Prunella, Brunelle : plant, cultivate

Description and Botany

The Prunella, also known as self-heal, is a semi-evergreen perennial from the Lamiaceae family, which includes lamiums, sages, mints, and thymes. The genus Prunella comprises seven perennial species that grow in dry meadows and rocky, mountainous areas across Europe, Asia, Africa, and North America. The Prunella grandiflora, the large-flowered self-heal and its cultivars, is the most common species found in our gardens. There is also Prunella vulgaris, the common self-heal, which has medicinal properties. It is typically found in fields or pastures.

Prunella grandiflora, botanical illustration, 1817

From a running stump, the plant develops a low, compact, and ramified herbaceous tuft, 15 to 30 cm in height when in bloom. The plant eventually forms a spreading tuft. This ground cover tends to spread over time through creeping stems, leafy stolons that root upon contact with the soil, making it ideal for rockeries, sunny borders, or even in window boxes and pots.

The square stems, whether upright or prostrate, bear semi-evergreen foliage composed of opposite, ovate leaves, 3 cm wide, entire or dentate, petiolate, strongly veined, and rough. They are a beautiful dark green. Very hardy, this foliage disappears in excessively harsh winters.

The flowering of Prunella extends from May to September. Short, compact flower spikes rise well above the foliage. They bloom as small tubular, bilabiate flowers measuring 1 to 3 cm, grouped in whorled spikes at the tips of the stems in shades of lavender blue, lilac, pink, or pure white. The corolla is shaped like a wolf’s mouth, consisting of two fused lips, with the upper lip incurved like a galea and the lower lip resembling a finely dentate tongue. They are surrounded by brown bracts. They resemble sage flowers.

Nectariferous and melliferous, they attract bumblebees, bees, and butterflies.

The fruits are slightly sticky achene, meaning they are divided into four equal parts. Once ripe, they are easily dispersed and are appreciated by certain birds.

Prunella vulgaris and Prunella laciniata

Main species and varieties

Prunella grandiflora Freelander Blue - Self-heal

An excellent hardy and robust blanket bog loaded with deep and bright violet-blue flowers from the very first year..

• Flowering time June to September
• Height at maturity 15 cm

See the product sheet

Prunella webbiana Rosea - Self-heal

An even more vigorous hybrid! This slightly taller variety is ideal for rockeries, in borders, and at the front of sunny flower beds.

• Flowering time July to September
• Height at maturity 25 cm

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Prunella grandiflora Bella Deep Rose - Self-heal

Here is an intense pink version of the wild type. This flower is perfect for blanket bog, in borders, in rockeries, or even in window boxes and pots.

• Flowering time August to October
• Height at maturity 15 cm

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Prunella grandiflora Pink Loveliness - Self-heal

A soft pink version of the wild type with its light lilac flowers. It is ideal for rockeries or in sunny borders.

• Flowering time August to October
• Height at maturity 15 cm

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Prunella grandiflora Altenberg Rosa - Self-heal

This beautiful improvement of the wild type displays spikes of delicate blue-mauve flowers. A wonderful blanket bog that requires very little maintenance.

• Flowering time August to October
• Height at maturity 20 cm

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Prunella grandiflora White Loveliness

This flower offers small spikes of tiny white flowers all summer long, contrasting with its beautiful fir green foliage.

• Flowering time August to October
• Height at maturity 15 cm

See the product sheet

Planting of Prunella

Where to plant the self-heal?

Prunella is an easy-going montane perennial, better resistant to cold (it is hardy below -15°C) than to drought during its flowering period. As it requires constant moisture in summer, it will struggle to grow in a Mediterranean climate, which is too dry and hot.

It thrives in full sun or partial shade in cool but well-drained soil. It tolerates full sun in sufficiently cool soil. It will flourish more in humus-rich soil, although it accepts poor, even calcareous, soils. It will reach its full potential in a partially shaded spot, such as under trees or bushes, and remains cool in summer.

