While there are several species that carry the common name of "ice plant," Delosperma cooperi is a warm-weather perennial with intense purplish-pink flowers. The name ice plant derives from tiny hairs on the plant that reflect light in a manner that resembles ice crystals. The foliage is fleshy and succulent-like and morphs into a darker color as fall temperatures drop. In the southern part of its range, the plant can be evergreen. It is often used as a spreading ground cover in sunny areas, where it flowers virtually all summer long. In fact, it can be such a rapid spreader under the right conditions that it's been deemed invasive in some areas. Ice plants are best planted by mid-summer in cooler climates, but in hot climates fall planting is preferred.
|Botanical Name||Delosperma cooperi (formerly Mesembryanthemum cooperi)|
|Common Name||Ice plant, purple ice plant, hardy ice plant, pink carpet|
|Plant Type||Herbaceous perennial|
|Mature Size||3 to 6 inches tall and 12 to 24 inches wide|
|Sun Exposure||Full sun|
|Soil Type||Dry, well-draining|
|Soil pH||6.1 to 7.8|
|Hardiness Zones||6 to 10|
|Native Area||Dry mountains and desert plateaus of Southern Africa|
How to Grow Ice Plants
Ice plants are used in sunny but sheltered desert gardens, in rock gardens, on slopes, or as a ground cover or edging plant. Individual plants often spread around 2 feet, though some instances of plants that are 3 feet or 4 feet across have been reported.
Make sure your planting location has a lot of sun and fast-draining soil; sandy or gravelly soils are best. Space plants 15 to 18 inches apart, as they will quickly spread to fill the empty space. Each spring, prune out any winter-killed stems.
Ice plants prefer full sun, which allows them to flower profusely.
Dry soil with excellent drainage is essential for an ice plant. The plant will suffer under conditions that are constantly moist, and it won't grow at all in dense clay soil. Sandy and gravelly soils are ideal for this plant.
Water your ice plant sparingly, if at all, during the growing season. One watering every two weeks should be sufficient during periods when there is no rainfall. If you have rainfall, you can skip the supplemental watering. Moreover, let your ice plant dry out before winter, so it's not sitting in soil that is too moist. If snow cover is likely in your area, mulch the ice plant with a dry mulch, such as straw, to keep it dry for the winter.
Temperature and Humidity
Although it is sometimes known as the hardy ice plant, this species is quite sensitive to cold temperatures. In the northern range of its growing zones, its hardiness is not guaranteed. So it is sometimes planted as an annual in these areas. Shelter from strong winds and winter mulching is required in any climate that gets regular snow if you want to grow the ice plant as a perennial. Moreover, high humidity can cause ice plants to rot, as they prefer dry conditions.
It can be helpful to add compost or slow-release fertilizer when planting and then a light dose of more compost or fertilizer in the fall. The plants also can do well with no feeding whatsoever. In fact, too much feeding can compromise the plant's ability to survive winter.
Propagating Ice Plants
The ice plant spreads so readily that it is rarely propagated deliberately. But when propagation is desired, the plants can be reproduced simply by taking stem cuttings and rooting them in water or embedding the ends of the cuttings in soil. You'll know roots have formed in the soil when you can gently tug on the plant and feel some resistance.
Common Pests and Diseases
Aphids and mealybugs can be an occasional problem with ice plants. Look for leaf and stem damage and sticky or otherwise abnormal substances on the plants that these bugs leave behind. Treat small infestations by spraying the plants with water to remove the pests. Consider replacing severely infested plants rather than using harsh chemicals that can harm the ecosystem.
Varieties of Ice Plants
A range of closely related Delosperma species is available, offering flowers in yellow, orange, magenta, bicolors, and more. They include:
- Delosperma 'Alan's Apricot' is a hybrid plant that blooms with large pink flowers that gradually fade to apricot.
- Delosperma dyeri 'Red Mountain Flame' begins blooming with bright scarlet-orange flowers in mid-spring for about four weeks.
- Delosperma ashtonii 'Blut' has dark magenta flowers that bloom from late spring into early fall.
- Delosperma 'Fire Spinner' is another hybrid featuring flowers that combine orange and purple. It blooms in late spring.
- Delosperma brunnthaleri (hardy yellow ice plant) has attractive yellow flowers.
- Delosperma floribundum (starburst ice plant) has pink flowers with a white center.
- Delosperma herbeau (hardy white ice plant) is a white-flowered type that offers unusual beauty.