Introduction & History

Few climbing roses make as bold a first impression as Altissimo. Introduced in 1966 by the celebrated French hybridizer Georges Delbard, this large-flowered climber broke convention by presenting blooms of striking simplicity rather than the stuffed petal counts fashionable at the time. Each flower opens to reveal just five to seven velvety, blood-red petals arranged around a magnificent boss of golden stamens, creating a display that recalls the elegance of wild roses scaled up to dramatic proportions. Altissimo has become one of the most widely planted red climbers in the world, earning accolades for its tireless repeat-blooming habit, exceptional disease resistance, and the almost luminous quality of its scarlet flowers against dark, leathery foliage. Whether trained on a pillar, along a fence, or up a sunny wall, it delivers a season-long performance that few rivals can match.

Breeding History

Altissimo was bred by Georges Delbard in France and introduced commercially in 1966. Its parentage is listed as Tenor crossed with an unnamed seedling. Delbard sought to create a climber that combined the visual impact of single-petaled species roses with the repeat-flowering vigor of modern hybrids. The name, drawn from the Italian musical term meaning very high, references both its climbing habit and the soaring ambition of the breeding program. Altissimo received widespread recognition, including awards from the Royal National Rose Society and strong ratings from the American Rose Society. It remains one of the top-rated single-flowered climbing roses in international trials.

Flower Form & Fragrance

Altissimo produces single to semi-double blooms with five to seven broad, velvety petals in a vivid, non-fading blood red. Each flower measures 10-12 cm across and opens flat to reveal a spectacular crown of bright golden-yellow stamens. Blooms appear singly or in small clusters of two to three throughout the season, from early summer until frost. The fragrance is mild but noticeable, carrying a light, fresh scent with subtle spicy undertones. The contrast between the saturated red petals and the golden stamens is one of the most photogenic combinations in the rose world.

Garden Design & Uses

Altissimo excels on pillars, obelisks, and short walls where its vivid red flowers can be displayed at eye level. It pairs beautifully with silver-leaved plants like artemisia and lavender, or with blue-flowered companions such as clematis and nepeta. The single blooms produce ornamental hips in autumn if spent flowers are left, adding seasonal interest. Use it as a focal point against a light-colored wall or interplant with a white-flowered climber like Climbing Iceberg for dramatic contrast. Its moderate size makes it suitable for smaller gardens where larger ramblers would overwhelm.

Growth Habit & Hardiness

Altissimo grows to 250-350 cm tall with a spread of 150-200 cm. It produces stiff, upright canes that are relatively easy to train on structures. Foliage is large, dark green, semi-glossy, and leathery in texture, providing an excellent backdrop for the red blooms. Thorn density is moderate with medium-sized, curved prickles along the canes. Growth is vigorous but controlled, making it a manageable climber that does not become unruly. New basal shoots emerge readily, ensuring the plant rejuvenates well after pruning.

Climate & Hardiness

Altissimo is hardy in USDA zones 5b through 10a. It tolerates heat well and continues blooming strongly through summer in warm climates. Cold hardiness is excellent for a climbing rose, surviving winters down to -26 degrees Celsius with minimal dieback when properly established. It shows good rain tolerance, with the single-petaled blooms shedding water rather than balling. In humid climates, its outstanding disease resistance keeps foliage clean without intensive spraying.

Seasonal Care Calendar

Planting & Container Growing

Plant Altissimo in well-drained, fertile soil with a pH of 6.0-6.8. Space plants 180-240 cm apart when planting multiples along a fence. Set the bud union 5-8 cm below the soil surface in cold climates, at soil level in mild areas. Prepare a planting hole at least 45 cm deep and wide, incorporating generous amounts of compost and well-rotted manure. Ensure the planting site receives a minimum of six hours of direct sunlight daily for optimal flowering.

Container Growing

Altissimo can be grown in containers with a minimum size of 50-60 liters. Use a loam-based compost mixed with perlite for drainage. Water daily in summer as climbing roses in pots dry out quickly. Provide a sturdy obelisk or trellis in the container for support. Feed fortnightly with a balanced liquid rose fertilizer during the growing season. Container feasibility is rated moderate: it will bloom well but never reach its full potential size. Repot every two to three years, refreshing the compost.

