<em>Delosperma</em>, perennial purslane: plant and grow

Description and botany

Le Delosperma, ice plant or perennial ficoid is a succulent plant belonging to family Aizoaceae, native to rocky cliffs and the rugged plains of South Africa, East Africa and Madagascar. The genus includes more than 150 species of bushes and mat-forming perennials, but fewer than ten are commonly offered in cultivation. Delosperma cooperi, or Cooper’s ice plant, is the best-known and most widely grown species.

The Delosperma hybrids of the new ‘Wheels of Wonder’ series are frequently seen, notable for their flowers twice the size of the species, available in a range of six brilliant, radiant colours. Less often encountered are Delosperma crassuloides with white flowers and Delosperma echinatum, two tender species reserved for Mediterranean climates.

Delosperma forms a small low tuft with an erect or prostrate, even trailing habit, not exceeding 10 to 15 cm in height. Its very brittle stems root and branch easily on contact with the soil, spreading each year and can quickly carpet an area up to 1 m wide if conditions suit. It develops into a very dense groundcover and can remain in place for many years.

Its succulent foliage, compact on the creeping stems, is evergreen. Sessile, very fleshy and pointed, the leaves measure 0.5 to 5 cm long, are triangular to cylindrical and appear in opposite pairs. Their epidermis is verrucate, covered with tiny papillae that protect it from the blazing sun. The succulent leaves store water and serve as a reserve for the plant. They come in every shade of green, from pale to glaucous blue-green; some have white highlights, hence the English nickname “Ice Plant”.

Delosperma cooperi – botanical illustration

Delosperma produces an abundant, bright and highly coloured flowering display from June until the frosts. The star-shaped flowers, 0.5 to 5 cm in diameter, occur in solitary heads or gathered in fairly loose cymes at the tips of the stems, studding the foliage so spectacularly that they can almost entirely cover it, especially in the ‘Wheels of Wonder’ range, which bears flowers twice the size of the species.

The corollas, daisy-like in appearance, are formed of numerous fine, shiny ligules radiating around a golden-yellow, white or pink centre that contains a multitude of stamens. Pure golden yellow, mauve, lilac, crimson red, white or bright orange, the colours are so vivid and brilliant they look painted and are noticeable from afar. Some are bi-coloured.

Several flower colours: Delosperma Wheels of Wonder Hot Pink, Delosperma Wheels of Wonder White, Delosperma Wheels of Wonder Fire, Delosperma Wheels of Wonder Golden

They have the habit of opening at sunrise and closing in the evening at dusk. Generous, they continue to renew until early autumn, attracting butterflies to your garden.

, the ice plant is best reserved for Mediterranean climates, coastal gardens and mild regions where severe frosts are uncommon. In cold climates and regions with harsh, wet winters, it is preferable to grow it in tubs or pots and bring it into a conservatory over winter if temperatures fall below -8 to -10°C.

Fleshy foliage of Delosperma (photo Charlie Gaddy-Flickr)

To thrive, it needs a very sunny exposure in very well-drained soil, even dry and rocky, and tolerates sandy seaside soils. From its origins it has retained very good drought resistance.

Plant it on the edge of a dry border, in a rockery, in pots, in window boxes or on a well-exposed bank.

Main species and varieties

Most popular

Our favourites

Delosperma cooperi

With its many mauve flowers it is the best-known species and the most used as groundcover. It is ideal for covering low walls and filling rockeries or in hanging baskets.

• Flowering time July to October
• Height at maturity 10 cm

See the product sheet

Delosperma Wheels of Wonder Golden - Ice Plant

A variety from Japan, selected at the Innovert 2014 competition at Salon du Végétal. It establishes easily between stones, path slabs or on a dry bank.

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

See the product sheet

Delosperma Wheels of Wonder Hot Pink - Ice Plant

A new delosperma hybrid notable for its large flowers in striking colours. Plant above low walls, in rockeries, or in a pot to adorn a terrace.

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

See the product sheet

Delosperma Wheels of Wonder Orange - Ice Plant

It is one of six varieties in the ‘Wheels of Wonder’ series, notable for its vigorous, floriferous plants with larger, brightly coloured flowers. A rockery plant par excellence but it will also thrive in a container.

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

See the product sheet

Ice Plant Stardust Seeds - Delosperma floribundum

We like its long flowering of blue and white star-shaped flowers. Use in rockeries, pots or well-exposed window boxes.

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

See the product sheet

Planting

Where to plant Delosperma or perennial purslane

It is a plant of warm, dry climate. The Delosperma or perennial purslane has fairly moderate hardiness (it tolerates frosts down to -8 to -10 °C in very well-drained soil), so planting is best reserved for regions where winters are not too severe.

Some species that are really too tender (Delosperma echinatum) tolerate temperatures below 0 °C poorly and will only be grown in gardens in southern France. In cold and especially damp climate, it is preferable to grow it in a pot to shelter in winter under a conservatory and bring out in fine weather.

