Ice Plants (Delosperma)

How to choose an ice plant

The species, Ice Plant Delosperma cooperi, is the familiar hardy ice plant with bright magenta purple flowers. It grows about 10 to 15 centimetres high and spreads to 60 centimetres or so. The Suntropics selections offer other colours on the same low, spreading habit: Ice Plant Suntropics Hot Pink, Suntropics Red Ice Plant, Suntropics Yellow Ice Plant and Suntropics Purple Ice Plant are each named for their flower colour. Planting two or three colours together gives a brighter result than one alone, and they knit into a single carpet.

Ice plants are relatives of pigface, with the same fleshy leaves and shining petals, but they are finer in leaf, lower and neater. If you need something larger and faster for a broad sandy bank, look at our pigface as well.

Where ice plants grow

Full sun is essential, because the flowers stay shut in shade. Ice plants suit warm temperate, cool temperate, Mediterranean and arid climates, and they handle frost well when the soil is dry. They also grow in the subtropics in a raised, open position, though long periods of summer rain and humidity can rot the centre of the mat. They are not suited to the wet tropics.

They tolerate coastal exposure, poor soil and reflected heat from paving and walls. That makes them useful on a hot verge, along the top of a retaining wall where they can trail over the edge, in gravel gardens and between rocks. You will find companions for them among our rockery plants and other drought tolerant plants.

Planting and spacing

Plant in spring or autumn. Sharp drainage is the one firm requirement: sandy or gravelly soil is ideal, and in clay you should build the bed up and mix in coarse sand or fine gravel. Space plants 30 to 40 centimetres apart for a continuous cover within a season or two. In pots and bowls use a cactus and succulent mix. Mulch with gravel in preference to bark, which holds moisture against the stems.

Care basics

Water regularly for the first few weeks, then only in long dry spells. Established plants are drought hardy, and too much water does more harm than too little. Keep them fairly dry through winter in cold districts, as cold combined with wet soil is what kills them.

Feeding is rarely needed. A light dose of a low phosphorus slow release fertiliser in early spring is plenty, and rich soil produces leaves at the expense of flowers. Trim lightly after the main flush to tidy spent flowers and keep the mat dense. If the middle of an old plant thins out, cut it back in spring or replace it with rooted pieces from the edge. Stems root where they touch the soil, so new plants are easy to lift.

Common questions

Why are my ice plant flowers closed?

The flowers open only in bright sun. They close in the evening, on overcast days and in shade.

Are ice plants the same as pigface?

No. They are related and look similar, but Delosperma is a smaller, finer plant than pigface (Carpobrotus), with smaller leaves and a lower mat.

Do ice plants tolerate frost?

Yes, provided the soil drains freely. Frost on dry ground does little damage, while frost on waterlogged ground can kill them.

Can I walk on ice plants?

No. The fleshy stems crush easily, so plant them where they will not be trodden on.