As a succulent, ice plant (Delosperma cooperi) prefers dry weather and dry soil. It thrives in the gravelly soils typical of rock gardens. From summer into fall, this perennial is covered with an abundance of brilliant purplish pink, daisylike flowers. The foliage forms a dense mat one to two feet wide, so ice plant is a good ground cover as well as an attractive specimen plant. Its name comes from the cylindrical, green leaves with white flakes that remind you of ice.
Common name: Ice plant, purple ice plant
Botanical name: Delosperma cooperi
Plant type: Perennial
Height: 2 to 3 inches tall
Zones: 7 to 10 for the species; may survive in Zone 5 or 6 with winter protection
Sun: Full sun
Soil: Sharply drained
Moisture: Dry, sandy, or rocky
Mulch: None required.
Fertilizer: Apply a slow-release, balanced fertilizer once a month during the growing season.
Pruning: None required.
• Delosperma aberdeenense is a succulent shrub with lavender flowers in summer. It grows 5 inches tall and is a tropical plant hardy in Zones 13 to 15.
• D. nubigerum (yellow ice plant) is a creeping, succulent perennial with dark yellow flowers in summer. It tolerates more humidity than D. cooperi but not as much heat. This attractive ground cover grows 2 inches tall. Zones 5 to 9.
• Plant in a sheltered area of a rock garden or desert garden.
• Pair with other plants that like sharply drained soil, such as alpine poppy (Papaver alpinum, Zones 5 to 8), rock-garden potentilla (Potentilla tridentata, Zones 2 to 8), and ‘Moonshine' yarrow (Achillea ‘Moonshine', Zones 3 to 8).
• Ice plant performs poorly in high humidity and heavy or wet soil. Avoid planting in clay soil.
• There are several plants that have the common name of ice plant. One is Carpobrotus edulis, and it's an invasive plant in California. When purchasing an ice plant, always check the botanical name to make sure you buying the correct plant.
• Mealy bugs and aphids occasionally attack this group of plants.
• Sow seeds at 70ºF.
• Take cuttings in spring or summer.
All in the family
• The Aizoaceae family is a group of succulent herbs or small shrubs, mostly from South Africa or New Zealand. One interesting relative of ice plant is Lithops spp. The common name is living stones or stone plant. It grows among pebbles in semi-desert areas and forms cone-shaped bodies, some of which are the color of rock. It's attractive in containers outdoors but must be brought indoors when temperatures drop below 54ºF. Another relative from the semi-desert areas of South Africa, tiger jaws (Faucaria tigrina) is a succulent with diamond-shaped, toothed leaves with white-dotted undersides. It has yellow flowers and also makes an interesting container plant.
Photo courtesy of Missouri Botanical Garden PlantFinder