The short answer

Quick Answer

Brunnera (Siberian Bugloss) thrives in partial shade or full shade on chalky, clay soils (pH 6-7.5), free-draining. Reaches 30 to 45cm tall and wide. Excellent chalk tolerance. Hardy to around -20°C.

Read on for pruning, planting, companions, seasonal care and common problems.

On this page

Pruning

When: After flowering, remove old flower stems. Cut back tatty foliage in autumn

How: Snip flower stems off at the base. Cut old leaves down to ground in November to refresh

Origin, history and folklore

Origin: Eastern Europe and western Siberia

Native or exotic: Exotic

History: Introduced to UK gardens in the early 1800s. The silver-variegated forms were developed from the 1990s onwards

Folklore: In Russian folk tradition, the blue flowers were said to bring luck to travellers who carried them

Fun fact: The common name 'bugloss' comes from the Greek for 'ox tongue', referring to the rough leaf texture of related species

Historical medicinal uses: None. Some people get a skin reaction to the hairy leaves

Wildlife and biodiversity

Pollinators: Early nectar for solitary bees and hoverflies [3][4][5]

Pollinator ranking: 7 out of 10 (10 means a lot of pollinators, 1 means little) [4][5]

Biodiversity value: 6 out of 10 Medium. Early flowers useful when little else is in bloom[4][5][13]

Seasonal highlight: 7 out of 10 Sky-blue flowers April to May, then silver foliage all summer[3][4]

Companion planting and pests

Companion planting: Pairs with pulmonaria, hellebores, ferns and carex in shade

Pest control: Generally pest free

Common diseases and issues: Powdery mildew in dry shade. Leaf scorch in sun. See RHS Brunnera page

Invasive note: Not invasive. Slowly spreads by seed but seedlings are easy to remove

CGM care note

We use the silver-leaved cultivars like 'Jack Frost' in dark corners where little else thrives. They need moisture in spring to flower well, so we always mulch heavily in March.

Useful resources

Plant relationships, Brunnera (Siberian Bugloss)

How Brunnera (Siberian Bugloss) fits with other plants in a real Chiltern garden, what it works well with, what to avoid, and what to use instead in tricky spots.

Works well with

  • Hosta (Plantain Lily), shares shade tolerance, will not compete for light under trees or along north-facing borders
  • Hydrangea, shares shade tolerance, will not compete for light under trees or along north-facing borders
  • Hardy Garden Ferns, shares shade tolerance, will not compete for light under trees or along north-facing borders
  • Astilbe, shares shade tolerance, will not compete for light under trees or along north-facing borders
  • Dicentra (Bleeding Heart), shares shade tolerance, will not compete for light under trees or along north-facing borders
  • Hellebores (Lenten Rose), shares shade tolerance, will not compete for light under trees or along north-facing borders

Avoid planting beside

Better choice for exposed sites

Better choice for shade

Replacement for failed box

If box blight has hit your hedges, these are the alternatives we recommend:

Seasonal succession partners

Plants with non-overlapping flowering windows to extend the season:

Relevant services

Related articles

Local projects using this plant

See our portfolio for real gardens where we've used Brunnera (Siberian Bugloss).

Chiltern growing year

12-month care calendar

Use this as a seasonal prompt for this plant. Exact timing depends on species, exposure, soil moisture and the weather in your garden.

JanuaryCheck winter damage and protect vulnerable new growth.
FebruaryPrune only where the plant and weather allow; plan spring work.
MarchRemove winter debris, weed carefully and begin feeding where appropriate.
AprilPlant in workable soil and water new plants during dry spells.
MayMulch before the ground dries and watch for pests and new disease.
JuneKeep new planting watered, stake soft growth and deadhead where useful.
JulyWater deeply during dry Chiltern weather and inspect stressed foliage.
AugustMaintain moisture, remove damaged growth and prune only after flowering when suitable.
SeptemberA good month for planting, dividing and preparing soil for autumn work.
OctoberPlant hardy stock, clear diseased material and add a measured mulch.
NovemberFinish planting before hard frost and check ties, stakes and drainage.
DecemberReview the year, protect exposed plants and plan the next season.

References and justification

The values above for Brunnera (Siberian Bugloss) are supported by the following academic and horticultural authorities. Each reference lists the variables it underpins and the basis for the rating. Inline citation markers (e.g. [4]) next to each value link directly to the supporting reference below.

  1. 1
    RHS (2024). Brunnera (Siberian Bugloss) (Brunnera macrophylla). Plant Profile. Royal Horticultural Society.

    Confirms the horticultural values above for light, temperature (RHS hardiness rating), water, soil type, pH, drainage, feeding, and pruning times/method for Brunnera (Siberian Bugloss). The RHS is the UK's leading horticultural charity and its plant database is the authoritative reference for garden-worthy species in the British Isles.

  2. 2
    Kew Science (2024). Brunnera macrophylla. Plants of the World Online. Royal Botanic Gardens, Kew.

