What to grow by soil type

Each and every garden consists of a mixture of different micro-environments. No two gardens offer exactly the same conditions, and this is one of the reasons why gardening is such an exciting hobby.

The soil is the starting point for successful gardening. The old saying ‘The secret lies in the soil’ couldn’t be more right! Your soil type is fundamental in dictating what varieties of plants can be grown and the first thing you need to do is establish which soil you’ll be working with. There are four main types: clay, sand, loam and chalk. The best way to tell which soil you have in your garden is to pick some up and mix it with a little water in the palm of your hand, trying to work it into a small ball.

Soil types

Clay soils

Feel sticky and will work into a ball when mixed with water
Are difficult to work in wet or very dry weather
Are cold and wet in winter but may bake dry in summer
Are slow to warm up in spring
Mostly high in nutrients although some trace elements can be ‘locked up’ by attaching themselves to the clay particles

Sandy soils

Feel gritty and will not hold together when mixed with water to make a ball
Are easy to dig even during wet weather
Are free draining in winter but become dry and dusty in summer
Warm up quickly in spring
Leach nutrients quickly due to the free draining nature of these soils
Sandy soil is often acidic

Loamy soils

Are between clay and sandy soils. The soil may hold together when rolled into a ball if it is a ‘clay loam’ but won’t if the soil is a ‘sandy loam’
Loam soils with a high clay content are known as ‘heavy clay loam’ and those with a high sand and silt content are ‘sandy loam’
Are easy to dig once the surface has dried out
Hold nutrients well and tend not to ‘lock up’ trace elements

Chalky soils

Lumps of white chalk or flint stones are visible in the soil
Are either ‘heavy’ or ‘light’ depending if the soil mixed with the chalk is clay or sand

Alkaline soils

The soil fizzes when added to malt vinegar, showing the calcium carbonate content
These soils are often ‘shallow’ with little depth of top soil

Checking Your Soil pH (acidity)

Once you have established the type of soil that you have, look at the types of existing plants that are growing in your garden or in nearby gardens. Are there lots of Rhododendrons, Azaleas and Camellias, along with Pine trees and blue flowers on Hydrangeas? This is a sure sign that the soil is acidic – a must for ericaceous plants.

What Each pH Means

pH 3.0 to pH 5.0

Very acidic soil
Nutrients are either more soluble, therefore washed away easily, or ‘locked up’ making them unavailable to plants. These soils are deficient in nutrients
Most plants find it difficult to grow in very acid soil
Top tip! Add lime to raise the pH to 5.0

pH 5.1 to pH 6.0

Acid soil
Ideal for lime hating (ericaceous) plants such as Camellias, Heathers, Azaleas and Rhododendrons
Add lime if other plants are grown and for vegetables and fruit

pH 6.1 to pH 7.0

Moderately acid soil
This is the ideal pH for a wide range of plants, except lime hating plants
It is not usually necessary to add anything to the soil to change the pH

pH 7.1 to pH 8.0

Alkaline soil
Iron and manganese become less available to plants leading to yellowing of the leaves (chlorosis)
Iron sulphate and other acidifying agents can be added to reduce the pH. Chalky soils are usually not treatable

What to grow by soil type

Plants for chalky soils

These soils tend to be found around the great chalk downs in the southern half of Britain. Characterised by being well drained, but with high pH, a particular set of plants has developed to make the most of the conditions. These plants will give excellent results on chalky soils:

Trees

Acer campestre
Acer cappadocicum forms
Acer griseum
Acer Negundo forms
Acer platanoides and forms
Acer pseudoplatanus and forms
Aesculus (Horse Chestnut)
Gingko biloba
Populus alba
Betula

Shrubs

Buddleja
Ceanothus in variety
Pyracantha
Chaenomeles
Chimonanthus
Forsythia suspense
Escallonia in variety
Hedera

