Brunnera macrophylla, or Siberian Bugloss, is an attractive, shade-loving perennial. Valued for its distinctive heart-shaped leaves, often with silver or white variegation, it provides visual interest. Delicate sprays of small, bright blue flowers, reminiscent of forget-me-nots, emerge in mid-spring. It serves as an effective groundcover, slowly spreading to form dense clumps, and is known for its hardiness.
Site Selection and Initial Planting
Siberian Bugloss thrives in partial to full shade, ideal for woodland gardens or beneath trees. Direct afternoon sun can scorch leaves, particularly variegated varieties, causing foliage to burn or dormancy. While it tolerates some morning sun, consistent moisture is important in brighter conditions.
It prefers moist, well-draining soil rich in organic matter. A slightly acidic to neutral pH is suitable, though it adapts to a range of conditions. Incorporating compost or other organic amendments improves soil structure and fertility.
When planting, space plants 12 to 18 inches apart, allowing for their 18 to 30-inch mature spread. Dig a hole as deep as the root ball and twice as wide, placing the plant so the top is level with the surrounding soil. After backfilling with amended soil, water thoroughly to settle the soil and eliminate air pockets. This is crucial for establishment.
Ongoing Care and Maintenance
Maintaining consistent moisture is important for established Siberian Bugloss, especially during dry spells. It prefers continuously moist soil, but requires good drainage to prevent root issues. During warmer months, regular watering keeps foliage lush and vibrant.
Siberian Bugloss does not require heavy fertilization if planted in rich, amended soil. A light application of balanced, slow-release granular fertilizer or a top-dressing of compost in early spring can provide a nutrient boost. Mulching with organic material, such as shredded bark or leaf mold, retains soil moisture, suppresses weed growth, and moderates soil temperature, gradually adding organic matter.
Deadheading spent flower stalks after spring bloom encourages foliage development, maintaining a tidy appearance. Removing yellowing or damaged leaves improves the plant’s aesthetics and health. In late fall or early spring, old foliage can be cut back to the ground; in warmer climates, foliage may persist through winter. Siberian Bugloss is hardy in USDA Zones 3 to 8, requiring no winter protection.
Troubleshooting Common Issues
Siberian Bugloss is resilient, but environmental factors can lead to issues. Scorched or brown-edged leaves indicate too much direct sunlight or insufficient moisture. Relocating to a shadier spot or increasing watering can alleviate stress.
Yellowing leaves can signal overwatering or poor drainage, potentially leading to root rot. Lack of essential nutrients might also cause foliage discoloration. Ensuring well-draining soil and adjusting watering practices resolves these issues.
While largely pest-resistant, Siberian Bugloss can attract slugs and snails, which chew holes in leaves. Hand-picking these pests in early morning or evening is an effective non-chemical control. The plant exhibits good disease resistance, though in humid or poorly circulated conditions, powdery mildew might appear as a white coating on leaves. Improving air circulation by proper spacing and ensuring good drainage prevents fungal issues.
Propagating Siberian Bugloss
Siberian Bugloss multiplies through division, the most common and effective method. Ideal times for dividing established clumps are early spring as new growth begins or fall after flowering. Dig up the entire plant, then separate the root mass into smaller sections, ensuring each division has roots and healthy growth buds.
Newly divided sections can be replanted immediately into prepared garden beds or containers, following the same planting guidelines. Providing consistent moisture to newly transplanted divisions helps them recover and establish. While propagation from seed is possible, it is slower and may not produce plants identical to the parent, especially with variegated cultivars. Seed-grown plants may revert to the species’ green-leaved form rather than retaining desired variegation.