How to Grow and Care for Siberian Bugloss

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. This long-lasting and low-maintenance species has always been a popular shade plant.

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.

Light

Siberian bugloss prefers shady conditions, though it can survive in full sun if it gets more moisture. 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.

Types of Siberian Bugloss

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’ is a patented cultivar with wilvery 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.
• ‘Sterling Silver’ is similar to ‘Looking Glass’ with the same silver colored, heart-shaped foliage, but with larger leaves.

Pruning

If the foliage starts to look unsightly during the summer, cut remove them to encourage new leaves to fill in. If you do not want your plants to self-seed (Siberian bugloss easily reseeds itself), deadhead as the flowers start to fade.

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.

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. Keep in mind that some varieties are protected by a plant patent and their propagation is prohibited.

1. Lift the entire plant out of the ground with a shovel. Shake off any excess soil, which helps to separate the clump into smaller sections. Remove any diseases or weak roots.
2. Divide the healthy roots into small sections using your hands or a sharp knife.
3. Cut down the leaves to about 6 inches to prevent the plants from toppling over when you plant them.
4. Plant each section in prepared garden soil at the same depth as the original plant. Water them well and keep the soil evenly moist, watering every couple of days until you see new growth emerge.

Growing Siberian Bugloss from Seed

Although the plant may self-seed, the volunteers from cultivars 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. Therefore it is not recommended to grow it from seeds that you have collected yourself, and seeds are not commonly available from seed companies.

Potting and Repotting

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.

Use a pot that is large enough to accommodate the root system, plus a couple of inches to allow for growth. Make sure the container has large drain holes. Fill the pot with a quality potting mix, which usually comes with slow-release fertilizer.

Like all container plants, Siberian bugloss needs more watering when grown in containers.

When the roots grow out of the drain holes, or the plant becomes root-bound, it’s time to transplant it to a larger pot.

Overwintering

All plants, whether planted in garden soil or in containers, benefit from a thick layer of mulch during the winter months. Siberian bugloss is a hardy plant and winterization is only required when you are growing it in containers because the winter freeze can kill the roots. In climates with extended winter frosts, cover the container with a double layer of burlap and bubble wrap.

Common Pests & Plant Diseases

Since Siberian bugloss prefers cool, moist shade, slugs may become a problem, but varieties with thicker leaves are rarely bothered. Otherwise, Siberian bugloss free of serious pests and diseases.

How to Get Siberian Bugloss to Bloom

Failure to bloom may be due to too much sunlight, which causes the plant to go dormant prematurely.