There are 150 or more species of ice plants, with perhaps the best known being the purple ice plant, also called the hardy ice plant, or Delosperma cooperi. These shrubs and mat-forming succulents are native to South Africa. There and in other places around the world they are evergreen; elsewhere they are semi-evergreen or perennial.
The name "ice plant" is believed to have come from the little hairs on the surface of the plant's leaves that reflect and refract light like tiny ice crystals.
Delosperma cooperi grows to about three inches tall, but can spread three or more feet across. It has green triangular leaves that are replaced by daisy-like flowers when it blooms. The leaves sometimes turn red or yellow in the fall. Besides Delosperma cooperi's purple flowers, other species of ice plants have pink, white, or yellow flowers.
Ice plants are useful for xeriscaping, providing good ground cover in hot, dry areas. They are popular for rock gardens.
Certain varieties of ice plant are now considered invasive plants in California, as they have gotten out of control and crowd out native plants in many areas. Delosperma cooperi is not one of the invasive species.
Some varieties of ice plant produce an edible fruit that is made into jam in South Africa.
Ice plants are available in many nurseries year round. They should be planted a foot apart in full sun, in very well-drained, sandy soil with a pH range of 6.0 to 7.5. Add a little fertilizer to the planting hole, and water well until the soil is thoroughly moist.
After that, ice plants are drought-resistant and should not be watered more than occasionally.
Tidy up the plant throughout the year by removing dead stems and spent flowers.
Though they thrive in hot, dry climates, ice plants can be grown in a wide variety of climates, from Zone 5 to Zone 9. As cold weather approaches, reduce watering, as ice plants can sometimes survive freezing or excessive moisture, but not both. Cold damages the succulent leaves the more full of water they are.
Pests and Diseases
Ice plants are insect-resistant, so most pests are not a problem.
Mice and other rodents tend to be attracted to ice plants. Grazing deer are also sometimes drawn to them.