Funny thing about grandiflora roses, the name suggests large flowers but the flowers aren’t as large as those of hybrid teas. Maybe the English rose growers know something we don’t know; they don’t recognize grandifloras, call them “clustered flowered’ and include them with floribundas. Just to make things more complicated, the first grandiflora rose, a cross between the hybrid tea ‘Charlotte Armstrong’ and the floribunda ‘Floradora’, was named ‘Queen Elizabeth’ in 1954 to honor the ascension of Queen Elizabeth II to the British throne two years earlier. Although raised in the United States, it is widely grown all over the world and does especially well in England where its substantial petals stand up against the rain. In 1978 the World Federation of Rose Societies name ‘Queen Elizabeth’ one of its “World Favorite Roses” and many grandifloras have been chosen as All American Rose Selections (AARS) before and after that date.
As crosses between the hybrid teas and floribundas, grandifloras have characteristics of both. They inherited the flower form and long stems from the hybrid teas, and the increased hardiness and abundance of flowers and continuous blooming from the floribundas. They can produce flowers singly or in clusters, and tend to be considerably taller than either of their parents.
Flower Size: Generally 3 ½ -4” with some being 5” across.
Petal Number: Generally 20-35 but can be up to 50
Form of Flower: High center like hybrid tea
Flower Substance: Variable with some being excellent.
Flower Color: white, pink, red, orange, yellow, and blends
Flowering: Repeats in a series of waves.
Stem: Flowers are borne singly or in clusters; some are excellent cut flowers.
Fragrance; Variable with some being strong and very pleasant.
Size of Bush: 4-8’
Disease Resistance: Variable with some showing excellent disease resistance, others with being susceptiable to both mildew and black spot.
Hardiness: Variable with hardiness to zone 6 being considered “very hardy”.
Heat Tolerance: Variable; better color often in cooler areas.
In addition to ‘Queen Elizabeth’ several outstanding grandifloras are available. ‘Love’, an AARS in 1980, has 4’ red flowers with a silvery reverse, are usually borne on long stems and are excellent for cutting. Good repeat bloomer. Fame! AARS in 1998 has dark pink flowers 5” across that are usually borne singly on long straight stems above healthy foliage on a 5’ bushes. Good yellow grandifloras are a bit harder to come by but ‘Shining Hour’ is an excellent one. AARS in 1991, it has deep yellow fragrant flowers that are usually on a medium height bush. For a white flowered grandiflora on a short bush, ‘White Lightening’ AARS 1981 offers a strong sweet fragrance and flowers appearing in a series of flushes until late autumn. Excellent orange, lavender, and multi-colored grandifloras are also available.