To find the pH of your soil you need a soil-testing kit, available at any garden centre. It pays to take three or four samples from the outer edges of the garden as you may have more than one soil type, each favouring different plants and treatments. The test will show whether your samples are acidic (below 7), neutral (7) or alkaline (above 7). Most garden plants favour soil that is slightly acidic at 6.5, but there’s still a good selection of plants for neutral and alkaline soils.
With your pH sorted, discovering your soil type is even easier. Just pick some up. If it’s tightly packed, squeezes into a sticky ball and hangs about on your boots – it’s clay. If it feels gritty, and water runs through it easily – it’s sandy. If you discover the white cliffs of Dover under the surface – it’s chalk.
Clay soil is hard to work. It’s wet and cloggy in winter and bakes rock hard in a dry spell. But it is full of good things and the nutrients your plants need to grow, so don’t despair. You do need to improve its drainage though, so mix in some horticultural grit or coarse sand when planting. Clay soil is usually neutral to acidic too so add lime – ground down calcium – especially if you’re growing brassicas. Turn unplanted ground over in the autumn and leave the frost to break up the big lumps.
Success on sand will depend on how you can help the soil hang on to food and moisture. Adding in compost will help retain water and fertiliser long enough for it to do some good. But this will need to become a regular chore so you may wish to just focus on parts of the garden where you are growing hungry, thirsty plants such as the veg.
Chalky soil can be stony, or sticky and thin, but it’s well-drained and you can work on it most of the year. Bulk it up by adding organic matter. Horse manure, which tends to be full of straw, is good for sticky chalk. As it breaks down relatively quickly, spread it on the surface and leave the earthworms to do their bit. Dig in any left over straw in the spring.
