Banks | Terraces
Gardens take their shape from the ground they occupy. Sloping ground is more interesting to the eye that flat ground, and it also shows off plants better. A gentle sweep of lawn meeting a mixed border at the bottom of the slope, or the trunks of trees ranged up a woodland slope, have more appeal than the same on flat ground.
The effect of a gentle natural slope is spoiled if it is broken by irregular bumps or dips. Moving soil to create sloping ground is a troublesome business, but well worth the effort.
A bank is a steep slope over a relatively small area. They can be created when a house site, or driveway, is cleared on sloping ground, or when a sloping site is cut into terraces. The front of the terrace is usually left as a steep bank, unless a retaining wall is built. Sometimes, steep banks occur naturally.
Artificial mounds of earth can be used to divide a garden and to deflect noise at boundaries. Steep banks are best planted with trees, shrubs and flowering plants near a house. When low-growing plants are used for ground-cover, they will follow the line of the slope. A few upright plants must always be used among them to ‘lift’ the line of planting.
Earthen banks left after site excavation are a very common problem, mainly because they are rarely taken into consideration at the house design and building phase, but can leave few options and real problems afterwards.
Very often, the problem is made worse by the fact that excavation is often limited and the banks are left too close to the house. And the slope is left in one place and not terraced to 'step down' the slope.
The best solution, if not too close to the house, is to plant the bank with a mixture of trees and shrubs. A bank can be largely disguised by planting trees and shrubs, because it is not immediately apparent how tall the trees are ... a 5 metres tall tree on a two-metre bank simply looks like a 7-metre tall tree. If the bank is too close to the house, you will be limited to shrubs and perennial flowers to achieve a similar effect.
Grass lawn is not usually a possibility as the slopes are generally too dangerous to mow.
To establish trees and shrubs, you will have to control all grass and weeds on the banks, either physically or by spraying with Roundup, which does not affect the soil. Weeds must be controlled until the trees and shrubs are well established, usually about 4 or 5 years, using Roundup, and Basta when Roundup-resistant willowherb builds up.
A terrace is a flat area of ground cut into, or built onto, a slope. Usually, terraces are made by both cutting back into the slope and filling out onto it, using the ‘cut’ material to ‘fill’ elsewhere. Terraces can either ascend or descend the slope. They can be very shallow or quite deep.
Even in the smallest gardens, terracing can be both desirable for its ornamental effect and necessary for its practical function of making sloping ground more comfortable for standing or sitting.
Terraces are very pleasant to sit or stand on. The view looking down a series of terraces with flights of steps, or upwards against the facing banks or retaining walls, is always interesting and offers great scope for displaying plants.
If there is a drop of more than one metre from a terrace, for safety reasons, it should have some indication of the edge. This could be a coping, wall, balustrade or plants. The greater the fall, the higher should be the barrier.