Only the hardiest plants can survive on east facing wall because an east-facing wall really is a stern test of any plant’s durability. An east wall catches the first warmth of the winter sun, so any plant you put there risks being damaged by rapid thawing after frost and it bears the full brunt of the cold east wind.
Not only are all tender plants out of the question, but most evergreens are as well. Because evergreen plants retain their leaves throughout the year, they are always likely to lose water through them – and the cold, drying winds of winter will be drawing water from the plants at a time when they are not in active growth and when the frozen soil makes it impossible for the roots to make good the loss. Only evergreens with tough, durable leaves, able to provide some protection against water loss, will stand any chance of survival. Moreover, any plant that doesn’t cling tightly to the wall is likely to be blown away or suffer damage from the wind.
Among evergreens the choice is limited to ivies. Even among these durable climbers, the variegated forms cannot be considered totally reliable. Any variegated plant is almost always less tolerant of poor conditions than a normal green one because it has a lower level of energy-generating chlorophyll – the green pigment in plants – and is therefore inevitably less vigorous.
Among deciduous climbers there is more choice. The self-clinging climbing hydrangea, Hydrangea petiolaris, is tough and attractive in leaf and produces greenish-white flowers in early summer. Its relative. Schizophragma hydrangeoides, has even more attractive white flowers and foliage. Celastrus orbiculatus is a tough, twining climber always at its best in the autumn when the leaves turn yellow and provide a foil for the red and golden seed heads (be sure to buy this plant from a reliable supplier, as not all forms are equally dependable at fruiting). Akebia quinata is another fairly vigorous twining climber and produces small, scented purple flowers in early spring. It is partially evergreen, but on an east wall it will almost certainly lose its leaves during winter.
Finally, consider planting one of the most valuable of climbing plants, parthenocissus, of which there are three common and one less frequently seen species. All are suitable for an east-facing wall. Parthenocissus tricuspi-data is the Boston ivy, although it is often incorrectly called Virginia creeper. It has three-lobed. ivy-like leaves that flare into the most vivid red in autumn. The true Virginia creeper is P. quinquefolia, a plant with flve-lobed leaves, but less assertive autumn colour. The most beautiful leaves in the genus are those of P. henryana. which have a rich purple-bronze colour and a silvery tint to the veins.
These three species are self-clinging, but where you want to cover an old wall a better bet is the tendril-forming P. inserta. Curiously, this is the least frequently seen species, but it is just as vigorous and just as easily grown as the others. The only real problem with parthenocissus species in general is that a large plant will drop a huge quantity of leaves in autumn.