Looking for an indoor-outdoor green friend? The Ice Plant (Carpobrotus edulis) may be the next houseplant to add to your wish list, but take care in keeping it contained to your home and garden.
Ice Plants make attractive angular succulent leaves and have trailing growth along with shimmery yellow or pale pink flowers in spring. The succulent leaves have a “glittery” appearance due to their texture. As potted plants, they need plenty of sun and can be kept outside in the UK unless there is frost. They are frost tender and must be protected or moved inside in winter.
Native to South Africa, the Ice Plant has evolved to thrive in coastal environments with salty spray, steep cliffs, and nutrient-poor sandy soil. Ice Plants can easily outcompete native coastal plant species and become invasive in places like California, USA, the Mediterranean, Australian coasts, and Cornwall, UK. When Ice Plants take over an area, they make the soil more acidic - which is favourable to Ice Plants while making it more difficult for other plants to grow.
How did this frost tender plant become invasive in the UK though? Ice Plants have taken over specific areas of Cornwall, where the cliff and dune environments rarely have frost due to the warm Gulf Stream ocean current. They are escapees from gardens where Ice Plants are used as ground cover, and in the mid 20th century it was introduced to slow dune erosion. Some areas, like the scenic Lizard Point in Cornwall, are carpeted in Ice Plants and many visitors assume they are a native species. Although the climate is not warm enough for their fruits to ripen, the plant spreads prodigiously via fragmentation (new plants growing from broken off pieces). Therefore, there is probably low genetic diversity among the Ice Plant populations in Cornwall, which may make them more vulnerable to pests and diseases in the long run.
The Ice Plant can be a “nice plant” as long as you keep it strictly in captivity!