There are many genera and species that carry the common name of "ice plant." Two of the most popular genera are Lampranthus and Delosperma cooperi. These plants are warm-weather perennials with brightly colored flowers, including pink, purple, red, yellow, and orange. 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.
Ice plants can take the form of everything from a spreading ground cover to a bushy subshrub, depending on the type. They typically bloom best in spring and often bloom again later in the growing season. In sunny areas, some types flower virtually all summer long. In fact, ice plant can be such a rapid spreader under the right conditions that it has 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. In warm regions, many types of ice plant are evergreen.
|Botanical Name||Delosperma spp ., Lampranthus spp .|
|Common Name||Ice plant|
|Plant Type||Herbaceous perennial|
|Mature Size||3 to 24 inches tall and 12 to 24 inches wide, depending on variety|
|Sun Exposure||Full sun|
|Soil Type||Dry, sandy, well-draining|
|Soil pH||6.1 to 7.8|
|Bloom Time||Spring, Summer|
|Flower Color||Pink, red, purple, yellow, orange|
|Hardiness Zones||6 to 11, depending on variety|
|Native Area||Southern Africa|
How to Grow Ice Plants
Ice plants are used in sunny but sheltered desert gardens, in rock gardens, on slopes, or as ground cover or edging plants. Individual plants often spread around 2 feet, though some instances of plants that are 3 feet or 4 feet across have been reported. They also work well as container plants that easily fill the top and eventually spill over the sides of the container.
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. Sun-starved plants tend to get leggy.
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. The soil does not need to be rich in nutrients.
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, although a weekly watering may be needed during hot weather. 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
All types of ice plant, including the "hardy" varieties, are sensitive to cold temperatures. Be sure to check the hardiness range for any new ice plant you'd like to grow as a perennial. If you live in a snowy climate, winter mulching may be recommended. At the other end of the spectrum, ice plant doesn't like high humidity, which can lead to rot. It grows best in dry climates.
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. Container-grown ice plants may need a balanced fertilizer from time to time, as the soil in pots becomes depleted more quickly than garden soil.
Varieties of Ice Plants
- Delosperma brunnthaleri—Hardy yellow ice plant: A hardy ground cover that grows about 2 inches tall and 2 feet wide; yellow flowers; suitable for zones 4 to 9
- Delosperma floribundum 'Starburst': A mat-forming cultivar with pink flowers with white centers; suitable for zones 6 to 8.
- Delosperma cooperi—Cooper's hardy ice plant: Magenta flowers and a height of 1 to 2 inches; suitable for zones 5 to 9
- Lampranthus aurantiacus—Orange ice plant: Bright orange flowers and an upright habit reaching 14 inches in height; suitable for zones 9 to 11
- Lampranthus haworthii—Purple vygie: Blue-green foliage and pink or purple flowers; suitable for zones 9 to 11
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.
Cuttings have the best chance at survival when they are planted in the spring so they have a long growing season for getting established.
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 that these bugs leave behind on the plants. 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.