Alkaline soils are those that have a high pH, usually as a result of being rich in chalk or limestone.
In the UK, these soils are often found on chalk downlands, including areas like the South Downs, Chiltern Hills and Salisbury Plain. If you live in an area with limestone deposits, your soil is also likely to be alkaline.
To be certain of your soil pH, test your soil pH with a kit from the garden centre, or online.
Ericaceous, lime-hating plants shouldn't be planted in alkaline soils, as they can't take up important nutrients like iron.
Discover the best plants for alkaline soils that you can grow, below.