Ground-covering plants solve a lot of garden challenges and give gardens a finished look. Groundcovers are usually low-growing plants that are easy to grow. They're ideal for covering bare spots, filling in challenging areas such as slopes and around trees, and choking out weeds. Some ground covers, such as sedums, hostas and ornamental grasses, are grown primarily for their foliage, while others, like lilies, daylilies and phlox, brighten areas with their flowers. When buying ground-covering plants for sale online, make sure the plants will grow in your hardiness zone. Next, consider their light requirements, soil requirements, water needs, mature height and spread, flowering time and your personal preference.