All across the Oakland Hills and beyond there are two flourishing plants. Vinca and Ivy. They are both fun plants to hate. They take over, and they harbor snails, slugs and rats who like to make their homes in these beauties. On the other hand, they hold up the steep hillsides preventing erosion, and they look a lot greener than the alternative which is weeds on an unattended hillside. I have trouble resolving my instinct to recreate the native landscape, but at the same time appreciate these types of happy plants. Although I cannot advocate planting new ones, since they've taken over natural landscapes, not just individual residences, which I really don't like, they do have their uses if tamed. Just to be clear, however, the Bay Friendly Coalition has labeled these invasive, and don't like them for another reason - when kept tame and trimmed back, the plant waste contributes to landfills which is part of its mission to avoid doing. My advice is to never plant these, but if you inherited them with your house, keep them from invading the side yard, and slowly replace them with less invasive plants that you don't constantly have to trim back.
Foreground Purple Flowered: Blue Periwinkle
Botanical Name: Vinca major
Behind: English Ivy
Botanical Name: Hedera helix
Located in Upper Rockridge (and all over the hills) district of Oakland, these plants are not irrigated and are in a shady location.