Hardy ice plant

Hardy ice plant: how do you recognise it?

Habit

Low, creeping mat 5–10 cm high that grows to about 50 cm wide; the stems root where they touch the soil.

Leaves

Fleshy and cylindrical, 2–5 cm long, fresh green and covered in tiny glistening bladder cells.

Flower

Star-shaped flowers 4–5 cm across with countless narrow, shiny petals, vivid pink to purple-pink with a white centre.

Flowering time

June to September; the flowers open in the sun and close in the evening.

Roots

Fine and shallow; they cannot stand wet soil.

Flowering: June–September · Plants: April–June · Pruning: April

Why grow it?

• Four months of flowers, in a colour you can see from afar, from June to September.
• Grows in the hottest, driest spots, where other plants scorch.
• Evergreen: the fleshy leaves stay on the plant in winter.
• Bees love to visit the flowers on sunny days.
• Little work: no feeding, hardly any water and almost no pruning.

Hardy ice plant: where does it grow best?

• Full sun, ideally the hottest spot in the garden: south-facing, against stones or in gravel.
• Poor, free-draining sandy soil or loam, acid to chalky; mix plenty of gravel into heavy soil.
• Dry: it tolerates long droughts but not wet soil, especially in winter.
• Plant 30–40 cm apart for a closed mat. A slope, a rock garden or a wall is ideal.

Light

Sun

Soil type

Sand or loam

Acidity

Not fussy

Moisture

Dry

Size

0.1 m tall, 0.5 m wide

Hardiness

Hardy (to -20 °C)

Goes well with

• Houseleek: The same dry, sunny spot; rosettes beside the flowering mat.
• Stonecrop: Yellow or white starry flowers and a similar way of growing.
• Blue fescue: Blue-grey tufts beside the vivid pink flowers.
• Thyme: Scented leaves and small flowers in a gravel garden.

Hardy ice plant: when and how to plant it?

Plant in April–June.

1. Plant in April–June, after the hardest frosts, so it is well rooted before winter.
2. Loosen the soil and mix in plenty of gravel or coarse sand. No compost or fertiliser.
3. Set the plant at the same depth as in the pot, or slightly higher, so the base of the stems stays dry.
4. Space plants 30–40 cm apart; allow 6–10 plants per m².
5. Water after planting and after that only in long dry spells.
6. Scatter a layer of gravel around the base: it keeps the leaves dry and reflects the heat.

Care

Water

Once established, almost never; only in a pot or trough during weeks of drought. Better too dry than too wet.

Feeding

Not needed: in rich soil it becomes floppy and flowers less.

Weeding

For the first few years keep the mat free of weeds and grass, which root easily between the stems.

Tidying

In autumn, remove fallen leaves from the mat so it does not rot.

Renewing

After a few years the centre sometimes goes bare: fill the gap with fresh cuttings.

Tip: Spread a 3–5 cm layer of gravel around and under the plant: the leaves stay dry, the roots do not rot and the warmth of the stones gives better flowering.

Hardy ice plant: when to prune it?

Pruning months: April.

When: Hardly any pruning is needed. In April, cut out dead or frosted pieces once you can see which parts are shooting again.

How:

• Cut brown, shrivelled or rotten stems back to healthy green growth.
• Trim stems that spread too far over paths or other plants; you can use the pieces as cuttings straight away.
• There is no need to deadhead: the spent flowers dry up by themselves.

Caution: Do not prune in autumn: wounds in the fleshy stems rot easily in a wet winter.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

From April to August: cut 5–8 cm pieces of stem, let them dry for a day and push them into sandy soil. They root within a few weeks, even directly in the garden.

Division

In April–May: dig a rooted piece from the edge of the mat and replant it at once in a dry spot.

Hardy ice plant: how does it get through the winter?

Hardy to −20 °C.

• Hardy to about −20 °C, but only in dry, free-draining soil: cold and wet together are fatal.
• A slope, a wall or a thick layer of gravel keeps the roots dry through a wet Belgian winter.
• Do not cover it with leaves or mulch: they hold moisture and make it rot.
• In a pot or trough: move it under an overhang in winter, out of the rain, and do not water.

Diseases and pests

• Rot: Stems turn soft, brown and glassy, usually after a wet winter. Cut out affected parts, improve drainage with gravel and keep a few cuttings in reserve.
• Few flowers: Too much shade or soil that is too rich. Move it into full sun and do not feed.
• Bare patches: The centre of an old mat dies off. Fill in with cuttings and scatter some gravel.
• Weeds: Grass and weeds easily grow through the open mat. Hand-weed regularly, especially in the first two years.
• Slugs: They can eat young plants in a damp spring. Pick them off in the evening; they rarely come to a dry, gravelly spot.

Through the year

• March: Remove fallen leaves from the mat. Start weeding.
• April: Cut out dead pieces. Plant. Take cuttings and divide.
• May: Plant. Weed.
• June: Flowering begins. Plant. Take cuttings.
• July: Full flower. Water only pots during long dry spells.
• August: Flowering. Take cuttings.
• September: Last flowers.
• October: Remove fallen leaves from the mat.
• November: Move pots under an overhang.
• December: Rest. Keep dry.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The leaves are covered in tiny translucent bladder cells that glitter in the light like ice crystals; that is where the name ice plant comes from.
• The flowers only open in sunshine and close in the evening and in cloudy weather.
• As in many of its relatives, the seed capsules only open when they get wet: raindrops splash the seeds away.