Siberian bugloss (Brunnera macrophylla)
Siberian bugloss (Brunnera macrophylla) is a shade-loving perennial prized for heart-shaped foliage and delicate blue spring flowers.
Complete Plant Information
Overview
Brunnera macrophylla, commonly known as Siberian bugloss, is an outstanding herbaceous perennial highly valued for introducing bright color and texture to deep shade gardens. It forms attractive basal mounds of heart-shaped leaves that remain lush throughout the growing season, providing essential structure where few other plants thrive. The plant offers a lovely spring display of airy, intense blue flowers resembling forget-me-nots, rising above the foliage mound. Belonging to the Boraginaceae family, this low-maintenance perennial slowly spreads to create beautiful, dense ground covers in woodland settings.
The primary appeal of Brunnera macrophylla is its combination of durable, attractive foliage and delicate spring bloom. While native primarily to Turkey, Siberian bugloss performs well across USDA Zones 3 through 8 when given the proper cool, shady environment. Gardeners appreciate this plant for its ease of care and its ability to naturalize gracefully over time, requiring minimal intervention once established.
Fast Facts
- Plant Family: Boraginaceae
- Plant Type: Herbaceous perennial
- Native Range: Turkey
- Hardiness Zones: USDA Zones 3-8
- Size at Maturity:
- Height: 1-1.5 ft
- Spread: 1.5-2.5 ft
- Bloom Time: April to May
- Bloom Description: Intense blue
- Sun Exposure: Part shade
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
Brunnera macrophylla is best planted in spring or fall when temperatures are mild. For optimal results, locate it in areas receiving consistent part shade. The species thrives in average, well-drained soil, although it strongly prefers organically rich, consistently moist conditions. Incorporating compost before planting improves structure and water retention, which is crucial for establishing a healthy colony.
Watering should be consistent, aiming for medium moisture levels. While this Siberian bugloss tolerates some dryness better than many shade companions, it will struggle if allowed to dry out completely, particularly during hot spells. Fertilizing is generally unnecessary if the soil is organically rich; excessive feeding can sometimes lead to overly lush foliage at the expense of flowers. No routine pruning is required; simply enjoy the foliage display.
Gardeners must note that Brunnera macrophylla prefers cooler summers and may suffer foliage scorch if exposed to intense afternoon sun, especially outside the prime northern zones (it performs poorly in the high heat and humidity of the deep South, Zones 7-9). Clumps naturally spread via creeping rhizomes, creating wonderful ground cover. If you are growing variegated forms, be aware that self-seeded plants may revert to plain green foliage.
Landscape Uses
Brunnera macrophylla excels as a foundational element in structured shade gardens. Its spreading habit makes it an excellent choice for mass planting or utilizing as an effective ground cover beneath mature trees where lawn grass struggles. Use groupings of Siberian bugloss to define the edges of woodland borders or to soften the damp edges of ponds and streamsides.
The dramatic foliage provides a strong vertical and horizontal contrast against ferns and hostas, offering year-round interest. While the standard forms are fantastic for naturalized areas, variegated selections shine in containers or as specimens near pathways where their leaf patterns can be fully appreciated. Ensure planting partners share similar preferences for part shade and medium, consistent moisture levels.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Brunnera macrophylla, commonly called Siberian bugloss, is a rhizomatous, clump-forming, herbaceous perennial primarily grown for its attractive heart-shaped, dark green, basal foliage. Small, intense blue, forget-me-not-like flowers bloom in airy racemes rising above the foliage in spring, creating a lovely contrast. The genus name derives from Swiss botanist Samuel Brunner, while macrophylla means large-leaved, referencing the substantial basal leaves.
Tolerances
- Rabbit
Potential Problems
Siberian bugloss generally exhibits robust health, facing no serious insect or disease pressures in most landscapes. The most common visitors are slugs and snails, which appreciate the lush, moist environment favored by this plant. To manage these pests, apply traditional slug bait or diatomaceous earth around the base of the plants early in the season, focusing efforts on keeping the leaf litter thinned slightly to reduce hiding spots. Rabbits typically ignore Brunnera macrophylla, offering reliable browsing resistance.
Frequently Asked Questions
What hardiness zones is Siberian bugloss suitable for?
Brunnera macrophylla is adaptable and hardy across USDA Zones 3 to 8, providing excellent performance in cold winter regions.
How large does Brunnera macrophylla grow?
This perennial typically reaches a height of 1 to 1.5 feet and spreads to a width of 1.5 to 2.5 feet as its rhizomes creep.
What sun exposure does Brunnera macrophylla need?
Siberian bugloss requires part shade to thrive; too much direct sun, especially hot afternoon sun, can cause the foliage to scorch.
When does Siberian bugloss bloom?
Brunnera macrophylla flowers profusely in spring, typically from April through May, exhibiting its signature intense blue color.
Conclusion
The Brunnera macrophylla offers exceptional value to the shade garden, combining persistent, attractive heart-shaped foliage with a stunning display of blue flowers in early spring. Siberian bugloss remains a reliable, low-maintenance choice for creating dense ground cover in woodland areas. Before planting, confirm your location falls within USDA Zones 3-8 and ensure the site offers consistent moisture and protection from harsh afternoon sun.
Companion Planting
Selecting successful companion plants relies on matching the need for part shade and consistently moist, organically rich soil. Hostas are classic partners, pairing well with the contrasting leaf textures and forms of Brunnera macrophylla. Ferns, particularly wood ferns (Dryopteris), also provide an excellent textural contrast beneath the spreading habit of Siberian bugloss. Consider planting spring ephemeral bulbs like bloodroot or trillium nearby; they will emerge and flower before the Brunnera foliage fully matures and dominates the space.
Design Ideas for Woodland Gardens
The rhizomatous nature of Brunnera macrophylla makes it ideal for filling the middle layer of a woodland garden design. Plant in sweeping drifts rather than single specimens to maximize the visual impact of its foliage mound throughout the season. Where the ground receives dappled light but remains dry in late summer, ensure you select cultivars known to tolerate slightly drier soil better than others, though moisture remains preferred. Use the distinct dark green leaf color to anchor contrasting silver-leaved shade plants, creating depth and definition in darker garden corners.