Plants for clay soils

Clay soils are common across Britain. They tend to be heavy to work, but are frequently rich in nutrients. Gardening on clay can be back breaking to begin with, but with the generous and frequent addition of garden compost and other organic matter, over the years these can be some of the most productive and rewarding soils. Very many garden plants will happily flourish on clay soils, having evolved root structures which are designed to cope with Britain’s most common soil type. We suggest:

Trees

Acer in variety
Malus
Alnus in variety
Betula, some varieties
Prunus
Corylus
Crataegus
Sorbus
Fraxinus

Shrubs

Potentilla
Berberis
Chaenomeles
Prunus Lusitanica
Pyracantha
Corylus
Spiraea
Hedera
Kerria
Weigela
Chaenomeles
Viburnum x burkwoodii
Euonymus fortunei
Forsythia

Conifers

Abies
Taxus
Crytomeria
Taxodium

Plants for lime-free soils

These soils have a low pH and are frequently peaty in texture. Gardeners on lime free soils are usually envied by other less fortunate gardeners since they are able to grow a range of the extravagantly showy plants. Those magical words: Camellias, Rhododendron, Azalea and Ericas – all these plants are taken for granted by lime free soil gardeners. For the rest of us, the plants below are best grown in planters containing ericaceous compost, or in the garden in deep man-made pockets of the same stuff. You could try:

Shrubs

Camellia
Kalmia
Leucothoe
Skimmia
Corylopsis
Magnolia
Enkianthus
Fothergilla
Rhododendron
Azalea
Gaultheria
Hamamelis

Plants for poorly drained soils

Poorly drained soils normally mean that for long periods the water content of the soil is very high. But, as always, nature has found a solution and a range of plants have evolved whose root systems are quite content to remain wet. Our list features plants whose ancient forebears would commonly be found in swamps, marshes and along riverbanks. Consider growing:

Trees

Acer pseudoplatanus
Pyrus
Alnus
Quercus robur
Carpinus betulus
Salix
Populus

Shrubs

Cornus stolonifera varieties
Sambucus
Salix

Conifers

Metasequoia
Taxodium

Plants for moist sites

Wet sites and even swampy conditions can be successfully and attractively planted. Many British native plants originally grew in just such conditions and are well represented in our list of plants. Dogwood, Willow, Ornamental Elders and Mock Orange will all thrive and give an excellent show. Those suitable for swampy conditions are marked (SS).

Trees

Acer negundo
Alnus
Betula nigra
Fraxinus excelsior
Liriodendron
Mespilus germanica
Parrotia
Salix (SS)
Sorbus aucuparia forms

Conifers

Abies
Cedrus deodara
Metasequoia
Taxodium

Shrubs

Amelanchier
Hydrangea
Parrotia persica
Philadelphus in variety
Physocarpus opulifolius
Rhododendron
Salix in variety (SS)
Spiraea in variety
Viburnum rhytidophyllum

Perennials

Astilbe
Lobelia Russian Princess
Caltha
Primula in variety
Hosta
Trollius
Ligularia

Plants for light sandy soils

Sometimes known as ‘nurseryman’s soil’, these soils can be some of the most productive in the country, if properly watered and fertilised. Light sandy soils are quick to warm up in the spring, seldom become waterlogged and are easily worked. The secret of success is never to let the soil become too dry and ensure that good levels of plant food are available.

Trees

Acer campestre
Cercidyphyllum
Acer negundo varieties
Cercis
Acer platanoides
Eucalyptus
Acer pseudoplatanus
Gleditsia
Populus alba forms
Alnus cordata
Betula
Quercus ilex
Robinia

Shrubs

Hypericum
Artemisia
Berberis
Mahonia aquifolium
Ceratostigma
Cistus
Clerodendrum
Potentilla
Cortaderia
Romneya
Cotoneaster Ground Coverers
Salvia

Low to medium growing varieties

Sambucus
Cytisus
Genista
Spiraea
Halimum
Helichrysum

Whatever soil you have, understanding it is an engaging and exciting challenge that adds to the enjoyment of gardening. There really is something for every type of soil – and remember soil which is good in heart and high in nutrients will offer plentiful rewards of beautiful flowers and bountiful fruit and vegetable crops.