How to test your soil pH

How to test your soil pH

Find out how to test your garden soil's pH, in order to choose the most suitable plants to grow.

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In order to get the best out of your garden plants and crops, it’s worth testing your soil pH. In the UK this ranges from 3.5 (strongly acid) to 8.5 (strongly alkaline), with 7 being neutral. Most fruit and vegetables prefer soils that have a neutral to slightly acidic pH.

Discover 10 plants for acid soils and the best plants for alkaline soils.

In addition to pH, you also need to know what texture of soil you have. There are six main types – loamy, clay, sandy, silty, peaty or chalky. Discover how to find out your soil type.

The availability of nutrients, such as calcium, potassium, iron and magnesium, is influenced by pH. In addition, at a pH of 6 to 7.5 the soil organisms that break down organic matter and release nutrients are at their most active. The soil’s pH can also affect the incidence of certain diseases and cultural problems. Clubroot, which attacks brassicas, prefers acid soil, for example, while alkaline soil encourages scab on potatoes.

For a rough indication of your local soil pH, look at what grows well in nearby gardens. If camellias and rhododendrons thrive, the soil is acidic, while flowering cherries, yew and clematis prefer alkaline soils, such as those on chalk.

In this No Fuss Guide, David Hurrion shows how to test the soil in your garden to check whether it is acid, alkaline or neutral. He describes the different kits on the market and shows how to collect the soil from your garden:

Testing your soil is quick and easy – simple pH testing kits are available in most garden centres. Here’s how to do it.


You Will Need

  • Soil testing kit
  • Samples of soil from around your garden

Step 1

It’s important to choose a representative soil sample for testing. Avoid areas that have recently been treated with fertiliser, compost or other materials, as these can affect the reading. Soil pH can vary widely across a garden, so it’s best to test samples from several areas to get an accurate picture.

Adding soil to test tubes
Adding soil to test tubes

Step 2

Remove any stones and twigs from your sample and place the required amount in the tube. Add the chemical solution, shake the contents, and wait until the soil particles settle. Once the liquid clears, compare it against the chart – its colour indicates the pH.

Shaking the soil and chemical solution
Shaking the soil and chemical solution

Step 3

Use the results of this test when choosing which plants to grow in your garden. It will save you the disappointment and wasted effort – not to mention wasted money – of trying to grow plants that will never thrive in your soil.

Soil pH test result
Soil pH test result

Find the right plants

You can find out which plants thrive in acid or alkaline soil by going to our plant database. In the ‘plant search’ facility you can select your soil type and find detailed profiles on a wide range of plants that will enjoy your conditions.

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