The soil in any location may be a combination of one or more of the basic types of soil; having a general understanding of the properties of different types of soil can help make appropriate planting choices. It is important to be aware that there may be a difference between the soil exposed to the air and the "subsoil", which lies around a foot underneath. The main way in which subsoil affects the home gardener is that it either permits or restricts the top soil's drainage.
Clay soil is fine-grained, wet (even when well-drained), and has a smooth texture. Its high moisture content makes it difficult to cultivate during high rainfall and throughout the winter. Digging it when it is wet causes it to "pan" like cement, making it extremely tricky to work with. The best method of working with clay soil is to dig it in the autumn and leave it rough in the hope that it will be easier to work with come spring time. An advantage of clay soil is that it is extremely rich in plant food, meaning that during dry spells it creates an effective growing environment for crops. Make sure your clay soil is well drained; a regular application of lime will help prevent stickiness and open up the soil.
Sandy soil is light and dry, containing less than 10 percent clay. It warms up quickly in spring because it is so dry, making it useful for producing early crops. Sandy soil is one of the most desired soil types; it can be worked at any time of the year and is generally easy to cultivate. It is not without its disadvantages, however; it is low in plant foods, coarse-grained and does not retain moisture well.
Loamy soil is considered to be the perfect combination of sandy and clay soil. The sandy element keeps the soil open, enabling the plants' roots to travel through it, and the clay retains sufficient moisture for the plants to thrive. There are different types of loamy soil, depending to the exact ratio of sand to clay. Loamy soil is thought to be the best soil for growing large quantities of plants.
Chalky soil can cause problems for gardeners due to its plant food deficiency and shallowness. A solution is to add organic matter, in large quantities. each year. Chalky soil can be hard to work with during wet weather as the rain makes it sticky and unmanageable. Dry weather can also pose problems; the lack of water makes the soil an inhospitable environment for plants. Due to the chalk present in the soil, plants can become affected by chlorosis, resulting in stunted growth and bright yellow leaves.
Peat soil is typically found in low-lying areas, meaning the risk of waterlogging is high; in extreme cases pipe draining is necessary. Peat soil may be brown or black; brown is easier to work with than black, which is extremely heavy, almost bog-like. Some crops thrive in peat soil that has been worked and limed, such as celery and acid-loving plants like azaleas and rhododendrons.