Soil Testing & Improving

Soil Analysis & Testing 

When you first start a new garden, perhaps when you move house, or if you take on an allotment, it helps to do some analysis on your soil to work out what will grow well, and what you might need to do to improve the soil.

First of all, you need to work out what type of soil you’ve got, and whether it’s clay, sandy, loam or chalky. The particles in clay soil are very small, so it tends to hold the water, and get waterlogged. On the plus side, it’s usually very fertile soil. Sandy soil has large particles, so tends to dry out. Loam is in the middle: mid-sized particles that retain nutrients, but don’t get waterlogged. How do you know which you’ve got? Sometimes you can see, but if not, rub a bit between finger and thumb. Clay will make a roll, like a sausage. Sand will feel grainy. 

Chalky soils contain calcium carbonate, which you may see as white lumps. To test for it, drop a little bit of soil into a jar of vinegar. If it fizzes, it contains calcium carbonate.

To test for pH, which will tell you which plants will grow, you can buy a DIY testing kit in most garden centres. However, if you’re really serious about gardening, you may find it’s worth investing in a professional lab analysis of your soil. This will tell you soil type, pH, and also something about which nutrients it contains, so you can feed your plants with a  suitable fertiliser.

Improving Your Soil

Once you know a bit more about your soil, you can work out how to improve it.

For both sandy and clay soils, the best way to improve it is to add organic matter on a regular basis, ideally twice a year in spring and autumn. This could be farmyard manure, home-made compost, or bought compost, perhaps mushroom and manure compost. Mushroom compost is composted straw and animal waste that has been used for growing mushrooms, and been heat-treated to remove spores. Mushroom and manure compost has added manure. Findout more about mushroom compost here.

You can add chemicals to make your soil more acid or alkaline. For example, lime is used to make the soil more alkaline, especially if you’re growing brassicas.

Another way to improve your soil is to buy topsoil. You can obtain top soil from topsoil suppliers, who will often deliver in bulk bags, which are more economical to buy than the small bags available from garden centres. Do try to inspect at least a sample before buying, as the quality can vary. It is available in three levels of quality: premium, general purpose, and economy.

And now you’re ready to start gardening!