Plants that grow better if given the support of a wall or trellis play a useful part in the landscaping of any plot, large or small, but especially in the very tiny garden where you gain extra space by growing vertically. They also help to soften harsh buildings and solid boundaries but before you completely conceal your property under a jungle of tendrils, there are certain points that ought to be considered.
The term ‘climbing plants’ is generally used to describe any that are suitable for growing against a supportive barrier — wall, fence, trellis, etc., but in fact they really fall into four distinct categories, obtainable in the main from outlets selling other shrubs.
1. Free-standing and self-supporting plants
These are mainly shrubby and would grow perfectly adequately in the open garden, but their habit makes them suitable for standing or training against a wall or fence. They will generally grow taller and spread wider if given such support, and a warm wall can provide a more clement microclimate for less hardy subjects.
Many do not require artificial support, unless you intend some form of formal training, when a system of wires or some trellis should be provided. Examples of shrubs in this category are:
- Pyracantha — evergreen, white flowers, followed by red, orange or yellow berries, suitable for any position. Trains well.
- Cotoneaster horizontalis – Fishbone cotoneaster. Deciduous but has red berries and good autumn colour. A tough shrub for all sites and completely self-supporting.
- Escallonia. This genus is one which varies in hardiness depending on where it is grown. It is perfectly hardy in mild districts and on the coast but does not like cold inland positions, so if given a south or west wall it will grow considerably better. Escallonias are evergreen or semi-evergreen with shiny leaves and pink, red or white tubular flowers.
The dividing line between this type of plant and any other, especially shrubby ones, is very fine, and in theory any shrub which does not object to some formative pruning can be used to disguise a wall.
2. Self-clinging climbers
These stick themselves to the wall with modified aerial roots which act like suckers and require no additional support, for example, ivies (hedera), of which a considerable number are available, with both plain green and variegated leaves. Also in this group are Hydrangea petiolaris, a climbing hydrangea with white flower heads in summer, and Parthenocissus veitchii, the well known Virginia creeper, which turns a brilliant red in autumn.
3. Climbers which support themselves by means of twining stems, leaves or tendnls
Typical examples of these are the well known large-flowered hybrid and smaller-flowered species clematis, the rampant Polygonum baldschuanicum (Russian or mile-a-minute vine) and the various climbing forms of lonicera, the honeysuckle family.
These do not require any tying in usually, but need a trellis or netting to climb on to, or stakes, canes, poles, etc. to twine round.
4. Lax growers requiring training and support – e.g.
The yellow winter and white summer jasmines and most climbing and rambler roses.
First, you must be sure to pick the right plant for the job. It is no good choosing something which grows only 6 feet high if you want to hide an eyesore, and many climbers, given the right conditions, are far too rampant for most house-wall decoration. You will need access to the windows for cleaning and maintenance, so do not plant bushy or prickly things underneath.
If you grow plants up a free-standing trellis, pergola, arch, poles, or similar you often find that you have to renew the support periodically. Even if plastic mesh is used, you generally have to use wooden support stakes driven into the ground to attach it to, and eventually these could rot. You may not find out they are rotten until the whole thing blows over, and then you more or less have to start from scratch in order to sort out all the muddle. The same thing applies if you plant climbers up a dead tree stump – the lot can fall down eventually, demolishing quite a bit of other stuff with it.
Timber trellis is comparatively fragile and the weight of a strong growing plant can distort or even break it down.