A favorite among generations of gardeners, gladiolus add drama and color to gardens and cut-floral displays. Gladiolus often grow 3-4 ft. tall and are planted as foundation plantings, focal points, in cutting gardens and in back borders. Available in an array of color, including deep red, pink, white, yellow, deep magenta, green, orange and dark purple, gladiolus look impressive when they are planted in groups. These tender perennials are planted in the spring and bloom in summer to fall. They perform best when planted in well-drained soil and in full sun. When selecting gladiolus bulbs to buy, take into account their growing requirements, flower color and mature height and spread.