Acid Soil

Acids are produced when organic matter decays. They become increasingly sour as humus is worked in and chemicals are leached out. Soil acidity is measured by pH. A pH of 7 is neutral; any number above is alkaline any number below is acidic. A home test kit is available from most garden supply stores, so you can test your own soil. NOTE: a quick test goes as follows "wet a soil sample and add a pinch of baking soda. If the mix fizzes, the soil is too acidic for most garden plants and vegetables. Most garden plants prefer slightly acidic soil with a pH between 6 and 6.5. Fruits, vegetables, and flowers such as apples and raspberries, beans and peas, pansies and delphiniums prefer it this way. But other plants like more acid. Azaleas, foxgloves, heather, gardenias, blueberries, and camellias, for example need a soil pH between 4.5 and 6. If you want to lower the acidity in your garden soil, apply 1 to 5 kg of dolomitic limestone per 9m²(2½-10 lb per 100 ft²) of soil, depending on soil type― a heavy(clay) soil will require more amendment than a sandy one. If you need to raise the pH even higher, till the limestone into the top 15cm(6 in) of soil. Another way of sweeting the soil (lowering acidity) is to use ashes from a wood burning stove. Spread 2.5 to 5kg per 9m²(5-10 lb per 100²ft) to raise the pH by one unit. Regions with high rainfall, will have soil that acidifies more quickly, as calcium leaches through the soil. Even if the pH is at the right level sprinkle the soil with limestone, which will slowly work it's way downward.