Once you have identified the type of soil you have in your garden by looking at its characteristics and its pH, you may discover that instead of being made up of ideal, crumbly loam, it may actually be too sandy, chalky, stony, heavy or acidic. However, if this is the case, don't despair; many such 'problem' soils may be improved with just a little time and effort. There are also a wide variety of plants that are adapted to thrive in almost any conditions; it may simply be a case of finding which ones suit your soil type.

Clay Soils

Clay soils are heavy and sticky when they are wet, but become rock-hard when they are dry, forming a pan or crust on the surface, with moist soil underneath. As clay soils drain poorly, they tend to retain nutrients for longer, making them very fertile.

Clay soils may be improved by cultivation; try double digging the ground when it is dry (turning over two spades depth of soil), incorporating organic matter into the trench. This will improve the soil's structure and its drainage qualities.

• Planting Suggestions: Helen's flower (Helenium), aster, weigela, bergamot (Monarda) and flowering quince (Chaenomeles)

See also:

• Climbers for Clay Soil
• Perennials for Clay Soil
• Shrubs for Clay Soil

Sandy Soils

Sandy soil is free-draining, which means that it tends to dry out rapidly and may lack nutrients. Its texture may be improved by adding bulk to help bind its particles into crumbs, which will retain moisture for longer periods. This may be done by working in large quantities of organic material, such as garden compost, well-rotted manure or mushroom compost, into the soil. This bulky organic matter should also be added into any new planting holes.

• Planting Suggestions: Broom (Cytisus), tulip (Tulipa), tree mallow (Lavatera 'Barnsley'), sun rose (Cistus) and Hibiscus (Hibiscus syriacus).

See also:

• Rock Plants for Sandy Soil
• Annuals for Sandy Soil
• Climbers for Sandy Soil
• Perennials for Sandy Soil
• Shrubs for Sandy Soil

Chalky Soils

Chalky soils are often very pale in colour and highly alkaline. If the soil is relatively shallow over solid chalk or limestone bedrock you may have difficulty in digging holes for plants, as you may hit rock before you reach an appropriate depth. This may also make it difficult for trees to anchor themselves securely as their root systems develop broadly and shallowly, unable to get through the rock. You may need to use a mattock or pickaxe to make tree and shrub holes.

Chalky soils also tend to be free-draining, which combined with their high pH means that they may be deficient in nutrients, especially manganese and iron. Add large quantities of organic material to all planting holes to improve drainage and nutrient content. You should also mulch around all planting with a deep layer of organic material; leaf mould is particularly good for chalky soil.

• Planting Suggestions: Lilac (Syringa), weigela, Madonna lily (Lilium candidum), pink (Dianthus) and mock orange (Philadelphus).

See also:

• Rock Plants for Alkaline Soil
• Annuals for Alkaline Soil
• Climbers for Alkaline Soil
• Perennials for Alkaline Soil
• Shrubs for Alkaline Soil

Acidic Soils

Acid soils have a pH level less than 6.5, and may be sandy, clay or peaty. They are sometimes the result of poor drainage and may be corrected by cultivation and the addition of mushroom compost and lime. However, there are a wide variety of plants that enjoy acidic conditions, and it is often best to simply improve the soils texture and drainage properties, rather than trying to alter its pH.

Sandy soil often needs the addition of bulky material to enable large-leaved ericaceous plants to flourish. Moss peat is the best as it is acidic and breaks down slowly, but coir and garden compost also work well. Avoid using mushroom compost if you want to maintain your soil's acidity.

Many fertilizers are naturally limey and have a harmful effect on ericaceous plantings, so you will need to use one that will not raise the pH. Sulphate of ammonia is a good source of nitrogen (N), superphosphate may be used to supply phosphorus (P) and sulphate of potash can be added to provide potassium (K).

• Planting Suggestions: Heather (Erica), lantern tree (Crinodendron), witch hazel (Hamamelis), camellia and rhododendron.

See also:

• Rock Plants for Acid Soil
• Climbers for Acid Soil
• Perennials for Acid Soil
• Shrubs for Acid Soil

Stony Soils

Very stony soils are difficult to cultivate and do not retain moisture well. Although a small number of rocks that occur in clay and flint combinations can be removed over time, large gravel and pebbles are usually impossible to remove completely.

You can reduce the number of stones appearing on the surface by limiting the amount of cultivation that you carry out on the soil. Organic matter may be added to improve the stone to soil particle ratio; this may be achieved by spreading a thick layer around all plants as a mulch in spring and autumn, and by adding into planting holes. Garden compost may be used, or you can use mushroom compost if your soil is alkaline or moss peat if you want to maintain acidity.

Waterlogged Soils

You can test to see if your ground is waterlogged by digging a hole about 30 cm (12 in) wide, and 45-60 cm (18-24 in) deep and pouring water into it. If the water remains for hours, even days, then the soil is waterlogged. You may not even need to carry out this test; if water lays on the ground for weeks in your garden, then your soil is undoubtedly affected. This may be because the water table is high and the level of water in the soil is naturally near the surface, or it may be due to compaction, hard pan, natural springs, blocked land drains or cracked mains.

Many plants won't thrive in waterlogged soils as the water fills all the tiny spaces within the soil structure, leaving little room for air.

It is important to find out the reason for the high level of water, as some of the causes may be fixed relatively simply by mending or unblocking pipes. However, you may need to install a drainage system. Alternatively, if the waterlogging is confined to a small area, you might want to consider making it a feature by creating a bog garden, and planting it with a range of moisture-loving plants.

• Planting Suggestions: Kingcups (Caltha palustris), purple-loosestrife (Lythrum salicaria), beard fern (Onoclea), flowering fern (Osmunda) and giant rhubarb (Gunnera manicata).