Climbing Roses
The breeding of climbing roses has always been something of a lottery. Although the first of the Hybrid Tea roses were valued as repeat-flowering low bushes, some of them mutated and produced climbing forms that were similar in growth habit to their climbing Tea rose ancestors. Other Climbing roses have been raised from crosses between roses that were themselves large-flowered climbers.

One of the most significant of the Climbing roses, ‘Dr W. Van Fleet’ was raised purposely from a cross of a Hybrid Tea with a first-generation hybrid of a wild climber and a Tea rose; it has the large flowers that are associated with Hybrid Teas. ‘New Dawn’, a repeat-flowering sport of ‘Dr W. Van Fleet’ that appeared in 1930, is still one of the most popular Climbing roses both in North America and in Europe; when crossed with Hybrid Teas, it became the ancestor of many modern repeat-flowering climbers, much hardier than the old climbing Teas.

Some of the best examples have arisen by chance. They have even appeared when their breeders were aiming for a low shrub: David Austin’s beautiful Climber ‘Constance Spry’ was raised from a cross of two low-growing parents, one a Gallica and the other a Floribunda. Anyone who is interested in the stories of the breeders of Climbing roses should read Charles Quest-Ritson’s fascinating account, Climbing Roses of the World.

Climbing roses need rich soil and ample water in summer if they are to produce their best flowers. Once-flowering types build up new strong shoots after flowering, so they also need good cultivation to prepare for the following year’s flowers. Repeat-flowering climbers need water and feeding for the second flush of flowers: in Mediterranean climates, such as California, this may coincide with the autumn rains, but in the absence of rain, extra water will be needed.

Pruning can be minimal; simply cut back the old flowering side shoots and any stems that are too weak to flower, tying in any strong new shoots that will eventually replace the older wood. If possible, train some of the shoots horizontally, so that they can flower along their length and build up a good framework. The hardiness of these roses varies according to their parentage; tender varieties can be helped to survive winters that would otherwise be too cold by tying their stems close against a wall.