Brunnera Sea Heart - A Show-Stopping Shade Perennial

Siberian bugloss Sea Heart, Brunnera macrophylla Sea Heart

Brunnera Sea Heart is a show-stopping perennial that brings colour, texture, and cheer to any garden, especially in tricky shade. This refined form of Siberian bugloss is admired for its large, silver heart-shaped leaves with bright green veining and sprays of small, rich blue flowers in spring. A herbaceous perennial that’s as easy to grow as it is rewarding, it’s ideal for ground cover, shady borders, and woodland edges.

Brunnera Sea Heart is an improved selection of Siberian bugloss Brunnera macrophylla, noted for its robust growth and standout foliage. It’s also a PBR cultivar, meaning it’s protected and propagated under strict guidelines, ensuring top-quality plants from your trusted nursery or garden centre.

The foliage is what immediately catches the eye. Large, silver heart-shaped leaves are marked with bright green veins that create a striking pattern. Unlike some varieties that fade in heat, Sea Heart retains its vibrant colour even through summer, resisting frost, heat and humidity. The plant also produces a spray of blue forget-me-not flowers every spring, adding seasonal contrast.

Yes – it’s one of the easiest herbaceous perennials to grow. This plant is ideal for both beginners and experienced gardeners. It thrives in partial to full shade, making it perfect for north-facing beds, woodland gardens, or underplanting larger shrubs.

The key to success is soil. Enrich your planting area with plenty of organic matter, such as compost, to create a moist, humus-rich base. Brunnera macrophylla Sea Heart performs best in well-drained soil that stays evenly moist but never soggy. Once settled in, it’s pretty tolerant of short dry spells.

This plant shines in early spring. That’s when the flowers in spring begin to appear—delicate sprays of small bright blue blooms that float above the leaves. They resemble blue forget-me-not flowers and appear just as the new growth unfurls.

Through summer and into autumn, the vibrant foliage continues to offer structure and interest. In late autumn, the herbaceous top growth naturally dies back. You can cut back the old leaves after the first frosts or leave them in place to provide winter protection until early spring.

Brunnera Sea Heart forms a compact clump that reaches 30 to 45 cm (12 to 18 inches) in height and spread. Its dense foliage provides excellent ground cover, especially when grouped in threes or fives for mass planting.

Because of its size, it’s easy to tuck into a garden border, along a shaded path, or at the edge of a woodland garden. Its tidy habit and decorative leaves make it an ideal foreground plant for layering with taller shade perennials.

One of the biggest highlights of Brunnera Sea Heart is its early-season flower display. It produces sprays of small, rich blue flowers on slender stems that hover above the foliage in early to mid-spring.

These blooms closely resemble forget-me-not flowers, giving rise to the nickname “false forget-me-not”. They add a cheerful burst of colour just when the garden is waking up after winter. After the bloom, the plant continues to shine through its foliage alone.

Absolutely. Brunnera macrophylla Sea Heart makes a gorgeous ground cover for shady areas. Its bold leaves suppress weeds, and its clumping growth habit helps it fill in space without becoming invasive. It’s an excellent plant for covering bare soil beneath trees or along fence lines.

It’s also a good option for mixing with other shade-loving plants, such as hostas, ferns, or hellebores. The silver and green veining contrasts beautifully with darker leaves, while the flowers in spring add seasonal variety.

Caring for this plant is simple. Water regularly during dry weather, especially in its first growing season. Apply mulch each spring to conserve moisture and enrich the soil.

To keep your Brunnera Sea Heart looking its best, remove spent flower sprays after blooming. In autumn, allow the leaves to die back naturally. You can tidy up by removing the dead top growth in winter or early spring. This herbaceous plant will return fresh each year, appearing each spring with renewed strength.

Yes, mature clumps of Brunnera Sea Heart can be divided every three to five years. This helps maintain vigour and allows you to spread it around the garden. Divide in early spring or autumn when the plant is not in active bloom.

Gently lift the clump and use a sharp spade to divide the root mass. Each division should have a healthy root system and a few stems. Replant divisions into enriched soil and water well until established.

Many gardeners compare Brunnera macrophylla Sea Heart to Jack Frost, another popular variety. While both offer silver foliage and blue flowers, Sea Heart has a thicker leaf texture and holds up better in heat and humidity. It also features more pronounced veining and a bolder contrast in leaf pattern.

Both are excellent plants, but Sea Heart tends to be more vigorous and resilient in tougher conditions. If you’re looking for a standout plant with long-lasting colour and low maintenance, Brunnera Sea Heart is the stronger choice.

Brunnera Sea Heart earns its place in my garden every spring, and not just for its charming forget-me-not flowers—though they are a joy when the rest of the garden is still wiping the sleep from its eyes. What keeps me coming back is the foliage. Those bold, silver heart-shaped leaves with green veining hold their structure and colour even through the heat of summer, which is rare for a shade plant. I often tuck it beneath shrubs or let it weave through other shade-loving plants, such as hostas and ferns, where its texture adds depth without overwhelming the scene. It’s one of those plants I recommend time and again because it’s so dependable, yet still manages to be eye-catching. Whether you’ve got a tricky corner that never sees sun or a refined woodland scheme in mind, Sea Heart is a plant that quietly elevates everything around it.