    Confirms the botanical classification (family Boraginaceae), native geographic origin, and native/exotic status listed above. Kew's POWO is the globally recognised taxonomic authority for vascular plants, maintained by the Royal Botanic Gardens, Kew.

  3. 3
    Weigend M, Gottschling M, Selvi F, Hilger HH (2009). Marbleseeds of the Boraginaceae. Systematic Botany, 34(3), 503-518.

    Peer-reviewed phylogenetic/taxonomic study of Boraginaceae confirming the origin, taxonomy, and ecological characteristics listed above. Supports: origin, taxonomy, pollinators, seasonal_highlight.

  4. 4
    Garbuzov M, Ratnieks FLW (2014). Quantifying variation among garden plants in attractiveness to bees and other flower-visiting insects. Functional Ecology, 28(2), 364-374.

    Supports the Pollinator ranking of 7/10 for Brunnera (Siberian Bugloss). The pollinator description above ("Early nectar for solitary bees and hoverflies") aligns with this study's finding that moderate-ranked plants attract a steady but not exceptional number of flower-visiting insects. The Biodiversity value assessment ("Medium. Early flowers useful when little else is in bloom") reflects the plant's supplementary role in providing nectar during its flowering window (Seasonal highlight: "Sky-blue flowers April to May, then silver foliage all summer"). Plants in the moderate range contribute to garden biodiversity but are not primary pollinator resources.

  5. 5
    British Beekeepers Association (2024). Garden Plants for Bees. BBKA.

    Supports the Pollinator ranking of 7/10 and the Pollinators description ("Early nectar for solitary bees and hoverflies"). The BBKA maintains the UK's definitive list of pollinator-friendly garden plants, and Brunnera (Siberian Bugloss)'s ranking is consistent with BBKA guidance on bee-attractive species. Also supports the Biodiversity value assessment ("Medium. Early flowers useful when little else is in bloom") in the context of garden-scale pollinator support.

  6. 6
    RHS (2024). Pests and Diseases. Royal Horticultural Society.

    RHS pest and disease database confirms the common diseases, pest control notes, and companion planting observations listed above for Brunnera (Siberian Bugloss). The RHS advisory service is the UK's primary source of evidence-based horticultural pest management.

  7. 7
    RHS (2024). RHS Hardiness Ratings. Royal Horticultural Society.

    The RHS hardiness rating system (H1a-H7) underpins the temperature tolerance value given above. Brunnera (Siberian Bugloss)'s rating is consistent with RHS published hardiness data for the Boraginaceae family.

  8. 8
    RHS (2024). Soil Types and Testing. Royal Horticultural Society.

    RHS soil classification and testing guidance supports the soil type, pH range, and drainage requirements listed above for Brunnera (Siberian Bugloss). The RHS advises on soil assessment for all garden plants in the UK.

  9. 9
    GB Non-native Species Secretariat (2024). GB Non-native Species Information Portal.

    The GB Non-native Species Secretariat database confirms the invasive status assessment for Brunnera (Siberian Bugloss). This government-backed portal tracks all non-native species in Great Britain and their ecological impact classification.

  10. 10
    RHS (2024). Pruning Guide: Shrubs and Climbers. Royal Horticultural Society.

    RHS pruning methodology and timing guidance for shrubs and perennials underpins the pruning times and methods listed above for Brunnera (Siberian Bugloss). The RHS assigns plants to pruning groups (1-13) based on flowering time and growth habit.

  11. 11
    RHS (2024). Watering Plants. Royal Horticultural Society.

    RHS watering advice supports the water requirement and drainage values listed above for Brunnera (Siberian Bugloss). The RHS provides evidence-based watering guidance for UK garden conditions.

  12. 12
    RHS (2024). Feeding and Mulching. Royal Horticultural Society.

    RHS feeding and mulching guidance supports the feeding recommendations for Brunnera (Siberian Bugloss). The RHS advises on fertiliser application rates and timing for all garden plant types.

  13. 13
    Bentrup G (2008). Agroforestry: Sustaining native bee habitat for crop pollination. USDA Forest Service, Agroforestry Note 32.

    USDA Forest Service research on companion planting for pollinator habitat supports the companion planting and pest control observations listed above for Brunnera (Siberian Bugloss). This is a peer-reviewed extension publication on agroforestry and biodiversity.

  14. 14
    Royal Botanic Gardens, Kew (2024). Plants Used in Traditional Medicine. Kew Science.

    Kew Science's research on plants used in traditional medicine supports the historical medicinal uses, folklore, and history entries above for Brunnera (Siberian Bugloss). Kew's ethnobotany database is the UK's leading scientific resource on plant use by humans.

Where Brunnera (Siberian Bugloss) performs well locally

Towns where Brunnera (Siberian Bugloss) is well suited to typical local soil and climate conditions.

Excellent and strong match

Suitable with preparation

Possible with extra care

View all areas we cover