5. Periwinkle (Vinca minor)
A common evergreen ground cover, periwinkle may look nice in your garden, but it can quickly spread rapidly into natural areas. Once it spreads, it poses a threat to native biodiversity. Its thick growth smothers native ground vegetation. Both big-leaf periwinkle and small-leaf periwinkle are considered invasive, but they are often recommended by garden centres as a fix for any problem spots in the garden because they grow so prolifically. Native to the Mediterranean, periwinkle was introduced to North American as an ornamental ground cover and medical herb.