This vigorous ground cover plant helps limit the spread of adventive plants in less-trodden areas of the garden. The self-heal can be mowed like a lawn after flowering.

It adorns borders, rockeries, or even window boxes and pots. It also allows for quick colonisation of shrub beds.

Prunella grandiflora (© Udo Schmidt)

When to plant the self-heal?

Planting of self-heal is done in autumn from September to November or in spring from March to April, outside of frost and drought periods.

How to plant it?

In open ground

Count about 5 buckets per m² to create a beautiful flowering ground cover and cover a nice area.

• Dig a hole three times wider than the root ball
• Add a few handfuls of sand and gravel to ensure good drainage
• Add a bit of compost or potting soil to the planting hole if the soil is too poor
• Place the root ball in the centre of the hole
• Fill in, firm down with your hand, and water generously
• Mulch with a mineral mulch (gravel, pumice, slate, terracotta shards…)

In pots

Prunella enjoys being in pots (about 30 cm in diameter) and window boxes in a substrate that is sufficiently draining to avoid stagnant moisture at the roots.

• At the bottom of a drainage hole pot, spread a good layer of drainage (gravel or clay balls)
• Plant in a mixture of potting soil and compost
• Mulch and water regularly

Cultivation and maintenance

Self-heal requires little care. In the first year following planting, water regularly, as it needs water to establish well. Afterwards, it can tolerate light and temporary drought. Mulch the soil with mineral mulch to reduce watering.

Fertilise occasionally with a handful of compost or other organic fertiliser at the base of the plant.

Remove faded flowers after flowering.

On large areas, mow after flowering to thicken the foliage.

Clean the clump at the end of winter and, if you wish to limit its spread, pull out the excess runners.

In pots, ensure to keep the substrate moist but not waterlogged: allow the compost to dry on the surface between waterings. Twice during the growing season, enrich the soil with fertiliser for flowering plants to encourage flowering and keep it vigorous.

Never diseased, this plant is, however, vulnerable to slugs and snails: follow our advice to protect its spring foliage.

Multiplication

Prunella tends to layer spontaneously. In spring or early autumn, you can take rooted runners to propagate the plant.

• With a spade, separate stems connected to the mother plant
• Unearth the leafy runners
• Replant immediately in moist soil, in a pot or directly in the ground

Associate

With its semi-evergreen foliage depending on the climate, Prunella adorns cool areas and slightly neglected corners of the garden. It is ideal for filling the space left at the base of trees and bushes, in flower beds, semi-shaded borders, and sufficiently cool rockeries.

It forms a low ground cover that is easy to integrate at the front of flower beds to create ribbons or in small touches, in front of heucheras or perennial geraniums like the perennial geranium ‘Rozanne’ which produces carpets of blue flowers from late spring until autumn without interruption.

It will edge a flower bed alongside easy-to-grow perennials such as Nepeta ‘Six Hill Giant’ and Phlox paniculata, as well as alchemilla ground covers like Caucasian alchemilla which flowers at the same time.

Under trees or bushes, Brunella is welcome among other ground cover perennials such as Bugle (the Ajuga ‘Atropurpurea’, ‘Princess Nadia‘), Asarum, with its heart-shaped foliage, corydalis, nodosum geraniums, and Vinca minor. Lamiums (Lamium maculatum ‘White Nancy’) or even tiarellas and heucherellas will also make good companions, with beautiful decorative and colourful foliage.

It forms lovely cushions at the base of larger plants, especially at the foot of roses.

It will also create pretty associations with alpine plants such as alyssum, Dianthus erinaceus, or the perennial geranium cinereum.

Did you know?

The leaves and flowering tops of Prunella vulgaris possess therapeutic, astringent, haemostatic, and vulnerary properties (for treating wounds). This medicinal plant is still used today. It contains, among other things, polysaccharides (prunelline), known for boosting the immune system. It also has digestive properties and can be used in infusions, decoctions, or mother tinctures. The leaves have a slight bitter taste that can enhance a salad.