In North America, Scotch broom was frequently planted in gardens, and was later used for erosion control along highway cuts and fills. Scotch broom is slightly toxic and unpalatable to livestock, and its seeds are viable for up to ten years, allowing them to regrow many years later, after extermination of the plant.
From Wikipedia:
In North America, Scotch broom was frequently planted in gardens, and was later used for erosion control along highway cuts and fills. Scotch broom is slightly toxic and unpalatable to livestock, and its seeds are viable for up to ten years, allowing them to regrow many years later, after extermination of the plant.