Shrubs give a garden its character. With a suitable choice you can have colour all year round as well as many interesting shapes and contrasts. Shrubs, unlike many other garden plants, have a long life and, once established, require little attention while they increase in size and beauty with the passing years.
There are large shrubs and tiny shrubs and shrubs which need walls and fences for support. There are shrubs for all seasons and to suit all tastes. With the right sort of shrubs in your garden, it need never be dull. However, with such a large choice of shrubs, it can be difficult to decide on the ones most suitable for your particular garden. The tables below give a selection of some of those shrubs particularly suitable for certain conditions or with a particular attraction. The most important considerations in making a choice are generally soil, site, temperatures and local weather conditions.
Most shrubs are fortunately indifferent to the alkalinity or acidity of the soil within the limits found in the majority of gardens. There is a group of shrubs, however, which are known as lime-hating or calcifuge, including the camellias, rhododendrons and most of the heathers. When the soil is alkaline, these shrubs are unable to take up certain essential minerals, mainly iron, with the result that they become sickly and suffer from chlorosis, a yellowing of the leaves. The addition of peat and compost to lime soils will gradually make them more acid and consequently more suited to calcifuge plants. But if your soil is distinctly alkaline you will be fighting a losing battle and it is advisable to stick to the majority of shrubs and there are some splendid ones among them – which like alkaline conditions.
Getting the right shrubs to suit your soil is of course only half the battle. The other aspect is climate. The majority of evergreens, for example, like plenty of moisture. If you wish to grow such shrubs in drier, colder areas, frequent watering and regular mulching will be vital to keep the shrubs healthy. Young evergreen shrubs too are likely to need protection in winter until established. A key factor with most shrubs is the amount of cold they can endure. The ability of a shrub to resist cold depends partly on the soil and the site. The floor of a sheltered valley is not the ideal place to grow tender shrubs as cold air runs downhill like water and the lower hollows become pockets for frost and chilling damp fog and mist patches. Freezing winds are more damaging than low temperature, and if the shoots become well ripened, they will withstand more cold than the soft, sappy growth made in dull wet positions. Wet, heavy soil and too much nitrogen fertilizer also encourage the wrong sort of weak growth, whereas well-drained soils, rich in potash help to ensure strong, healthy shrubs.
Apart from the weather, another hazard which faces gardeners in some areas is atmospheric pollution from traffic or local industries. The worst of the noxious gases is sulphur dioxide.