Characteristics of Different Soil Types


Soil Type:

Before creating a new garden, or improving an old / existing one, the first place to start is with the soil and not the design. The key to success in any garden is to improve the soil by digging it over and incorporating humus, and organic matter into the soil. Before this is done, however it is first necessary to assess the type of soil that you have.

Different types of soil:


Sand, Loamy sand, Sandy loam
These are well drained and aerated and workable for most of the year. They are very light to handle and quick to warm up in spring. Unless they have a very high organic matter content they are prone to drying out too quickly, and additional watering will be needed. This extra watering will also help to wash out the plant foods and lime from the soil, so they are likely to be acid (except for some coastal soils). They are often referred to as “hungry” soils and need lots of extra feeding. With careful management however, they can be amongst the most productive soil types.

Medium loam, Sandy clay loam, Silt Loam
These are the “average” soil types. They achieve a good balance between the ability to be very productive and the minimum of attention. The medium loam group is probably the best in this respect.

Clay, Sandy clay, Clay loam, Silty clay loam, Silty clay, Silt

The texture of a clay soil is one that has small particles, and can be easily formed into a ball when slightly moist. Other obvious indications are puddling on the surface, often yellow and blue in colour, and difficult to dig. Although these soils are difficult to work and manage, they usually have good supplies of plant foods and lime. The main drawbacks are the high water holding capacity (which means they are late to get going in spring) and the effort required to work them. You will need to catch just the right weather conditions to avoid hard work and damage to the soil structure. The use of heavy machinery (and especially rotavators) should be avoided at all costs, particularly when the soil is wet.

Peat moss or Fen Soils.
Provided they are not too acid and have effective sub drainage, these are probably the best natural soils available. They are rich in plant foods, are easily workable and early. It is possible to convert your existing soil into peat type soil by adding large amounts of organic matter. Some of the keenest exhibition growers do just this. It can be time consuming and costly at first, but once you get there life becomes much easier. You must avoid making your soil too acid though, and careful choice of organic matter is needed.

Chalk soils and Limestone Soils
These are the soils that contain a high proportion of chalk or lime. So much in fact, that it overrides their normal particle size classification. They are often very shallow soils, and severely limit the types of plants that can be grown successfully in them. If you have a soil of this type and are not happy with the range of plants it will allow you to grow, probably the best thing you can do is move to a new area and check the soil out first. If you can’t move, the most sensible course of action is to limit yourself to the plants that will grow in chalky soils. Trying to change the soil is usually an uphill struggle and quite expensive.