Foxtail ferns (Asparagus densiflorus), also known as asparagus ferns, are semi-evergreen perennials with plumes of emerald green foliage. They have a clumping habit that reaches 2-3 feet high by 3 feet wide. They can be planted indoors and outdoors, preferring part shade outdoors and full sunny spots indoors. Gardeners commonly associate it with ferns because of its clumping habit and soft, green foliage, but the asparagus fern is a member of the lily family and is related to the asparagus vegetable. This plant is toxic to humans and pets. The Foxtail Fern produces produce fragrant tiny white flowers in the spring and red berries follow behind them. There is no guarantee that the flowers or red berries will appear yearly. Be careful, the red berries are toxic to humans if consumed, but birds will enjoy them. Foxtail Ferns grow best in part shade, allowing the perennial plants to grow lush habits and emerald green foliage. If planted in part sun, the foliage is lighter green. A fully mature plant averages 2-3 feet in height and 3 feet in width.