. Gently lift the clump and carefully separate viable sections, ensuring each division retains a healthy set of roots and viable growing points.
While the plant may self-seed, named cultivars like ‘Claret’ may not come reliably true from seed, making division the preferred route for maintaining the specific dark red flower color. If dividing, aim to place the new clumps in soil that is already richly amended with organic matter to support their establishment in their new location quickly.
