Siberian bugloss 'Jack Frost'
Brunnera macrophylla 'Jack Frost' · Boraginaceae Popular
Heart-shaped silver leaves veined in green stay handsome from spring to frost. Sprays of tiny forget-me-not-blue flowers hover above them in spring.
- Size
- 16 in tall, 18 in wide
- Zones
- 3 to 8
- Light
- Part shade to shade
- Flowers
- Late April to late May
- Pets
- No toxicity recorded
- Job in a bed
- Edging
A bed built around Siberian bugloss 'Jack Frost'
The planner designed this bed around Siberian bugloss 'Jack Frost' when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, part shade. It chose the other plants from the 513 that suit those conditions, and says below why Siberian bugloss 'Jack Frost' stands where it does.
The plants
- 1 Siberian bugloss 'Jack Frost' × 3, blue
- 2 Moor grass 'Greenlee' × 5, tan
- 3 Creeping phlox 'Sherwood Purple' × 7, purple
- 4 Turtlehead 'Hot Lips' × 5, pink
- 5 Log fern × 3, dark green leaves
- 6 White bleeding heart × 1, white
- 7 Hardy cyclamen × 7, pink
- 8 Grecian windflower × 12, blue
Why this plant
- The only bold leaves here. The rest are fine and medium. A change of leaf keeps plants distinct when nothing is in flower.
- The only airy sprays. The others are spires, dense clusters, bells and others. Shape reads at a distance, where colours blur.
Why here
- In the middle. At 16 in it is the step between moor grass 'Greenlee' (12 in) in front and log fern (3½ ft) behind: each is seen over the one before.
- A step in the back row. Next to white bleeding heart (2½ ft) and log fern (3½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for six weeks. From late April to late May.
- Part of the bed's peak. With creeping phlox 'Sherwood Purple', white bleeding heart and Grecian windflower in early May: 4 kinds at once. No week has more.
Planned as an English border: 5 of the 6 groups (83%) are drifts, longer along the bed than they are deep. The front edge is finished with creeping phlox 'Sherwood Purple' and moor grass 'Greenlee'. The most in flower at one time is 4 kinds, in early May.
The planner's own design check: 14 Excellent, 3 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where Siberian bugloss 'Jack Frost' goes in a border
At 16 in it belongs at the front of a bed. In the planner's ten height classes it is short (12 to 18 in).
Its job: edging. A low, neat plant used in short runs of three or five along the front to finish the edge (or, in a formal bed, in one even row).
Silver leaves reflect what light there is and make a dark corner glow. The blue spring flowers are a bonus; the foliage is the reason to grow it. Repeat it along the front of a shady bed as a unifying thread.
- Silver foliage to light up shade
- Edging a shady path
- A spring partner for bulbs and bleeding heart
What to plant with Siberian bugloss 'Jack Frost'
Plants recorded as good partners for it, and what each pairing does:
- Bleeding heart: in flower together for five weeks, from early May; medium leaves against its bold ones; tall enough (2½ ft) to stand behind it.
- Lenten rose: in flower together for three weeks, from late April.
- Japanese painted fern: its silver leaves are a setting for the flowers, before and after; fine leaves against its bold ones; happy in the same moist soil.
Questions about Siberian bugloss 'Jack Frost'
Does Siberian bugloss 'Jack Frost' need sun or shade?
Siberian bugloss 'Jack Frost' grows in part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light).
It wants soil that stays evenly moist, rich in organic matter, and a good soak in dry spells.
What zones does Siberian bugloss 'Jack Frost' grow in?
USDA zones 3 to 8. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does Siberian bugloss 'Jack Frost' flower in my zone?
In zone 5 it flowers late April to late May. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 3 | Early May to mid June |
|---|---|
| Zone 4 | Early May to early June |
| Zone 5 | Late April to late May |
| Zone 6 | Mid April to late May |
| Zone 7 | Mid April to mid May |
| Zone 8 | Early April to early May |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should Siberian bugloss 'Jack Frost' be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.
It grows 16 in (40 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many Siberian bugloss 'Jack Frost' plants do I need?
At 18 in apart, set out in staggered rows:
- 5 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 17 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as runs of three or five along the front (or one even row, in a formal bed).
In the bed above, the planner used three in one group.
Is Siberian bugloss 'Jack Frost' poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat Siberian bugloss 'Jack Frost'?
Mostly not. NC State lists it as resistant to deer and rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What flowers after Siberian bugloss 'Jack Frost'?
Siberian bugloss 'Jack Frost' is over by late May. These start as it finishes and carry the same spot on, so it never goes flat:
- Lady's mantle: from late May to early July, 18 in tall.
- Astilbe: from late June to mid July, 24 in tall.
- Cranesbill 'Rozanne': from early June to early October, 18 in tall.
What does Siberian bugloss 'Jack Frost' look like in winter?
Siberian bugloss 'Jack Frost' dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.
Is Siberian bugloss 'Jack Frost' good for bees and butterflies?
Siberian bugloss 'Jack Frost' is visited by pollinators and bees.
More Brunnera
- Brunnera 'Alexander's Great' Brunnera macrophylla 'Alexander's Great'
- Brunnera 'Looking Glass' Brunnera macrophylla 'Looking Glass'
- Siberian bugloss Brunnera macrophylla
In these guides
- Deer-resistant plants for shade
- Rabbit-resistant plants
- Pet-safe plants for shade
- Plants for bees
- Plants with blue flowers
- Silver and grey-leaved plants
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8
Every fact on record
- Type
- Perennial
- Size
- 16 in (40 cm) tall, 18 in (45 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Short (12 to 18 in)
- Place in the bed
- Front
- Flowers
- Late April to late May; airy sprays; blue
- Leaves
- Bold texture, herbaceous; silver
- Shape
- Mounding, clumping
- Hardy in
- USDA zones 3 to 8
- Light
- Part shade, shade
- Soil
- Rich, evenly moist
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Boraginaceae
- Comes from
- Turkey, North Caucasus, Transcaucus
- Attracts
- Pollinators, bees
- Stands up to
- Deer, rabbits
Checked against NC State Extension and VASCAN (plants of Canada). Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.