Seasonal Care & Pruning

In spring, remove dead or damaged wood and shorten lateral shoots to two to three buds. Tie in new growth and apply a slow-release rose fertilizer. Through summer, deadhead regularly to encourage repeat blooming, water deeply during dry spells, and apply a second feed in midsummer. In autumn, allow the last flush of blooms to set hips for winter interest. Reduce watering gradually. In winter, check ties and supports for damage, mulch the base with 8-10 cm of organic material, and avoid hard pruning until late winter or early spring.

Common Mistakes to Avoid

The top five mistakes with Altissimo are: 1) Pruning too hard and removing the structural canes that produce lateral flowering shoots. 2) Planting against a hot south-facing wall without adequate watering, leading to stress. 3) Neglecting to train canes horizontally, which reduces the number of flowering laterals. 4) Deadheading all spent blooms and missing the attractive autumn hip display. 5) Over-fertilizing with high-nitrogen feeds, which promotes lush foliage at the expense of blooms.

Propagation

Altissimo can be propagated by hardwood cuttings taken in late autumn, by semi-ripe cuttings in summer, or by budding onto Rosa laxa or Dr. Huey rootstock. Hardwood cuttings of 20-25 cm lengths root reasonably well in a sheltered nursery bed. Budding in summer gives the fastest results for commercial production. Seed propagation is not recommended as offspring will not come true. Overall propagation difficulty is rated moderate, with cuttings being the most accessible method for home gardeners.

Diseases & Pests

Altissimo has excellent disease resistance, particularly against black spot and powdery mildew, which is unusual for a red climbing rose. Rust can occasionally appear in humid conditions but is rarely severe. Aphids may colonize young shoots in spring; control with a strong water spray or insecticidal soap. Japanese beetles are attracted to the open blooms in affected regions. Spider mites can be problematic on hot, dry walls. Overall, Altissimo requires far less chemical intervention than most red climbers.

Cut Flowers & Exhibition

Cut Altissimo blooms when the bud is just opening and the petals begin to unfurl. Cut in the early morning with a sharp, clean knife. Place stems immediately in warm water with floral preservative. Single-flowered roses have a shorter vase life of four to six days, but the dramatic blooms make stunning, minimalist arrangements. Remove any foliage below the waterline. The open flowers with their golden stamens are particularly striking in shallow bowls.

Collector & Exhibition Notes

Altissimo holds significant collector interest as one of the finest single-flowered climbers ever bred. It is eligible for exhibition in the single-bloom climbing class and frequently wins at regional shows. Show-quality blooms should have fully expanded petals with fresh, undamaged stamens. The vivid red color holds well without bluing. Altissimo is widely available commercially and not considered rare, but its historical importance in Delbard's breeding program gives it heritage value.

Comparison with Similar Roses

Compared to Dublin Bay, another red climber, Altissimo offers single flowers versus Dublin Bay's fully double blooms, and Altissimo has better disease resistance. Against Dortmund, a red single climber with a white eye, Altissimo delivers a purer red without the bicolor pattern and offers a more refined flower form. Compared to Sympathie, Altissimo is shorter and more manageable but sacrifices the lush, fully double flower form for its distinctive single-petaled elegance.

Heritage & Conservation

As a 1966 introduction that remains in strong commercial production, Altissimo is in no danger of being lost to cultivation. It is preserved in the collections of major rose gardens including those at L'Hay-les-Roses near Paris and the Europa-Rosarium in Sangerhausen. The rose represents an important milestone in the rehabilitation of single-flowered roses in modern breeding and is frequently used as a parent in new climber development.

Cultural Significance

Altissimo has become an iconic symbol of French rose breeding artistry and Delbard's philosophy that beauty lies in simplicity. Its name, meaning very high in Italian musical terminology, connects it to the performing arts. The rose has been featured in countless garden design books and magazines as the quintessential example of how a single-flowered rose can outshine more complex blooms. It holds no particular culinary or medicinal significance but is treasured in gardens worldwide as a design classic.

Frequently Asked Questions