Last month we looked at how to identify the soil type of your garden to help you choose the best plants. This time, we’re going to look at the other half of the crucial soil equation – soil PH.
Soil PH is a measure of how acidic or alkaline the soil is. Different plants will thrive in different soil PHs and some plants will struggle if soil is particularly acid or alkaline. It’s useful to test soil PH when you’re planning new planting of flowers, vegetables or fruit. You should also test soil PH if you have a plant with yellowing leaves to see if the soil is the culprit.
Photo by Yoshikazu Takada
There are two ways to identify your soil PH. The first way requires you to have a lovely display of hydrangeas in your garden! Hydrangeas are nature’s soil PH testing kits, as the blossom colour depends on the type of soil you have.
- Blue blossom = acidic soil PH
- Pink blossom = neutral soil PH
- White blossom = alkaline soil PH
The second way to find out soil PH is to carry out a chemical test on the soil. This is the most practical as most of us don’t have a handy hydrangea! You can get a professional soil PH test carried out, but you can also use a home tester kit which are available at garden centres.
If your results come back neutral, this is great as most plants will be fine in this soil. Similarly, alkaline soils don’t throw up many problems. If your soil is very acidic, some plants may struggle, although lime-eating plants like rhododendrons and heathers will thrive.
Once you know your soil type you can treat the soil if it needs improving. Acidic soils can be made more neutral by adding lime and alkaline soils can be made more neutral by adding sulphur or iron sulphate.
