Ice plants are a type of succulent belonging to the large and diverse Aizoaceae plant family, often called the ice plant family. They thrive in harsh, dry environments by storing water in thickened, fleshy tissues. The common name “Ice Plant” refers to many species, including popular ground covers found in the genera Delosperma and Lampranthus. These plants exhibit biological adaptations that allow them to survive where non-succulent plants would quickly perish.
What Defines a Succulent
A succulent is defined by its ability to develop thick, fleshy parts specifically for water retention, an adaptation to survive in arid climates or poor soil conditions. This water is stored in specialized large parenchyma cells within the leaves, stems, or sometimes the roots. The Latin root of the term, sucus, translates to “juice” or “sap,” describing the water-rich nature of these tissues.
Succulence is an evolutionary trait, not a taxonomic classification, appearing across more than 60 different plant families. The Aizoaceae family, which includes ice plants, is one of the families where nearly all members are succulents. These plants employ water-saving features, such as a thick, waxy cuticle and Crassulacean Acid Metabolism (CAM). CAM minimizes water loss by opening stomata only at night, allowing the fleshy leaves to endure prolonged periods of drought.
Why Ice Plants Are Named That Way
The common name “Ice Plant” comes from a unique morphological feature that gives the foliage a glistening, frosty appearance. This visual effect is due to specialized structures on the leaves and stems, not cold tolerance. These structures are epidermal bladder cells (EBCs), which are modified, balloon-like trichomes covering the above-ground parts of the plant.
These bladder cells are filled with a water solution and reflect light, causing the surface to sparkle as if covered in tiny ice crystals or dew. Functionally, these cells act as peripheral reservoirs, protecting the plant against short-term water deficit and high salinity stress. The name is purely descriptive of this silvery, crystalline sheen. Ice plants also produce numerous showy, daisy-like flowers that open in the sun.
Growing and Caring for Ice Plants
Ice plants are prized as ground covers for their drought tolerance and minimal maintenance once established. The most important requirement for successful cultivation is ensuring excellent soil drainage. These plants will quickly suffer or die in heavy, dense clay soil that retains too much moisture, which leads to root rot.
Optimal soil is sandy, gravelly, or lean, mimicking the stony, dry conditions of their native South African habitat. Ice plants require full sun exposure, ideally six or more hours per day, to thrive and produce abundant blooms. Insufficient light will result in leggy, stretched stems and diminished flowering.
As succulents, ice plants need minimal water, especially once established. Overwatering is the most common cause of failure, so watering should be sparse, allowing the soil to dry completely between applications. Fertilizer is generally unnecessary, as poor soil is preferred, and excessive nutrients promote foliage growth at the expense of flowers. Hardiness varies by species; for example, Delosperma varieties are reliably perennial down to USDA Zones 5 or 6, while genera like Carpobrotus are less cold-tolerant.