Lampranthus is one of several genera of plants in the Aizozaceae family that are known collectively as ice plants. All are native to Africa and all are succulents with distinctive daisy-like flowers. One of the largest groups is the Lampranthus genus, which includes more than 150 species of flowering plants with thin petals in vivid shades of color. The leaves of plants in this genus are usually short, cylindrical, and blue-green, with tiny transparent flakes that give an icy appearance Some Lampranthus ice plants are low-growing spreaders while others become bushy subshrubs. Many ice plants put on their best show in the spring with sporadic repeat blooming throughout the season, and a few species bloom all summer with the right care and conditions.
|Botanical Name||Lampranthus spp.|
|Common Name||Ice plant|
|Plant Type||Succulent perennial, often grown as an annual|
|Mature Size||Up to 2 feet tall|
|Sun Exposure||Full sun|
|Soil Type||Sandy, well-draining soil|
|Bloom Time||Spring, summer|
|Flower Color||Red, pink, orange, yellow, purple|
|Hardiness Zones||8 to 11 (USDA)|
|Native Area||Southern Africa|
How to Grow Ice Plants
Size and shape vary among the species within the Lampranthus genus, but most of the commonly grown ice plant varieties reach up to 2 feet tall and have a spreading habit. Ice plants thrive in sunlight and poor soil, and they make a wonderful alpine or rock garden plant. They also can be tucked into stone walls. Their spreading habit means they quickly fill a container and spill over, so they are nice in hanging baskets and free-standing pots.
You can grow ice plants by division, cuttings, and seeds. If you’re dividing established plants, do so in the spring. Cuttings can be taken and rooted at any point during the growing season, though they are best planted outdoors as early in the season as possible. If you’re growing by seeds, simply scatter them over the soil in the spring, but don’t cover them, as they need light to germinate.
All varieties of ice plants grow and bloom best in full sun. Their flowers tend to open to their fullest extent under sunny conditions and plenty of sunshine helps prevent the plant from becoming leggy.
The key to growing ice plants is to provide sandy (or gravelly), well-draining soil with a neutral soil pH. This plant is fine in soil that's low on nutrients, but avoid clay soil and any location where the plant will sit in water. Ice plants will rot and die if they're left in wet soil for a prolonged period.
As succulents, established ice plants are extremely tolerant of drought. However, they do prefer regular watering roughly once a week, especially during the hottest part of summer. If you're growing your ice plants in a container, you'll likely have to water them slightly more often than those planted in the ground. Allow the soil to dry out between watering in the winter when ice plants are somewhat dormant. Water seedlings regularly to keep the soil moist but not wet.
Temperature and Humidity
Despite their name, ice plants don't tolerate icy, cold weather. Hardiness depends on the species and variety, but most plants from this genus prefer only warm climates. While some species can tolerate a light frost, gardeners in cold climates do best growing them as annuals or houseplants. Moreover, high humidity and damp conditions can cause ice plants to rot. They thrive in dry climates.
Fertilizer usually isn't necessary for in-ground ice plants, as they grow well in poor soil. If blooming is sparse, feeding might be a solution. Likewise, plants grown in containers deplete their nutrients more rapidly and can benefit from a balanced fertilizer applied following label instructions.
Propagating Ice Plants
Taking cuttings is the fastest method for propagating ice plants. Make cuttings while the plant is actively growing from the spring to early fall. Cut shoots about 3 to 6 inches long, and remove all but the top set of leaves.
Allow your succulent cuttings to dry and form calluses by leaving them out in the air for several hours or overnight. Then, root them in a well-draining container filled with a succulent potting mix. Keep the soil evenly moist until the cuttings root. You can tell when roots have formed by gently tugging on the cuttings. If they offer resistance, they're ready to be repotted into a bigger container or transplanted into the ground come springtime.
Common Pests and Diseases
Weather (damp conditions, cold spells, etc.) often is the biggest hurdle when growing ice plants. Soil that is too moist can grow fungi that will kill your plant. Mealy bug and scale occasionally infest ice plants, though the proper growing conditions can typically keep a plant healthy enough to ward off both pests and diseases.
Varieties of Ice Plants
Some popular varieties of ice plants from this genus include:
- Orange ice plant (Lampranthus aurantiacus): Spring-blooming, upright plant with bright orange petals around a yellow center
- Purple Vygie (Lampranthus haworthii): Covered with pink or purple flowers in the spring, along with blue-green leaves
- Redflush ice plant (Lampranthus coccineus): Features bright red flowers throughout the season and is somewhat frost tolerant
- Trailing Ice Plant (Lampranthus spectabilis): A low-growing, spreading plant with white or purple-pink blooms
Compared With Delosperma Species
Another popular genus of landscape plants in the Aizozaceae family is Delosperma, which includes more than 100 species, including the popular D. cooperi. The Delosperma species are also known as ice plants; they look quite similar to the Lampthanthus species and are used in a similar fashion in the landscape. They are distinguished only by differences in the seed structure and less diversity of color—Delosperma ice plants generally have red-purple blooms. You can grow them in much the same way as the Lampthanthus ice plants.