There’s no denying that clay soil can be difficult to work with if you’re unprepared. But with the right knowledge, your garden can really benefit from this soil type! Clay soils are normally present in wetlands and other areas with sufficient rainfall; parts of London, Blackpool, Carlisle, Manchester and Oxfordshire are known for their high clay presence, though there are many other regions in the UK where clay is present.
How to improve clay soil
Clay is a soil that requires ‘improving’ in order to be easier to work with. This means slowly introducing a substance that helps the clay improve in texture, fertility and drainage. For example:
- Adding your own compost will break down the texture of clay soil and open it up, as well as increasing the nutrient value.
- Gypsum will help most clay soils by making it clump together, increasing drainage and making it easier to work with.
- Manure or composted bark can be dug into the soil to make it easier to work and increase fertility.
- Applying organic mulch around trees and shrubs will help the soil to retain moisture in summer and stop it from cracking.
To find out more about clay and other soils, read my blog post here. Otherwise, read on below for my suggestions for plants for heavy clay soil!
1. Mahonia japonica
This medium-sized evergreen shrub produces pale yellow flowers in autumn and winter, and dark blue berries in early spring. It’s well suited to sunny borders in moist but well-drained clay soil.
Well known for performing in clay soil, Hydrangea will bring bright shades of blue, purple, pink or creamy white to your garden! Plant them where they’ll make lots of impact, whether that’s in large pots framing your back door, or in the borders of your front garden to welcome visitors.
3. Malus (crab apple)
With stunning pink flowers in spring and edible fruit in autumn, crab apple trees are ideal for clay soil. Crab apple tree varieties can vary greatly in size; Malus ‘Sun Rival’ is great for small gardens, growing up to 2.5m in height, while Malus ‘Snowcloud’ grows to a mature height of 7m – perfect for sprawling gardens.
4. Viburnum tinus
This large evergreen shrub produces white clusters of flowers during late winter and spring, followed by dark blue berries. With a mature height and spread of 4m by 4m, Viburnum tinus is well suited to deep borders or for use as hedging in clay soil.
Pulmonaria officinalis, or the common lungwort, produce these beautiful blue flowers in late winter to early spring, and is ideal for brightening up clay soil borders early in the season.
Add a bit of cheer to your beds, borders and patio pots with aster. These colourful plants can be perennials or annuals depending on the variety, and produce eye-catching flowers in later summer to autumn.
Another late summer bloomer, Black Eyed Susan (or Rudbeckia) is a cheery plant that requires minimal maintenance. They have a long blooming time (somtimes until the first frost); plus, they attract a range of pollinators to the garden!
8. Liatris spicata
Liatris spicata, also known as Dense Blazing Star or Button Snakewort, puts out feathery, purple spikes in late summer and early autumn. Their grass-like foliage is perfect for sunny, south-facing borders in moist but well-drained clay soil.
9. Echinacea purpurea
Echinaecea purpurea (Purple Coneflowers) are pollinator-attracting plants that look very attractive in the middle part of a clay soil border, perhaps amongst Rudbeckia and Dense Blazing Star! They are ideally suited to full sun, and produce pretty pink blooms from June to September.
10. Daylily (Hemerocallis)
Fans of the daylily will be pleased to know that these plants are tolerant of heavy clay soils. Despite each flower blooming for just a day, the whole plant itself will produce flowers for around four to six weeks when planted in full sun!
11. Miscanthus sinensis
A popular deciduous or evergreen grass, Miscanthus sinensis has a height and spread of 2m by 1.5m. It’s suitable for borders in a range of garden types, from cottage to urban gardens, and can deal with being planted in an exposed area.
12. Hardy geraniums
Hardy Geraniums (cranesbill) are available in a palette of pink, blue and white. They’re super tough plants, growing successfully in a wide range of environments and soils. They’re also self-seeding, and need very little care!
If you didn’t know, roses thrive in clay soil that has been improved with organic matter for better drainage. The plant benefits from the nutrients found in this soil type, so with the right care should produce an abundance of healthy flowers.
14. Syringa vulgaris
Syringa vulgaris, or the Common Lilac, is a tough shrub that produces purple, scented flowers in late spring. It is a cold-tolerant plant that is perfect as a landscaping feature in a sunny border.
15. Bergenia cordifolia
Bergenia cordifolia (heart-leaf bergenia) is wonderfully low maintenance and thrives in moist-but-well-drained clay soil and shaded positions. Its deep green leaves turn auburn in winter, and it produces bursts of pink flowers in spring.
16. Ribes sanguineum
Also known as the Flowering Currant, this plant is a deciduous or evergreen shrub that can grown up to two metres in height and spread. With yellow-green foliage, prink flowers in spring and dark-coloured fruit in summer, this is a vibrant shrub for clay soil gardens.
17. Thuja plicata
The Thuja plicata, or Western Red Cedar, is a magnificent tree for large gardens, with some growing up to 35 metres in height. It’s a fast-growing evergreen with glossy, fragrant foliage and small cones. Ideal in clay soil, use this tree as a focal point or for hedging or screening.
Well known for attracting butterflies, Buddleja produce fragrant pink, purple, blue or white flowers and look wonderful in informal or cottage gardens. Grow them in borders or, for more compact varieties, large patio pots to bring interest to seating areas!
These iconic flowers are beloved by many, and with over 3,000 varieties available, there’s one for every garden. Suiting full sun or partial shade, Fuchsia are best placed in fertile and moist-but-well-drained soil, with is why improved clay is ideal for this plant.
This low mainenance shrub blooms profusely throughout spring and summer, and suits clay soil to a tee. Position this magnificent focal plant in an area with full sun to get the most out of its blooming power, and prune regularly to maintain its shape.
See all the sections in my Plant Guide here.