Resistant to drought, wind or sea spray, it is a perennial well suited to Mediterranean climate and coastal gardens.

It requires full sun and warmth to flower well in very well-drained, rather poor, dry, even stony soil: it is the dry rockery plant par excellence that copes perfectly with poor soils and grows provided it finds a little substrate. It thrives in sandy soils. In contrast, heavy soils saturated with water, such as freezing rains in winter, are fatal.

It is essential as groundcover in seaside and dry gardens, in arid rockeries, between stones, on paving slabs, on a bank, atop a low wall or even in a bowl, a hanging basket or a pot to bring indoors for winter if necessary.

When to plant Delosperma or perennial purslane

Plant the perennial purslane in spring, from February to April so it has time to establish roots before winter, or from August to October outside periods of frost or intense drought.

How to plant the Delospermas or perennial purslanes

In open ground

Allow about 5 to 6 young plants per square metre, spaced 30 cm apart for a beautiful flowering tapetum with succulent leaves.

In heavy soil, add coarse sand or gravel to the bottom of the hole to improve drainage.

• Soak the rootball before planting
• Dig a hole 2 to 3 times wider than the bucket
• Remove from bucket and position the rootball
• Backfill, adding a little river sand to garden soil
• Firm lightly
• Water until established

In a pot

Substrate must be light and very free-draining to avoid stagnant moisture at the roots. Place the Delosperma in full sun in a pot at least 30 cm in diameter.

• Lay a good draining layer (gravel or clay pebbles)
• Plant in a mix of potting compost, garden soil and gravel
• Shelter it from frost and winter rains by bringing it into a greenhouse
• Water regularly without excess

→ Learn more about growing Delosperma in a pot here

When and how to sow perennial purslane seeds

Sowing of Delosperma or ice plant seeds is done in seed tray in March or outdoors in April–May.

In seed tray

• At 18–21 °C, sow thinly by scattering in seed tray on moist potting compost
• Do not cover seeds; place in light and keep moist until germination, which takes 10–21 days
• As soon as seedlings are sturdy enough, prick out into 7 cm buckets
• Plant in May in open ground, spacing plants about 25 cm apart once risk of frost has passed, or in pots or window boxes

In open ground

• Sow perennial ice plant seeds thinly by scattering on light soil mixed with coarse sand
• Cover with a fine layer of potting compost
• Firm down
• Water
• Thin seedlings to leave 25 cm between plants

Maintenance, pruning and care of Delosperma

Very undemanding, perennial ice plant grows unaided without maintenance, withstanding drought provided conditions suit it: a sunny spot in well-draining soil with no standing water at its base. Once established, Delosperma is disease-resistant as it only suffers from excess moisture.

It is a succulent plant capable of storing large amounts of water.

Water only during first year after planting; once well established, it will live on rainwater, perfect for a garden without watering!

Remove faded flowers to encourage renewed flowering.

In autumn, prevent plant from being covered by dead leaves that could cause its foliage, very sensitive to excess water, to rot.

Every 2 to 3 years, in spring or autumn, divide the stump to regenerate the plant.

In a pot, water only once a week, keep dry in winter. Optionally apply a liquid fertiliser in spring to encourage abundant flowering.

Delosperma Wheels of Wonder Hot Pink

When and how to prune delosperma

The perennial ice plant is a groundcover that can sometimes be invasive. No pruning is really necessary; the only task might be to limit its spread by removing layering roots in early spring: cut them with pruning shears.

Remove any parts damaged by rain.

Propagation

If sowing is possible, simplest option is to take stem cuttings in summer. Division is also possible in autumn but more delicate because of fragility of Delosperma stems.

Propagation by cuttings of Delosperma

• Between July and September, take a stem with adventive roots
• Leave it to dry for a day or two
• Plant in small pots filled half with garden soil, sand and a little compost
• Cover with sand
• Firm down
• Water cuttings regularly
• Overwinter them frost-free under a cold frame
• Plant out into open ground the following spring when soil is well warmed and all risk of frost has passed

Uses and companion plants in the garden

Perennial ice plant is indispensable in rockeries and dry holiday gardens without watering, where it forms a colourful flowering tapetum.

Delosperma ‘Kelaidis’ in dry garden (photo cultivar413-Flickr)

Planted en masse, it provides contrast with its vibrant hues, in monochrome or variegated versions.

Easy to combine with plants sharing same needs: sun and dry soil.

On the edge of a sun-loving border, it is perfect accompanied by a few achilleas, at the feet of valerians, poppies or rockroses. At the edge of a mineral bed, it will add a small touch of colour, slipped among grasses.

An idea for a combination in a sunny, dry situation: Delosperma cooperi, Thymus serpyllum ‘Minimus’ and Artemisia canescens (photo Peganum)

In a dry rockery, it thrives alongside other perennial ground-covering and undemanding plants ideal for covering large areas on poor, dry ground such as lamb’s ears, Sedums, Dianthus, wall campanulas and Stachys.

→ Discover other ideas for combinations with Delosperma in our advice sheet !