How to Grow Siberian Bugloss

brunnera flowers

The Spruce / Evgeniya Vlasova

The Brunnera macrophylla plant goes by several common names, including Siberian bugloss, false forget-me-not, brunnera, large-leaf brunnera, and heartleaf. The common name "bugloss" is derived from the Greek words for "ox" and "tongue," as the leaves are thought to resemble an ox tongue. The bright blue flowers may have you doing a double-take with their resemblance to the blooms of the real forget-me-not. Whatever you call it, this long-lasting and low-maintenance species has always been a popular shade plant.

This clumping perennial spreads from rhizomatous roots and has dark-green heart-shaped leaves. Small blue flowers with white centers rise on stems in spring; the bloom period lasts for about four weeks. Although Siberian bugloss is a slow grower, the species will eventually spread out and make a nice ground cover. The flashier variegated varieties are a bit slower to fill out, but provide interest and color all season. Siberian bugloss is generally planted from potted nursery plants in early spring, as soon as the ground can be worked. It grows rather slowly, which is an advantage since it doesn't demand frequent division and rarely becomes invasive.

Botanical Name Brunnera macrophylla
Common Names Siberian bugloss, brunnera, large-leaf brunnera, heartleaf, false forget-me-not
Plant Type Herbaceous, perennial
Mature Size 12–18 in. tall; 18–30 in. spread
Sun Exposure Full, partial, shade 
Soil Type Medium moisture, well-drained 
Soil pH Acidic, neutral to acidic, alkaline 
Bloom Time Spring 
Flower Color Blue
Hardiness Zones 3–8 (USDA)
Native Area Asia, Europe
closeup of brunnera flowers
The Spruce / Evgeniya Vlasova
brunnera growing by rocks
The Spruce / Evgeniya Vlasova
brunnera leaves
The Spruce / Evgeniya Vlasova

Siberian Bugloss Care

Siberian bugloss is best planted in a part-shade to a full-shade location in a rich soil that has excellent drainage. In a good environment, this is a largely care-free plant that requires little more than division every three or four years.

Siberian bugloss is often planted in shade gardens, woodland settings, and near ponds. It can make a great ground cover and looks beautiful lining a path or border, although it can take a while to fill in.

Since deer do not often bother this plant, it makes a nice alternative to hostas. Companions with different textures and leaf shapes include hellebores, iris, hostas, bleeding heart, geraniums, and even late-blooming daffodils. Since Siberian bugloss prefers cool, moist shade, slugs may become a problem, but varieties with thicker leaves are rarely bothered.

Light

Siberian bugloss prefers shady conditions, though it can survive in full sun if it gets more moisture. But the variegated leaves can easily burn in direct sunlight and plants may go dormant in extremely sunny conditions.

Soil

This plant is not too particular about soil pH, but it does like rich, moist soil. Lots of organic matter and organic mulch will help it become established quickly and keep it growing well. Siberian bugloss does not tolerate dry soils.

Water

Keep new plants well watered. While Siberian bugloss plants prefer constant moisture, they will become more drought-tolerant once they are established. Mulching will help maintain the cool, moist soil that Brunnera prefers.

Temperature and Humidity

Though rated for hardiness zones 3 to 8, Siberian bugloss prefers regions with cool summers. You may have trouble with it in zones that have especially hot and humid summer conditions (zones 7 to 8).

Fertilizer

These plants prefer rich soil but do not require supplemental feeding, as long as the soil is not too poor or dry.

Siberian Bugloss Varieties

The species form of Brunnera macrophylla, with solid green leaves, is readily available. It has lovely sprays of blue flowers and is an extremely tough plant. In addition, there are several cultivars available:

  • 'Diane's Gold' has golden-yellow leaves and blue flowers.
  • 'Hadspen Cream' has extra-large leaves with irregular white outer margins.
  • 'Jack Frost' has silvery leaves with green veins.
  • 'Langtrees' (aka 'Silver Spot') is a very hardy plant with leaves that are dotted with silver.
  • 'Looking Glass' has silver leaves that look almost metallic.
  • 'Queen of Hearts' is an updated version of 'Jack Frost', this cultivar boasts larger, bolder silvery leaves.
  • 'Alexander's Great' boasts jumbo-sized dark green leaves veined in silvery-white.

Pruning

The older leaves may start to get tattered and can be cut back during the growing season to encourage new leaves to fill in. Don't cut the whole plant back to the ground in the fall—the leaves will help protect the crown during winter and you can easily clean away the old foliage in the spring when the new leaves begin to emerge.

If you do not want your plants to self-seed, deadhead as the flowers start to fade. If you would like to collect the seed to sow, allow the flowers to dry slightly, then cut and let them finish drying in a paper bag. The seeds will fall off as the flowers dry.

Propagating Siberian Bugloss

The best means of propagation is to simply dig up an established clump in early spring, divide it into healthy segments, and replant. Siberian bugloss can be short-lived, and dividing your plants every three to five years will keep them around longer.

Although the named cultivars may self-seed, the volunteers usually do not grow true to the parent plant and are best weeded out if you want to preserve the look of the parent. For example, volunteer seedlings of variegated plants often have solid green leaves.

Growing in Pots

This plant can be a great choice for containers that are placed in partial or full shade. The variegated leaf varieties will make a nice filler throughout the season. Many are hardy enough to remain in containers throughout the winter, with a little extra protection.