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How to change your soils pH level

The pH of the soil is the value given to how acidic or alkaline your soil is. If you can remember back to high school science pH is on a scale of 0-14 0 = most acidic 7 = neutral and 14= most alkaline.

Your soils pH level can have a massive impact on plant growth, some plants will thrive in acidic soils while some will only grow in alkaline soils. pH level affects some plants more than others, hydrangeas being a notable lover of acidic soils. If you have some plants that just won’t grow in a certain area of the garden then maybe it is time to investigate the pH level of your soil.

The best way to check the pH of your soil is with a soil testing kit.


Once you know the pH we can begin to change it. Make sure you know the acidity or alkalinity of your soil before taking the next steps or you may just end up making the problem worse! Also research what pH level you want to reach, if you are going azaleas, for example, you will want an acidic soil, if, however, you are growing many common vegetables you will be looking for alkaline soil.

Will my garden be acidic or alkaline?

Without outside intervention by a determined gardener, your soil pH is determined by the type of soil you have and how it formed. The rock type in your area of the country will have a big impact, chalky soils, for example, will be very alkaline.

Another factor that can affect the soil pH is rainfall. Heavy rains will help to wash away nutrients such as calcium and magnesium from soil, leading to it becoming more acidic. If you live in an area with lots of rainfall, and if you don’t you’re one lucky Brit!, then quite often your soil will tend to be more acidic.

How to decrease soil pH

So lets say you’ve tested your soil and now know your soil is too alkaline, how do you bring down the soil pH level? aluminium sulphate and sulphur are two common choices for reducing soil pH.

How to increase soil pH

The most common way of increasing the pH level of the soil is by adding lime. This can be done in numerous different ways and there are many different products on the market to help you increase your soil pH.