Rather than trying to dramatically amend your garden to fit certain plants that might not like your conditions, it is almost always the best policy to choose plants that suit the conditions in your garden.
In Scotland, soils range from about pH4, which is very acidic, to about pH8, which is alkaline. A pH of around pH6.5 – 7.7 is considered neutral.
That means that if you have acidic soil, you choose plants that love acidic soil. The reason for this is that acid-loving plants require iron, as well as other nutrients, to thrive and they cannot absorb these in alkaline soil.
Do You Have Acidic Soil?
First things first, work out whether you actually do have acidic soil in your garden. The easiest way to check is with a pH test, which is fairly affordable to buy. The pH may vary from one part of your garden to another, so to get reliable results take readings from more than one spot.
You can also do a simple home test to see if your soil is acidic. This will not tell you your exact soil pH level, but could give you more of a clue about the conditions in your garden.
Simply mix some soil with water to make a muddy mix, then add a small amount of bicarbonate of soda. If the baking soda froths up, this dictates that the soil is acidic. If, instead, the soil mix reacts when vinegar is added, then it is alkaline.
Another way to get some clues about the soil in your garden is to simply look around. The plants already growing in your garden and your neighbours’ gardens will help you work out which plants are thriving.
Extremely acidic soil can be problematic because plant nutrients will be washed away more easily, meaning things like phosphate will be less available to plants.
Mildly acidic soil, though, is beneficial and in fact a slightly acidic soil close to 6.5 is said to be the very best pH for gardens.
If the pH shows your soil to be acidic, the plants listed below could all be an excellent choice.
Trees for Acidic Soil
Alder
Acer
Beech
Cedar
Dogwood
Douglas Fir
Magnolia
Rowan
Willow
Shrubs for Acidic Soil
Azalea
Berberis Camellia
Fothergilla
Gardenia
Heather
Holly
Hydrangea
Lithodora diffusa
Magnolia
Pieris japonica
Rhododendron
Flowers for Acidic, Ericaceous Soil
Andromeda polifolia
Begonia
Caladium
Foxglove
Iris
Japanese anemones
Kirengeshoma palmata
Lewisia cotyledon
Liriope muscari (Lilyturf)
Meconopsis cambrica
Trillium erectum
Edible Plants for Acidic Soil
Bilberries
Blueberries
Lingonberry
Cranberry
Gaultheria humifusa (Alpine wintergreen)
Blackberry
Raspberry
If you would like to grow vegetables in the ground in acidic soil then, unless the acidity is particularly extreme, potatoes are likely to be one of the best-performing crops.
Brassicas may not do as well, as members of the cabbage family grow best in slightly alkaline conditions.
Remember that soil pH is only one of the criteria you should look at when choosing plants for your garden, you also need to look at other factors alongside pH to make the right choices.
What if your soil is not acidic but you want to grow acid-loving plants?
Rather than trying to change the soil in your garden, grow acid-loving plants in pots or containers and use ericaceous compost, which is specifically used to support acid-loving plants.
You can also buy plant feed that is specifically designed for ericaceous plants, which will contain all the required nutrients for your plants to flower at their best.