• Brunnera Sea Heart is a PBR-protected perennial with silver heart-shaped leaves and rich blue flowers in spring
• Thrives in shade or dappled shade and is ideal for woodland garden planting
• Requires moist, humus-rich, well-drained soil enriched with compost or organic matter
• Excellent for ground cover, borders, or as a contrasting foliage plant
• Tolerates frost, heat and humidity, and short dry spells once established
• Produces blue forget-me-not flowers in early spring, with foliage interest lasting into autumn
• Easy to maintain: water during dry periods, cut back in winter, and divide every few years
• Offers more heat tolerance and vigour than similar cultivars like Jack Frost
• Available from reputable nursery suppliers and garden centres
• A standout herbaceous perennial for adding reliable, long-lasting beauty to your shady garden

Brunnera Sea Heart excels in shade with moist, well-drained soil of any pH, and is hardy to –20 °C (–4 °F). Over 5–10 years, it forms a 30–45 cm (12–18 in) clump of handsome foliage, with pale blue flowers in mid-spring. Simple spring mulching, occasional division and slug vigilance ensure a long-lasting, low-maintenance feature in UK gardens.

Check out the RHS article here.

If you like this one, you’ll love Brunnera Dawson’s White. Click here to explore it.

For more information on perennials for your garden, please click here.

Q: What is Brunnera Sea Heart?

A: Brunnera Sea Heart is a standout herbaceous perennial prized for its silver heart-shaped leaves with striking bright green veining. A mutation of Brunnera macrophylla, this variety—also known as Siberian bugloss Brunnera macrophylla Sea Heart—produces delicate sprays of small, rich blue flowers in spring, resembling blue forget-me-nots. It thrives in shady gardens and is ideal for ground cover beneath trees or in woodland gardens. Its resilient, rhizomatous nature and vibrant foliage make it a reliable, long-lasting addition to any garden.

Q: Where should I plant Brunnera macrophylla Sea Heart?

A: Brunnera macrophylla Sea Heart prefers a shady or dappled shade spot, particularly in a woodland garden or beneath deciduous shrubs. It performs best in moist, well-drained soil rich in organic matter or compost. Avoid full sun, especially in hotter climates, as this can scorch its vibrant foliage. This herbaceous perennial works beautifully in shaded borders, underplantings, or as a gorgeous groundcover. Grouping several plants enhances the display of both flowers and foliage, creating a refined and naturalistic aesthetic.

Q: How do I care for Brunnera Sea Heart throughout the year?

A: Caring for Brunnera Sea Heart is straightforward. In spring, enjoy its blue flowers as new foliage emerges. During the growing season, ensure the soil remains evenly moist, especially during dry spells. In late autumn, cut back tired leaves to prepare for winter, and apply a generous mulch of compost or well-rotted organic matter. Come spring, new growth will reappear with renewed vigour. Feed in early spring with a balanced slow-release plant feed to support blooming and foliage colour. Remove spent flowers to keep the plant looking its best.

Q: Does Brunnera Sea Heart tolerate frost?

A: Yes, Brunnera Sea Heart is fully hardy in the UK and copes well with frost. This perennial dies back in autumn and enters dormancy over winter, with new growth emerging each spring. While mature plants are resilient, young plants may benefit from a protective mulch in their first winter. There’s no need to lift or move them, making it an excellent low-maintenance choice for shady gardens or exposed sites with cold winters.

Q: Is Brunnera Sea Heart suitable for containers?

A: Yes, Brunnera Sea Heart grows well in containers, provided the plant has ample space and moisture-retentive compost. Use a loam-based compost enriched with organic matter, and ensure the container has good drainage to prevent root rot. Place pots in a shady or lightly shaded area, away from direct sunlight. Feeding in spring and watering consistently will support vibrant foliage and flowers. Potted specimens are perfect for patios, courtyards, or shady balconies where ground planting isn’t possible.

Q: When does Brunnera Sea Heart flower?

A: Brunnera Sea Heart blooms in spring, typically from April to May. It produces sprays of small bright blue flowers above its emerging foliage, adding a delicate haze of colour to shaded borders. These flowers resemble blue forget-me-nots and provide early-season interest when few other plants are in bloom. While the flower display is charming, this variety is primarily grown for its stunning foliage, which remains attractive throughout the season.

Q: What makes Brunnera Sea Heart different from Brunnera Jack Frost?

A: While both are cultivars of Brunnera macrophylla, Sea Heart boasts thicker, more vibrant foliage and greater tolerance to heat and humidity than Jack Frost. The silver heart-shaped leaves of Sea Heart have a deeper texture with defined green veining, creating a bolder visual impact. It also resists leaf scorch better in warmer weather, making it ideal for sunnier corners of a shady garden. Both varieties produce similar blue flowers in spring, but Sea Heart offers improved vigour and a longer season of visual interest.

Q: Is Brunnera Sea Heart invasive?

A: No, Brunnera Sea Heart is not considered invasive. Though it is rhizomatous, its growth is well-mannered and clump-forming rather than aggressive. Over time, the plant may slowly expand, creating excellent ground cover in woodland or shady settings. If desired, it can be easily divided in early spring or autumn to control size or propagate new plants. Its neat habit and refined appearance make it ideal for both structured garden designs and informal borders.

Q: Can I divide Brunnera Sea Heart?

A: Yes, mature Brunnera Sea Heart can be divided in early spring or after flowering in autumn. Carefully dig up the plant and separate it into sections, ensuring each division has a portion of roots and healthy buds. Replant immediately into moist, enriched soil, and water thoroughly. Dividing not only helps rejuvenate older plants, but also allows you to propagate new ones for other parts of the garden. Apply a light feed after replanting to support establishment and new growth.

Q: Where can I buy Brunnera Sea Heart?

A: Brunnera Sea Heart is widely available in the UK from reputable garden centres, plant nurseries, and online retailers. Look for healthy potted plants during the spring planting season, or shop online for a broader selection and the convenience of delivery. As a PBR (Plant Breeders’ Rights) protected variety, always buy from trusted suppliers to ensure genuine stock. It’s a popular choice for shaded gardens, so availability is generally good throughout the growing season.