Jack Frost brunnera

Sun

Partial shade or bright shade; gentle morning sun is suitable where the soil stays moist. Avoid hot afternoon sun, especially in warmer climates.

Water

Keep the soil evenly moist but not waterlogged. Water deeply during dry spells, especially in the first growing season; established plants still tolerate drought poorly.

Soil

Humus-rich, moisture-retentive soil with good drainage. Tolerates clay improved with organic matter and a range from mildly acidic to mildly alkaline conditions.

Height

1-1.5 ft (0.3-0.45 m), including flower stems

Spread

1.5-2 ft (0.45-0.6 m)

Flowers

Small sky-blue flowers with pale centres in mid- to late spring.

Foliage

Large, heart-shaped, slightly rough leaves with a silver surface, green veins and narrow green margins. Leaves enlarge after flowering and die back for winter.

Growth

Moderate

Care needed

Low

• Pollinators
• Deer resistant
• Cold hardy
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   1.1 ft (0.32 m)

3. After 2 years

   1.1 ft (0.35 m)

4. After 3 years

   1.2 ft (0.38 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Growth rate

Moderate

• Plant with the crown at soil level and allow room for the mature clump.
• Water at soil level whenever the root zone begins to dry; do not let newly planted clumps dry out.
• Apply a thin layer of compost in spring; rich soil rarely needs additional fertiliser.
• Mulch with leaf mould or compost to conserve moisture, keeping it clear of the crown.
• Divide congested clumps in spring or early autumn, watering divisions until established.

Pruning. Cut spent flower stems back to the base after flowering if you do not want seedlings. Remove badly scorched or damaged leaves during the growing season, then clear dead foliage in late autumn or before new growth in spring.

Early spring

Remove old dead foliage before new shoots expand, and top-dress with compost.

Spring

Plant or divide clumps while the weather is cool, then water thoroughly.

Late spring

Remove faded flower stems to tidy the plant and limit self-seeding.

Summer

Check soil moisture during dry spells and water deeply; watch for leaf scorch.

Early autumn

Plant or divide where there is enough mild weather for roots to establish before winter.

Late autumn

Remove collapsed foliage if desired and check that wet soil or piled mulch is not covering the crown.

• Plant in repeated groups along a shady path, where the silver leaves make a clear, low edging.
• Combine with ferns and hostas for contrasting leaf shapes in a woodland border.
• Use beneath deciduous shrubs where spring light reaches the flowers and summer shade protects the foliage.
• Pair with dark-leaved heucheras to make the silver foliage stand out.

Garden styles it suits: Woodland, Cottage garden, English country, Blues and silvers, White garden and Pacific Northwest woodland.

Plant it with: Hostas, Japanese painted ferns, Hellebores, Heucheras, Astilbes and Snowdrops.

Wildlife: Spring flowers provide nectar and pollen for visiting bees and other small insects. The foliage is usually less attractive to deer and rabbits than many other shade plants, but browsing can still occur.

• Leaf scorch: brown, crisp edges usually indicate excessive sun, heat or dry soil. Water deeply, mulch and move the plant to a cooler, shadier position if necessary.
• Slugs and snails: young leaves may be eaten. Check after dark, remove pests and use barriers or labelled iron-phosphate bait where needed.
• Crown or root rot: persistent waterlogging can cause collapse. Improve drainage, keep the crown uncovered and replace badly rotted plants.
• Green-leaved reversions: occasionally a shoot loses its silver pattern. Remove that shoot at its point of origin so it does not dominate the clump.

Not known to be toxic to people, cats, dogs or horses. No part is recognised as a significant poisoning hazard, but it is not an edible plant and should not be deliberately eaten.

• Wood forget-me-not (Myosotis sylvatica)

  It has similar small blue flowers but much smaller, narrow, hairy green leaves rather than broad, silver, heart-shaped leaves.

• Lungwort (Pulmonaria species and hybrids)

  Many lungworts have silver-spotted or silver leaves, but their leaves are generally longer and narrower, and their larger, funnel-shaped flowers often change from pink to blue.

Brunnera honours Swiss botanist Samuel Brunner, macrophylla means large-leaved, and 'Jack Frost' refers to the foliage's frosted appearance.

Propagation. Divide established clumps in spring or early autumn, keeping roots and healthy buds on each division. Seedlings do not reliably retain the silver foliage of 'Jack Frost'; use division to keep the cultivar true.

Accepted botanical name

Brunnera macrophylla

In the US and Canada

Introduced in the lower 48 states.

Native range

North Caucasus, Transcaucasus and Turkey.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.