Jack Frost: Heart-Shaped Silver Leaves, Delicately Veined With Mint Green
Brunnera macrophylla ‘Jack Frost’, or more commonly called Jack Frost forms a clump of heart-shaped silver leaves that are delicately veined with mint green coloring. Sprays of gorgeous bright blue forget-me-not flowers appear May to June. This is an easy-to-grow perennial that performs well in all but the driest of shady conditions. It is an excellent for the woodland garden. ‘Jack Frost’ handles more direct sun that most other variegated types of Brunnera, though in hot-summer regions some afternoon shade is recommended to prevent leaf scorch.
At maturity this plant reaches a height of 12 to 15 inches (up to 18 inches when the slender bloomstalks are considered) and 18 inches wide. It prefers acidic soil, but is generally not fussy, it is tolerant of harsh winter weather, and tolerates poor soil fertility. Clumps are dense, so if you are planting more than one together, space the plants 18 to 24 inches apart to give them space to show off their nicely rounded form. The only requirements for success are moist, well-drained soil and planting in zones 3 to 8.
Jack Frost is a rhizomatous, clump-forming perennial that is primarily grown for its attractive basal foliage. The leaves are a very eye catching, and distinctive silvery white with green primary and secondary veins and a thin green rim around the leaf edges. The basal foliage forms a hosta-like mound of heart-shaped leaves (3 to 5 inches wide) which remain attractive throughout the growing season. Smaller stem leaves are elliptic. Tiny, forget-me-not-like flowers (light blue with yellow centers) in airy, branched cymes that rise above the foliage on slender stems that reach 18 inches in height.
How To Make Your Jack Frost Thrive
Plant this colorful perennial in light to dappled shade; avoid hot afternoon sun which will burn the leaves. It grows best in rich well-drained soil, but will tolerate sandy soils, and clay. Regular watering during dry weather will keep the foliage fresh all season long. Once Jack Frost is established it will survive infrequent watering during summer. Cut back in fall once the foliage becomes unsightly. Thick fleshy roots grow deep into the soil and will sprout new plants if they are broken.
General Jack Frost Information
Pests and Diseases
No serious insect or disease problems. Slugs and snails are occasional pests.
Divide healthy roots into small sections. This can often be done by hand; if the plant is tough, use a sharp knife to do this. When you divide the brunnera, do so gently, teasing out the roots instead of pulling them apart.
Plant in groups or mass as a ground cover; it is also excellent in borders, woodland gardens, naturalized areas, or along streams or ponds.
- Family: Boraginaceae
- Common Name: Jack Frost, sometimes Siberian bugloss
- Type: Herbaceous perennial
- Hardiness Zones: Zones 3 to 8
- Height: 1 to 1.5 feet
- Width: 1 to 1.5 feet
- Bloom Time: April to May
- Bloom Color: Blue
- Sun: Light shade to dappled shade
- Water: Medium to occasional watering
- Soil Type: Normal, sandy, or clay
- Soil pH: Neutral, alkaline, or acidic
- Maintenance: Low
- Tolerate: Rabbit
- Seasonal Interest: Distinctive foliage in spring and summer
Google – Jack Frost Photos
Flicker – Jack Frost Photos