Gardening

Gerry Daly tells us what to do with high retaining walls.

On a retainer
Such a hilly country — we are bound to have lots of excavations to make a site for houses. When an excavation is made to create a level site for a house, the slope left behind can be quite steep. In this case, high retaining walls are often the necessary solution to keeping the earth safely in position, but how do we go about making these walls sympathetic with the rest of the garden?

High retaining walls are almost always very imposing and dominant. Just by virtue of the fact of what they do, they are very solidly built and tend to be intrusive on the space next to them. But after all, a retaining wall is no more solid than a natural rock face, and Mother Nature has long ago learned how to deal with those. Very many climbing plants simply relish the solid support and easy growing space that a rock face provides, and a retaining wall is no different

Self-clinging plants are the most obvious plants to consider. These are designed by nature to climb sheer rock faces by clinging on with roots or sucker tendrils. There are not many kinds of these plants but they are invaluable, because there is practically no limit to how high they will grow or how wide they will spread, and they need no artificial support.

The climbing vines are among the most popular — Boston ivy and Virginia creeper, both of which will cover any large wall. Both of these are deciduous, but have very good autumn colour and the tracery of twigs offers good cover when bare. The related Henry's vine is a real beauty with silvery leaves. Not a true ivy, the Argentine ivy, Cissus striata, has very good evergreen foliage.

The climbing hydrangea, Hydrangea petiolaris, is a very good with white flowers and superb yellow autumn colour. There is an evergreen climbing hydrangea, called Hydrangea seemanii, that is available but can be hard to find. Schizophragma is a lovely related species, but unfortunately even harder to find. Widely available, ivy is an excellent choice, evergreen and in a range of sizes and various leaf colour patterns. The birdsfoot ivy, Hedera helix 'Pedata' is a real beauty, as is 'Sulphur Heart'.

Non-clinging climbers can be trained on a retaining wall but some form of wires supports or trellis must be provided. If this is done, a wide range of climbers is available, such as the evergreen Clematis armandii, deciduous wisteria, honeysuckle, the nearevergreen rose 'Alberic Barbier', deciduous crimson glory vine, purple grape vine, potato jasmine, common jasmine, evergreen muehlenbeckia and many forms of deciduous clematis and climbing roses.

It is best to mix a number of these flowering climbers, as they are less vigorous that the selfclimbing kinds. They can be planted as close as1.5 metres apart. This strategy gives and extended flowering period, and the retaining wall will simply disappear behind a curtain of foliage and flowers.

Care for the environment: Have your lawn mower serviced

It is surprising how much petrol a lawn mower can use up when cutting a lawn and it is certain that a poorly serviced mower will use much more than it should. Have your mower serviced or at least change the plug and the oil yourself. Even a change of plug can make a big difference, allowing it to run much cleaner on less fuel. Have the blades sharpened to reduce the load on the engine and this last tip goes for electric mower too as they will use mower power with a blunt blade. In this case, it can be a matter of replacing the blade.

Using Garden Tools

Half-moon edging tool
Ahalf-moon edging tool is used for cutting straight edges to a lawn or flower beds or borders set in a lawn area. March is the month to use this tool because the soil is still soft and the edges are easily cut out. Lay a line to keep the edge straight, or curve a line if the edge is undulating. The half-moon edging tool is pushed down into the ground, cutting the sod as it is pushed in. Choose a good solid brand because many of the lighter, cheaper ones are too light and flimsy and they are fiddly to use.

This month in your Garden

• finish off pruning of apple trees
• sow hardy annual flowers outdoors
• plant evergreen trees and shrubs
• tidy flower borders before new growth starts
• complete the pruning of bedding roses
• re-pot house plants in the coming weeks
• give a first disease spray to roses
• begin lawn mowing as early as possible
• apply path and driveway weedkillers
• repair damage to lawn areas
• clip ivy on walls, but check for nests first
• sow sweet peas in pots in a greenhouse
• finish planting bare-root deciduous tree
• divide herbaceous perennial flowers