Iceplant (Carpobrotus edulis) is a coastal succulent shrub native to the coast of South Africa, where the climate is similar to that of coastal California. Iceplant was introduced to California in the early 1900s as an erosion stabilization tool used on railroad tracks, and later used by Caltrans on roadsides. It has been used as an ornamental for many years, and is still sold in nurseries. Unfortunately, iceplant spreads easily, and has become invasive in coastal California from north of Humboldt County to as far south as Baja California. When it establishes in a location, it forms a large, thick mat that chokes out all other native plants and alters the soil composition of the environment. Because it is a coastal invader, it competes with many endangered, threatened, and rare plants.
Iceplant is shallowly rooted, so it is possible to control it manually, and iceplant removal provides a good volunteer day for student groups. Unfortunately, it is so widespread that it is only realistic to try to control small infestations at once. It is important to follow iceplant removal with rehabilitation of the area because it is easy for iceplant to re-establish in bare soil. Although iceplant can be attractive, it is important not to plant it in areas where it may become invasive. There are many other coastal species native to California you could choose to use instead, and below is one example.
Purple sage (Salvia leucophylla) is a California native evergreen shrub that will grow 3-6 feet and produces light purple flowers from May to July. It is a coastal species and once it is established it requires no watering and is good for erosion control. It attracts pollinators such as native bees and butterflies, and is a great addition to the garden.