How to Check Acid or Alkaline Levels: Soil fertility and what you can grow, is affected by the pH level, or the amount of lime in the soil. The pH is measured on a scale of 1 to 14. The low numbers denote an acid soil, a neutral soil has a pH of 7 and the higher numbers show that the soil is alkaline or limey. Most soil is slightly acid: a pH of 6.5 is ideal for a wide range of plants, including vegetables. A drop of only one point on the scale shows a soil ten times more acid and a rise of one point shows it to be ten times more alkaline.
When a garden has been cultivated for a long time, the soil tends to become slightly more acid, whereas an alkaline soil is less likely to be affected long-term by the treatment it gets. A soil can be made more alkaline by the application of garden lime, used for improving the soil condition for vegetables.
If the pH falls below 5.0 nutrients are affected. Below this phosphate can become unavailable to plants, the soil becomes more acid and calcium, potassium and magnesium can be washed away. A very alkaline soil is equally hostile to many plants, and can cause nutrients to be 'locked' into the soil. Some plants only survive in acid conditions while others thrive if the soil is alkaline. It helps to know the pH level of your soil and which plants suit it and will thrive.
If your soil is acid you can raise the pH level fairly simply by adding lime. it is important to do this at a different-time from using manure, compost or fertilizer. If these are mixed there is a harmful reaction. If you apply manure in the autumn then leave liming until the early spring, about six weeks before planting. Add only a little lime at a time, then test again later and add more if necessary as it can quickly build up.
Measuring the pH level Use a pH kit or a probe meter to check this. Take samples from around the garden. Follow the instructions for whichever method you use.
Raising the pH on sandy and other acid soils. Divide the area to be limed into l mil yd squares, using pegs anti string and weigh out enough lime for each square. Use gloves or a spade to apply the lime one square at a time, sprinkling it as evenly as possible over the surface.
Raising the pH on clay soil follow the instructions for sandy soil; but thoroughly dig the lime into the soil.
It is hard to make an alkaline soil more acid, although digging in compost and manure helps. Use liquid seaweed foliar spray to provide a quicker method of correcting deficiencies. To create a successful garden choose plants that prefer the natural conditions you have some plants for acid soil
If you have an acid soil you are lucky, as most garden plants thrive in a fairly acid soil, and over- acidity can be easily corrected by the use of lime. A few plants, including most heathers and lilies, must have acid soil and refuse to grow without it. Camellias, azaleas and rhododendrons are among the species that will not tolerate lime
