Roses are ideal plants for the facade! In addition to their beautiful foliage, they bring magnificent flowers and present no risk of structural damage. The choice of a rose for trellising is by no means limited to the so-called "climbing roses" -- a somewhat arbitrary name given to rose cultivars with long shoots which allow them to climb on pergolas and rose arches... this doesn't necessarily make them always a good choice for walls. Historical climbing roses are often susceptible to disease on walls, while modern shrub or ground cover roses can often be more suitable. Stem roses can be planted in front of a wall without any trellis.
Climbing rose - latin: Rosa
Roses are sensitive and quite prone to disease. Many historical varieties bred in the industrial age fail today because of poor air quality, i.e. no sulfur oxide which the roses need. On hot facades this problem is intensified; you may need to treat with sulphur and select when possible a robust cultivar -- for example, something from the ADR roses. Because of the small market for climbing roses, there are hardly any new cultivars available, so you may need to go with a hardy shrub rose or a ground-cover rose. To guarantee quality, it is best to buy directly from the nursery, as garden centres and wholesalers often sell their roses under colourful, fancy names for marketing purposes. Inaccurate picture labels are also not uncommon!
Roses need a sunny location, but some varieties (especially those that are susceptible to mildew) may suffer from hot south-facing walls. Partially shaded locations can also be considered. The soil should be sandy and loamy, deep, not too moist and also not dry, with some humus but not too nutrient-rich. Fertilise with potassium (potash) or wood ash until early in the summer. Distance between roses: 1.5 - 4 metres.
Roses are ramblers: they grab onto branches or wires with their thorns to grow higher. Some cultivars tend to 'bald' (lose their leaves) at the base. Height of growth depends on the cultivar-- between 2 and 15 metres. The leaves persist from May to October, with some cultivars keeping their leaves well into March. The flowers open at the extremities of green shoots and come in many colours: yellow, white, pink, apricot, dark red... all shades in between. Some cultivars flower only once, some twice, and some for several months. Often produces green or red rosehip fruits.
The framework can be shaped depending on the growth habit of the particular rose. Generally speaking, the horizontal shoots will produce more flower buds and flower better in the following years. Cutting the older flowers stimulates the development of new flowers and can extend the flowering period. On smaller trellises, the rose can be cut down almost to the ground in winter. When cutting a shoot, always leave a small stub.
Stakes, trellis grids, nets, or wire rope systems can be used for roses. The table at the bottom of the page lists compatible designs. Choose a wire rope trellis in the medium range, maybe even in the easy or light ranges for some, and a heavy or massive trellis for the more fragile cultivars or for larger projects.
Roses are not twiners... rather they 'climb' by catching branches of other plants with their thorns; for this reason, they won't grow very high without a trellis / proper climbing support to pull them up. A horizontal training of the shoots is also a good, or even better, idea (see last 4 photos).