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Brunnera
Brunnera macrophylla
Also called siberian bugloss
Brunnera blooms from April through May.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Brunnera
Plant it in part shade. It prefers moderate water. It is hardy in USDA zones 3–8. Expect it to reach about 16 in tall and 20 in wide at maturity, in roughly 2 years (not yet checked).
No toxicity note is on file for Brunnera. That is not a clearance: check its safety for people and pets before planting.
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Brunnera
Plant Brunnera in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 5, the middle of its hardy zones 3 to 8, spring means April to June and fall means August or September. Once settled, it blooms from April to May.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 5, the middle of this plant's hardy range, start with zone 5 in April. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Brunnera get?
16 intall5 ft 7 inan adult20 inwideSee Brunnera in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Brunnera
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Brunnera about 20 in apart, center to center, so each plant has room to reach its full width.
Add Brunnera to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Brunnera's height, spread, hardiness zones, sun and trait tags were checked against 10 published sources on July 30, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- NC State ExtensionPlant Toolboxheight, spread, hardiness zones, sun, years to mature size and trait tags
- Perennials.com (Heritage Perennials)Heritage Perennials (perennials.com)height, spread, hardiness zones, sun, years to mature size and trait tags
- University of Wisconsin HorticultureWisconsin Horticulture, Division of Extension (University of Wisconsin...height, spread, hardiness zones, sun, years to mature size and trait tags
- Fine GardeningPlant Guideheight, spread, hardiness zones, sun and years to mature size
- hoffienursery.comHoffie Nurseryheight, spread, hardiness zones, sun and trait tags
- Missouri Botanical GardenPlant Finderheight, spread, hardiness zones, sun and trait tags
- babikow.comBabikow Wholesale Nurseryheight, spread, hardiness zones and trait tags
- RHSheight, spread, sun and years to mature size
- avantgardensne.comAvant Gardenshardiness zones, sun and trait tags
- heritageflowerfarm.comHeritage Flower Farmhardiness zones
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about Brunnera
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note. A note reports what its source says; where that differs from a fact above, the fact above is this entry's stored value, and its mark says whether it has been checked.
Worth knowing
Though named for its blue forget-me-not flowers, Brunnera is grown mainly for bold heart-shaped leaves; cultivars like 'Jack Frost' hold frosted silver foliage from spring into fall. per NC State
Warm-end zone limit
Very cold hardy to zone 3, but the warm limit is soft: NC State lists zones 3 to 8, Chicago Botanic caps it at 7, since summer heat sets it. per NC State and Chicago Botanic
Scorches in sun or drought
In hot sun or dry soil the leaves scorch and edges brown; scorched plants can be cut back and will reflush from the crown. per Wisconsin
Deer and rabbit resistant
Reliably deer and rabbit resistant: the coarse, hairy, textured leaves deter browsing. per NC State
Main pest is slugs
Largely pest-free; the one regular nuisance is slugs and snails, drawn by the same cool, moist shade the plant favors. per RHS
Early nectar for bees
The early spring blue flowers draw bees and also butterflies, a modest early-season nectar source. per Chicago Botanic
What pairs well with Brunnera
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Rhododendron
Shares part shade and moderate water; overlaps, then carries the display into early summer; evergreen, so the bed keeps its shape through winter; both offer pollinator forage.
Wishbone Flower
Shares part shade and moderate water; blooms in early summer as this one finishes; both offer pollinator forage, in different months; lower at 10 in, for the front of the border.
Snowdrop
Shares part shade and moderate water; blooms in late winter, before this one opens; both offer pollinator forage, in different months; lower at 5 in, for the front of the border.
Japanese Stewartia
Takes part sun to part shade and moderate water; blooms in early summer as this one finishes; both offer pollinator forage, in different months; its white flowers settle the blue.
Goatsbeard
Shares part shade and moderate water; blooms in early summer as this one finishes; taller at 4 ft, for the layer behind it; both offer pollinator forage, in different months.
Meadow Rue
Shares part shade and moderate water; blooms in early summer as this one finishes; both offer pollinator forage, in different months; taller at 4 ft, for the layer behind it.
Beautyberry
Takes part sun to part shade and moderate water; blooms in early summer as this one finishes; both offer pollinator forage, in different months; taller at 5 ft, for the layer behind it.
Camellia
Shares part shade and moderate water; blooms in midwinter, before this one opens; both offer pollinator forage, in different months; evergreen, so the bed keeps its shape through winter; they only overlap in zones 7 to 8.
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Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.