Most prospective customers want to combine their ideal vision of a green façade with this "evergreen" quality. However, the possibilities are somewhat limited, because most evergreen plants often have insignificant flowers etc.. Individual assessment will decide whether the evergreen foliage is more important or a neat and well-cared for appearance during the leafless period is satisfactory.
In our latitudes, the Ivy remains THE evergreen climbing plant par excellence, especially where large areas are to be covered densely. For low greenings along the base of a wall, the Wintercreeper (Euonymous) is an interesting alternative, and matches the ivy in terms of its evergreen appearance. The next best option is the Evergreen Honeysuckle (Lonicera henryi), but that's about it. Most other climbing plants may be "ever"green in milder climates, but mostly they are only "winter"green and often don't provide the desired foliage density.
During harsh winters and without water, though, even the ivy foliage 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 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 during 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 and gradually drops off in the following spring or summer, partly due to a lack of light, because new shoots are growing above the old leaves. This type of deciduous habit goes usually unnoticed.
Occasionally, it suffices 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!
Depending on the harshness of the winter, the leaves of some Clematis and Honeysuckles 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 it 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 the position is, the less this problem occurs. In a mild wine-growing climate it will hardly occur, while at higher altitudes it occurs all the more.
Some climbing plants are characterised by early budding and late leaf drop. 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 in this group.
Occasionally, the question is not so much about green foliage during winter, but rather about an overall well-cared for appearance. This can be achieved with most climbing plants, which are trimmed back in summer. 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.
Even an early winter trim can make for a well-cared 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, as is often done with roses and grapevines, based on a more accurate estimate of potential frost damage.
Without a summer trim, most climbing plants look somewhat messy and unkempt at the beginning of winter. The 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 initially, hence don't appear to be "dead."
The Winter Jasmin also remains graceful without trimming and brightens the rather dull winter season with its small but glowing flowers.
Espaliers or trellis systems contribute significantly to the appearance of climbing plants in winter, whether 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!