Use a Classic Color Combo-The deep, velvety tones of 'Storm Blue' petunia mix beautifully with the clean white flowers of 'Maverick White' geranium. This easy-to-grow combination creates a bold contrast that will enliven any garden bed or container.
Amaranth is an annual plant. The long strands of reddish-purple flowers on this plant (which is also a grain) are striking, especially since the plant is so tall. What makes it an annual? Learn what distinguishes a perennial from an annual here: http://landscaping.about.com/od/landscapingdictionary/g/annual_plants.htm