A few ground covers will grow in hard, dry, inhospitable soil, but most of them want something better. Some can be found, in nature, in porous sand, whilst others require rich soil. In between is a range of plants which do fairly well in mediocre soil and which may spread fairly well even when neglected. All of these different types will, however, do better if planted in soil to which humus, in the form of compost, old manure rotted down with litter, or leaf-mould, has been dug in.

Ground covers are planted to beautify the garden not for a season, but for as long as you wish to have them, and spending time and money on the thorough preparation of the soil before planting will ensure healthy, luxurious growth and reduce time and money required for later maintenance.

The roots of the plants go down into the soil in search of nourishment so it is advisable to see that the humus is incorporated in the ground where the roots will settle that is 10 to 30 cm below the surface. Prepare the entire area rather than dig holes for individual plants. This will encourage the roots to spread rapidly and produce more verdant foliage.

If the area to be planted is a large and steep slope it may be necessary to take precautions to prevent erosion until the plants have spread across it. First, where it is practical to do so, reduce the angle of the slope, as a gentle slope looks better than a steep one. If this cannot be done, make small ridges along the slope and set the plants in rows just above the ridges, staggering the plants so that those in one line are not immediately below those in the line above. Should this not prove efficient enough to arrest erosion put a thin layer of straw over the plants and cover the whole area with a light plastic net for a couple of months during the season of heavy rains.

Ground covers which grow well create their own humus in time and so continue to flourish, but, if the plants appear to be suffering from malnutrition, sprinkle a little general garden fertiliser on the soil between the plants and water it in. Poor growth and the yellowing of the leaves of plants is usually an indication that the soil lacks some element they need and calls for a pep-up in the form of fertiliser. Those plants which like acid soil should, however, never be given a general garden fertiliser, as their leaves tend to turn yellow because the soil is not acid enough for them and the application of a general garden fertiliser would make things worse.

Where the soil is even slightly alkaline it is inadvisable to plant ground covers which like acid soil. There are many good ground covers for soil which is not acid.
In some parts of the country the soil is strongly alkaline and this makes it difficult to grow a wide variety of plants, as most of them prefer a soil which is neutral or slightly acid. Filling beds with leaf-mould and compost will make it possible to grow a range of plants, but in time the alkaline water is likely to build up adverse conditions.

Inexpensive soil-testing kits are available and in regions of alkaline soil it is wise to have one of these. Should a test reveal that the soil is becoming too alkaline apply a light application (as lightly as one would apply salt to food) of aluminium sulphate and/or sulphur. Both may be used. Aluminium sulphate acts more quickly than sulphur but the sulphur is longer-lasting in its effect. Always water the ground thoroughly after applying them to produce a more speedy reaction.