Clay Soil Gardening: UK-Suited Plants and Blossoms for Successful Growth in Clay Soil
Clay soil, rich in nutrients and very fertile, can be an excellent medium for a variety of plants. Here's a guide on what to grow, how to improve the soil, and how to care for your plants in this type of soil.
Growing in Clay Soil
A host of plants thrive in clay soil. Among them are climbers like beans, peas, globe artichokes, potatoes, beetroot, parsnips, swedes, turnips, carrots, onions, cabbage, broccoli, Brussels sprouts, kale, cauliflower, kohlrabi, radishes, swedes, turnips, and onions.
For those who enjoy flowers, geraniums such as Geranium × oxonianum 'Wargrave Pink', Geranium macrorrhizum, Geranium 'Ann Folkard', Geranium 'Brookside', Geranium Dragon Heart ('Bremdra'), Geranium Orkney Cherry ('Bremerry'), Geranium phaeum var. phaeum 'Samobor', Geranium 'Mavis Simpson', Geranium Sabani Blue ('Bremigo'), Geranium × johnsonii 'Johnson's Blue', Geranium 'Patricia', Geranium wallichianum Havana Blues ('Noorthava'), Geranium phaeum 'Album', Geranium himalayense 'Gravetye', Geranium pratense 'Storm Cloud', Geranium wallichianum Crystal Lake, Geranium pratense var. pratense f. albiflorum 'Laura', Geranium wallichianum 'Kelly Anne', Geranium 'Orion', Geranium × cantabrigiense 'Ingwersen', Geranium 'Dreamland' ('Bremdream'), and Geranium 'Patricia' are all suitable choices.
However, roses require a lot of water but are susceptible to root rot in clay soil. To combat this, it's recommended to dig a hole deeper and wider than the root ball, surround the roots with organic material, and fill with organic matter and a mix of sand or grit before planting.
Hydrangea macrophylla, or mophead/lacecap hydrangea, is the best type of hydrangea for clay soil. 'Rosa Peace' is a recommended variety for clay soils.
Improving Clay Soil
To improve the texture of clay soil, it is recommended to add organic matter such as leaf mould or mushroom compost rather than manure, which can be too rich. Incorporating a layer (about 5 cm) of horticultural grit and digging it into the top 20 cm of soil helps open up the soil structure.
Improving drainage is critical. Adding gravel mulch (from 10 to 20 cm deep or more) on top or creating a gravel bed with clearly defined edges can greatly enhance soil aeration and water movement, helping plants resist root rot and fungal disease.
Caring for Plants in Clay Soil
Most geraniums need protection from the cold, so it's best to move pots indoors in autumn to ensure they grow back the following year. Geraniums prefer moist but well-drained soil in full sun.
Hardy fuchsias can be cut back in spring and should produce new stems quickly. Fuchsia 'Lady Boothby' is a vigorous variety, producing vibrant red and purple flowers from June until September.
It's important to avoid compacting clay soil when walking on the beds. Mulching generously in spring with well-rotted organic matter, coarse grit, or bark can improve clay soil. It is also important to mulch the base of roses with organic matter.
Plants Suitable for Clay Soil
Acacia binervia 'Sterling Silver' and Banksia 'Giant Candles', resilient to clay conditions, are among the trees that grow well in clay soil. Other trees like green ash, red maple, oak species, white dogwood, and Eastern redbud are also suitable.
Some perennials like geraniums, thalictrums, and astrantia also thrive in clay soils.
In summary, choose clay-tolerant plants and amend the soil with organic matter and grit for better aeration and drainage, supplementing with gravel mulch if possible to improve overall texture and plant health in clay soils.
Growing a variety of plants is possible in clay soil, including climbers such as beans, peas, and flowers like geraniums. For successful gardening in clay soil, it's recommended to enrich the texture with organic matter like leaf mould or mushroom compost, and improve drainage with gravel mulch or a gravel bed.
