Prunella, Selfheal: Planting and Growing

Description and botany

The Prunella, also known as self-heal, is a semi-evergreen perennial from the Lamiaceae family, like deadnettles, sages, mints and thymes. The Prunella genus includes seven perennial species growing in dry meadows, rocky and mountainous areas of Europe, Asia, Africa and North America. Prunella grandiflora, the large-flowered self-heal and its cultivars, is the most common species in our gardens. We also find Prunella vulgaris, the common self-heal, which has medicinal properties. This one is more likely to be found in fields or pastures.

Prunella grandiflora, botanical plate, 1817

From a running stump, the plant develops a low, compact and ramified herbaceous clump, 15 to 30 cm high in flower. The plant eventually forms a carpeting clump. This ground cover tends to spread over time by means of creeping stems, leafy stolons, which root upon contact with the soil, making it ideal for rockeries, sunny borders or even planters and pots.

The square, erect or prostrate stems 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 harsh winters.

The flowering of Prunella lasts from May to September. Short, compact flower spikes stand well above the foliage. They bloom as small tubular, bilabiate flowers 1 to 3 cm, gathered in whorled spikes at the ends of stems in shades of lavender blue, lilac, pink or pure white. The corolla is shaped like a snapdragon, consisting of 2 fused lips, the upper one incurved like a galea and the lower lip resembling a finely toothed 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 tetraachenes, meaning they are divided into 4 equal parts. Once mature, they are easily dispersed and are appreciated by some birds.

Prunella vulgaris and Prunella laciniata

Main species and varieties

Prunella grandiflora Freelander Blue - Self-heal

An excellent hardy ground cover plant, laden with deep, luminous violet-blue flowers from the 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, borders and 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 selfheal is perfect as ground cover, in borders, rockeries, or even in planters and pots.

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

See the product sheet

Prunella grandiflora Pink Loveliness - Self-heal

A soft pink version of the wild type with its pale lilac flowers. Ideal for rockeries or 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 on the wild type displays spikes of delicate blue-mauve flowers. A wonderful low-maintenance ground cover plant.

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

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Prunella grandiflora White Loveliness

This selfheal produces small spikes of white flowers all summer long, contrasting beautifully with its fir-green foliage.

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

See the product sheet

Planting Prunella

Where to plant selfheal?

Prunella is an easy-going montane perennial, more resistant to cold (it is hardy beyond -15°C) than to drought during flowering. As it requires constant moisture in summer, it will be difficult to grow in Mediterranean climates, which are too dry and hot.

It grows in full sun or partial shade in fresh but well-drained soil. It tolerates full sun if the soil remains sufficiently moist. It thrives best in humus-rich soil, though it will tolerate poor, even chalky soils. It will truly flourish in a partially shaded spot, under trees or bushes for example, where it stays cool in summer.

This vigorous groundcover plant helps suppress the spread of adventives in less-trodden areas of the garden. Selfheal can be mown like grass after flowering.

It dresses up borders, rockeries, or even planters and pots. It also quickly colonises shrub beds.

Prunella grandiflora (© Udo Schmidt)

When to plant selfheal?

Plant selfheal in autumn from September to November or in spring from March to April, avoiding frost and drought periods.

How to plant it?

In the ground

Allow for around 5 buckets per m² to create a beautiful flowering groundcover and cover a good area.

• Dig a hole 3 times wider than the root ball
• Add a few handfuls of sand and gravel to ensure good drainage
• Mix in some compost or potting soil if the ground is too poor
• Place the root ball in the centre of the hole
• Backfill, firm gently with your hands and water thoroughly
• Mulch with a mineral mulch (gravel, pumice, slate, terracotta shards…)

In pots

Prunella thrives in containers (around 30 cm in diameter) and planters with a sufficiently free-draining substrate to avoid waterlogging the roots.

• Place a generous layer of drainage (gravel or clay pebbles) at the base of a pot with drainage holes
• Plant in a mix of potting compost and garden compost
• Mulch and water regularly

Cultivation and care

The selfheal requires little care. In the first year after planting, water regularly, as it needs water to establish well. After that, it can tolerate mild and temporary drought. Mulch the soil with a mineral mulch to reduce watering.

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

Remove spent flowers after flowering.

For larger areas, mow after flowering to thicken the foliage.

Tidy the clump at the end of winter and, if you wish to limit its spread, remove excess stolons.

In pots, ensure the substrate remains moist but not waterlogged: allow the compost to dry out slightly between waterings. Twice during the growing season, enrich the soil with a flowering plant fertiliser to encourage flowering and keep it vigorous.

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

Propagation

Prunella tends to self-layer naturally. During spring or early autumn, you can collect rooted stolons to propagate the plant.

• Use a spade to separate stems connected to the mother plant
• Dig up the leafy stolons
• Replant immediately in moist soil, either in pots or directly in their final position

Pair

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

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

It will edge a bed alongside easy-to-grow perennials such as Nepeta ‘Six Hill Giant’ and Phlox paniculata, as well as ground-covering lady’s mantles like Alchemilla caucasica, which flowers at the same time.

Under trees or bushes, Prunella is a welcome addition among other ground-covering perennials such as Bugleweed (Ajuga ‘Atropurpurea’, ‘Princess Nadia’), Asarum with its heart-shaped foliage, corydalis, Geranium nodosum, and Vinca minor. Deadnettles (Lamium maculatum ‘White Nancy’) or tiarellas and heucherellas will also make excellent companions, with their attractive and colourful foliage.

It forms beautiful cushions at the base of taller plants, particularly at the foot of roses.

It will also create lovely combinations with alpine plants such as alyssum, Dianthus erinaceus, or Geranium cinereum.

In the centre, Prunella x webbiana ‘Rosea’, surrounded by Heucherella ‘Tapestry’, Corydalis ‘Blue Line’, Asarum europaeum, Ajuga reptans, and Heucherella ‘Honey Rose’.

Did you know?

The leaves and flowering tops of Prunella vulgaris possess therapeutic, astringent, haemostatic and vulnerary properties (for healing wounds). This medicinal plant is still used today. It contains, among other things, polysaccharides (prunellin), reputed to boost the immune system. It also has digestive benefits and can be used as an infusion, decoction or mother tincture. The leaves have a slightly bitter taste that can enhance a salad.