What’s the deal with iceplant? Surely it isn’t native to freeway embankments? Where does it come from? Why plant it along freeways? Is it because succulent plants conserve water and they are suited to dry So. Cal.?
Ice plant (Carpobrotus chilensis) originates in Africa and was introduced to North America to prevent erosion on steep banks. Now it’s a menace to native species. Interestingly, another menace, kudzu, was introduced from Asia for exactly the same reason. http://www.nps.gov/redw/iceplant.htm
We use iceplants in the UK but they cannot stand our winters, or some of our bugs so you only see them in summer when they have been taken from the nurseries.
Except on the very warmest parts of coastal Cornwall and Devon, where they survive all year round; the one we have here is Carpobrotus Edulis, the Hottentot Fig; it has edible fruits.
Ice plant doesn’t need to be watered in Southern California. That’s why it is used so much around schools, freeways, and on slopes.
I never noticed iceplant being very invasive in Southern California. To mention it in the same breath as kudzu seems unfair.