For most prospective customers, this "evergreen" quality is a part of their vision of an ideal green facade. However, the possibilities are somewhat limited; plants with green winter foliage often have unremarkable flowers. This is not so important for evergreen hedges, but more is usually desired from a wall planting. Individual assessment will decide whether the evergreen foliage is more important, whether "half winter green" is enough, or whether a tidy, well-kept appearance during the leafless period is acceptable in place of winter green.
In our latitudes, ivy is and remains THE evergreen climbing plant par excellence, especially where large areas are to be densely covered. For low greenings along the base of a wall, the winter creeper (Euonymous) is an interesting alternative and matches the ivy in terms of its secure foliage adhesion. The next best option is the evergreen honeysuckle (Lonicera henry). Most other climbing plants may be "ever"green in milder climates, but otherwise only "winter"green and often do not provide the desired foliage density.
During harsh winters and when there is a lack of water, even ivy leaves can wither, while the leaves of the evergreen honeysuckle curl up and gradually drop off, making for a rather bare and sad appearance. This begs the question whether the leafless branches of a deciduous climbing plant wouldn't look more natural and appropriate for that season.
These plants keep their leaves more or less well over the winter, often showing some discolouration or wilting towards the end of winter. The scarlet firethorn (attractive berries!), cotoneaster and blackberry belong to this group. The foliage dries up, withers, and gradually drops off in the spring or summer, partly due to a lack of light caused by new shoots growing over the existing leaves. This type of deciduous habit (leaf shedding) usually goes entirely unnoticed.
It is sometimes sufficient to plant "semi-wintergreen" plants, which will reduce the leafless period from 4-5 to 1-3 months. Akebia and some new, more frequently flowering climbing roses, belong to this group. However, all these plants need a moist soil throughout winter!
With some clematis and honeysuckles, the leaves remain green until the following spring, but often they start to dry up. This may result in a slightly unaesthetic appearance, because at such a late stage, the foliage is no longer shed but rather remains on the plant. If this is undesirable, the leaves have to be removed manually, or else some early winter pruning is required.
The milder and warmer a location is, the less this problem occurs. It will hardly occur in a mild wine-growing climate, but will all the more so at higher altitudes.
Some climbing plants are characterised by early budding (shoots) and late leaf shedding. Although the foliage in these plants is not as long lasting as in the "semi-wintergreen" plants, they may nevertheless be an interesting alternative to extend the green season of a wall or similar. Kiwi and silver lace vine belong to this group.
Sometimes it is not a question of having green leaves in winter, but rather of a generally "cultivated" appearance. This can be achieved with almost all climbing plants, when they receive annual summer pruning. Exceptions are vigorous plants which produce numerous shoots, such as the silver lace vine, which are difficult to keep in check even with a summer trim.
An early winter trim can also make for a well cared-for appearance of a façade greening. For each plant species, one has to consider whether winter pruning is recommended in late autumn or rather towards the end of winter (due to the higher likelihood of frost), as is often the case with roses and grapevines.
Without a summer trim, most climbing plants look somewhat messy and unkempt at the beginning of winter. Dutchman's Pipe belongs to the delightful, low-maintenance exceptions, because even after 2-3 years without a trim, it still looks quite acceptable. This is because this plant has very few shoots but vigorous leaves instead, which will all be shed. Furthermore, the shoots from the previous year remain green for the time being, and thus do no't appear "dead."
Winter Jasmine also remains graceful without trimming, and brightens the rather dull winter season with its small but radiant flowers.
Trellis systems/espaliers contribute significantly to the appearance of climbing plants in winter, whether they are of the classic wooden style, or more contemporary with wire rope, synthetic or other materials. Well designed and sturdily built trellises definitely make the appearance of a leafless climbing plant easier on the eye!