Climbers and wall shrubs are among the most rewarding plants that you can have in your garden. Yet in many ways they are both underrated and unexploited, too. Few people realize the immense difference that they can make to an unprepossessing wall, or to a dreary and depressing view. And still fewer take advantage of the many different ways you can use them apart from simply pinning them to a wall. A row of shrubs can make an attractive screen from neighbours and also, to some extent, from noise. It can even be a portable one if you put the plants into a long planter or a series of tubs. Climbers, on the other hand, do not just have to climb: they can be planted in pockets of soil to trail off the tops of walls, or they can be used very effectively as ground cover, smothering everything in sight. They do not need walls to cling to, either: clematis and roses look very effective scrambling over a dead tree trunk or, of course, over a pergola.
Grown conventionally, climbers give great value for the very little ground space which theiroccupy. Put against an attractive wall, whether it is brick, stone or timber, they do not compete with, but enhance it. At the same time they can be used to great effect to screen off an unpleasant outlook or to cover an unattractive surface – discoloured concrete for instance- and they are splendid to plant against a utilitarian building such as a garden shed to give it altogether a new look. Backed by a framework of trellis, they can disguise dustbins, coal bunkers and other items we would rather not see, or turn a dull part of the garden into an arbour or a sitting-out area.
Climbers help us to come to terms with some of the less attractive aspects of modern living: they can decorate balconies of high-rise flats, for instance, turning them into hanging gardens; they will soften the stark effects of chain link fencing and other boundaries on brand-new housing estates, and are often used cunningly by architects to help ‘knit’ a new extension on to an older building. So as new gardens tend to get smaller, and growing space is at a premium, it is a pity not to make the most of that other dimension to your plot, the vertical one, and use the space to pack in extraand even fruit.
Given support of some kind or other, climbers and shrubs will keep going for years; they suffer very little from pests and diseases and, once they are established they need surprisingly little attention, apart from occasionalfor or shape. But it is important that you choose the right plant for the right place.
CHOOSING THE PLANTS
Most of the climbers that are grown in this country out of doors have a built-in means of clinging to a support. Some twine themselves round a frame or wires by their growing tips – honeysuckle (lonicera) and the Russian vine (Polygonum baldschuanicum) are two examples of these. Others can climb a wall by themselves, using their aerial roots: both ivy (hedera) and the climbing hydrangea (petiolaris) are able to do this. Others, like the grape vine (vitis) and many clematis cling to any support which they can find with tendrils, rather than growing tips; the (Lathyrus odoratus) is another climber that adheres in this way. Yet another kind of climber – and the Virginia creeper (Parthenocissus quinquefolia) is one – has adhesive disc-like ‘plates’ that will attach themselves to any rough surface to support the plant. Others – and here roses and brambles form the main group – use thorns to spike and catch on to a surface. Most wall shrubs, on the other hand, are self-supporting and need little more than tying back for neatness’ sake.
So, when you are choosing a climber, one of the first things you should take into account is the wall itself. Is it brick, stone or some other solid material, or are you going to have to build a framework and use the plants for screening? Is it attractive, or do you want to cover it up?
The next point to consider when choosing your wall shrubs and climbers is aspect. Many people have the mistaken impression that climbers can only be used on a sunny wall but this is by no means the case. There are a surprisingly large number of plants that can cope with all the varied conditions you find on boundary walls, but it is important to get the right ones for the right place.
A wall or fence that faces north will almost certainly be in deep shade for a great deal of the time, and since the sun seldom reaches the soil beneath, the earth will tend to remain damp and moist. So you must choose climbers that can cope with these conditions.
An east-facing wall is in many ways more of a problem for although it will be likely to get some sun in the early morning, this, combined with frost, can cause blossoms and tenderto ‘burn’ on shrubs such as the camellia for instance. It may also be exposed to harsh prevailing winds at certain times of year.
A south-facing wall will be sunny, it is true, but it will be dry as well and needs climbers that can withstand periods of drought. A west-facing wall, on the other hand, is more sheltered and is kindest of all to your plants so you can take more chances, and try half-hardy plants.
Walls have micro-climates of their own, too, usually giving plants more shelter than they would have in a similar exposed plot. But in city conditions there may be funnels of wind along them, caused by neighbouring high-rise buildings, and shade which you would not normally expect, for the same reason. So study your boundaries carefully before you buy, to make sure exactly what kind of conditions the plants are going to meet.
RATE OF GROWTH
Another factor to take into account when choosing climbers and wall shrubs is how fast you want them to grow, and, of course, how high. Although climbers can be controlled more easily, some wall shrubs can outgrow their welcome if they are basically too large-scale for their surroundings. If you are looking for quick cover in a climber, then you need a rapid, rampant grower like the Russian vine (Polygonum baldschuanicum) which can make 6 m (20 ft) of growth in one summer but needs keeping firmly in check. In small spaces, or if you are prepared to wait, it may pay you to plant a real vine and useor herbaceous climbers, such as the hop (humulus) or the nasturtium (tropaeolum), to brighten the wall as the vine grows.