perennial
Siberian bugloss 'Jack Frost'
Brunnera macrophylla 'Jack Frost'
Preview: plant data is awaiting horticulturist review. A professional horticulturist hasn't reviewed our plant table yet. Lists still follow fixed rules for zone, sun, pets, deer and invasive status.
Hardy in zones 3–8, Siberian bugloss 'Jack Frost' is a perennial. It grows 1–1.5 ft tall and 1.5–2 ft wide, so plant it 1.5 ft apart. Give it part shade to shade and average water. It flowers blue in April to May. In a FloraVista list it usually plays the filler role: a flowering plant that fills the middle or front of the bed. Deer usually leave it alone, and it is toxic to dogs and cats. Our rules leave it out of lists in Florida and the Gulf, Texas and the South-Central states and the Desert Southwest, where summer heat, humidity or mild winters hold it back even inside its zone range.
Facts from our plant table
- Botanical name
- Brunnera macrophylla 'Jack Frost'
- Plant type
- Perennial, herbaceous
- Hardiness zones
- 3 to 8
- Sun
- Part shade (2–4 hours); Shade (under 2 hours)
- Water
- Medium
- Soil
- Moist, humus-rich soil.
- Mature size
- 1–1.5 ft tall × 1.5–2 ft wide
- Spacing
- 1.5 ft apart (centre to centre)
- Growth rate
- Medium
- Bloom
- Apr–May · blue
- Roles in a bed
- Filler
- Styles
- classic, modern
- Deer resistance
- High: deer rarely eat it
- Pets
- Toxic to dogs and cats. Not on the ASPCA list; borage-family plants can contain pyrrolizidine alkaloids. Marked toxic as a precaution.
- Native to
- Not native to the US (or a garden hybrid)
- Pot size and price
- 1-gallon pot, typically $15–$25 (easy to find)
- Plant in
- Spring or Fall
- First-year watering
- Water deeply once or twice a week through the first growing season; keep soil evenly moist, not soggy.
- Pruning
- Remove flower stems after bloom; cut back scorched leaves.
Sources: ASPCA Toxic and Non-Toxic Plant List (from general knowledge; not re-checked unless verification is web-checked); Missouri Botanical Garden Plant Finder and grower tags; State extension service guidance and USDA PLANTS distribution maps; Rutgers NJAES Landscape Plants Rated by Deer Resistance; Invasive Plant Atlas of the United States and state noxious weed lists; Typical 2026 US garden-centre and big-box retail listings (estimate). Not yet reviewed by a horticulturist.
Guides that include this plant
- Deer-resistant plants for a part-shade bed in zone 5 (as a substitute)
- Deer-resistant plants for a part-shade bed in zone 6 (as a substitute)
- Deer-resistant plants for a part-shade bed in zone 7 (as a substitute)
- Deer-resistant plants for a part-shade bed in zone 8
- What to plant in a part-shade bed in zone 8
- What to plant in a shady bed in zone 4
- What to plant in a shady bed in zone 5 (as a substitute)
- What to plant in a shady bed in zone 7
Good companions
The plants our list engine most often puts in the same bed as Siberian bugloss 'Jack Frost', across the sun, zone, pet, deer and style combinations it fits.
- Lenten roseHelleborus × hybridusperennial · zones 4–9
- Bleeding heartLamprocapnos spectabilisperennial · zones 3–9
- Japanese painted fern 'Pictum'Athyrium niponicum 'Pictum'fern · zones 4–8
- Japanese sedge 'Ice Dance'Carex morrowii 'Ice Dance'ornamental grass · zones 5–9
- Autumn fernDryopteris erythrosorafern · zones 5–9
- Korean boxwood 'Wintergreen'Buxus sinica var. insularis 'Wintergreen'shrub · zones 4–9
If you can't find it
Substitutes our engine offers for Siberian bugloss 'Jack Frost': same role in the bed, passing the same rules.
- Japanese painted fern 'Pictum'Athyrium niponicum 'Pictum'zones 4–8 · flagged toxic to pets
- Autumn fernDryopteris erythrosorazones 5–9 · flagged toxic to pets
- Lenten roseHelleborus × hybriduszones 4–9 · flagged toxic to pets
- Variegated Solomon's seal 'Variegatum'Polygonatum odoratum 'Variegatum'zones 3–8 · flagged toxic to pets
How this page was made
This page was generated from this plant's record in FloraVista's plant table by fixed rules. The companions and substitutes come from the lists our rules engine composes. No named expert has reviewed this page.
Data status: the plant table is awaiting review by a horticulturist. Check each plant with a local nursery or extension office before you buy.
Sources
- Missouri Botanical Garden Plant Finder, state extension services and the USDA PLANTS database (zones, size, sun, water, bloom, native range)
- ASPCA toxic and non-toxic plant lists (dog and cat toxicity)
- Rutgers NJAES and regional extension deer-resistance ratings
- State noxious-weed and invasive-plant lists and the Invasive Plant Atlas of the US
- Typical US garden-centre listings (pot size and price band)
Generated . How FloraVista chooses plants