Overview
Grandiflora roses are a class of Rosa hybrids reaching 4-6 feet (1.2-1.8 m) tall, sometimes to 8 feet (2.4 m), with a spread of 3-4 feet (0.9-1.2 m), developed by crossing hybrid tea roses with floribundas. The class was created in 1954 to accommodate 'Queen Elizabeth,' which combined the large, well-formed flowers of hybrid teas with the cluster-flowering habit and vigor of floribundas. Flowers are large, 3-4 inches (8-10 cm) across, with 25-35 petals, borne in small clusters of 3-7 on long stems. Flower form ranges from high-centered (hybrid tea style) to cupped. Available in the full range of rose colors. Many are fragrant. Growth habit is tall, upright, and vigorous — the tallest of the bush rose classes. Leaves are alternate, pinnately compound, with 5-7 glossy serrate leaflets. Repeat-blooming from late May through October. The grandiflora classification is not universally recognized; it is primarily an American Rose Society designation. Some international rose societies classify grandifloras as either hybrid teas or floribundas. In the Pacific Northwest, the same disease concerns apply as for other modern roses: black spot, powdery mildew, and rust.
Native Range
Complex hybrid origin. The grandiflora class was established in 1954 for the cultivar 'Queen Elizabeth,' a cross between the hybrid tea 'Charlotte Armstrong' and the floribunda 'Floradora.' Parent species in the hybrid background include Rosa chinensis, Rosa multiflora, Rosa gallica, Rosa foetida, and others.Suggested Uses
Planted at the back of rose beds, mixed borders, or as specimen shrubs where their tall stature provides a backdrop, spaced 3-4 feet (0.9-1.2 m) apart. Long-stemmed flower clusters are valued for cutting. The tall habit can create a hedge or screen effect. Notable cultivars include 'Queen Elizabeth' (pink, the original grandiflora), 'Gold Medal' (yellow), 'Tournament of Roses' (pink), and 'Cherry Parfait' (white edged red).How to Identify
Appearance
Size & Dimensions
Height4' - 8'
Width/Spread3' - 4'
Reaches mature size in approximately 3 years
Bloom Information
Repeat-blooming from late May through October in the Pacific Northwest, with heaviest flushes in June and September. Long-stemmed flower clusters are suitable for cutting. Deadheading promotes continuous rebloom.Detailed Descriptions
Flower Description
Varies: white, pink, red, yellow, orange, bicolorFoliage Description
Glossy dark greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Water deeply 1-2 inches (2.5-5 cm) per week during the growing season, applied at the base. Plant in full sun with at least 6 hours of direct light and good air circulation. Requires fertile, well-drained soil amended with compost. Mulch 2-3 inches (5-8 cm). The tall growth may require staking in exposed sites or after heavy rain. Disease management follows the same protocols as hybrid teas: select disease-resistant cultivars, ensure good air circulation, apply preventive fungicides in wet springs if needed. Fertilize monthly May through August.Pruning
Prune in late winter (February through early March). Remove dead, damaged, and diseased canes. Remove thin, weak growth. Reduce remaining canes by one-third, cutting to an outward-facing bud. Retain 5-7 strong canes. Grandifloras tolerate slightly less severe pruning than hybrid teas due to their naturally tall habit. Deadhead spent flower clusters during the growing season.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
late spring