A fast-growing and vigorous groundcover, Creeping Jenny (also known as moneywort) brings mats of low-lying chartreuse color to gardens and containers. Native to Europe but naturalized to Eastern North America, its rounded golden leaves form on trailing stems with small, bright yellow flowers appearing in the summer. A perennial in milder climates, be careful not to plant in areas where spreading would be unwanted—a single plant can grow 2 feet wide and root as it goes. Perfect for softening hard edges, following a pathway or spilling from containers.