grandifloras

Grandiflora is a class of garden roses that originated from crosses between Hybrid Tea and Floribunda roses. The term was coined in the mid-20th century by rose breeders to describe a group that blended traits from both parent classes. Grandifloras are typically vigorous shrubs or climbing types, with tall canes and an open, spreading habit that suits borders and trellises.

Blooms are the defining trait: flowers are generally large, 2.5 to 5 inches (6–12 cm) across, often semi-double to double, and produced in clusters along the stems. The flowering habit is repeat bloom, with successive waves of blossoms from late spring through autumn. Colors range across the spectrum from white and cream to pink, yellow, and red, with fragrance that varies by cultivar.

Care and cultivation: grandifloras prefer full sun and well-drained, fertile soil. Water deeply at the root zone and mulch to conserve moisture. They benefit from regular feeding during the growing season. Pruning is done in late winter or early spring, removing dead wood and crossing branches and shaping the plant to maintain air circulation. Pests and diseases common to roses, such as aphids, black spot, and powdery mildew, can affect grandifloras, with susceptibility varying by cultivar.

Use: their tall growth and clustered blooms make them popular for garden borders, shrub compositions, and as flowering climbers on arches or trellises. A classic example is 'Queen Elizabeth', a well-known grandiflora that helped establish the class.

See also: rose classifications, including Hybrid Tea and Floribunda.