Clay soil is heavy and tends to hold water, which can lead to problems such as root rot. These conditions pose no problem for a variety of evergreen shrubs; they'll actually thrive in the wet, heavy clay soil. Whether you're looking for an evergreen shrub with colourful flowers, foliage or both, there is a plant to fit almost any landscape design.
Southern waxmyrtle is a hardy evergreen shrub that is able to thrive in wet clay. Waxmyrtle is moderately tolerant of drought conditions with a high tolerance to salt whether it's in the soil or in the air. It prefers full sun to partial shade and can grow outdoors in all UK climates. It can reach a height of up to 7.5 m (25 feet), but is typically 3 to 6 m (10 to 20 feet) tall and wide. This fast-growing shrub has fragrant, olive-green foliage and female plants, if a male is nearby, will produce waxy, blue berries.
Inkberry evergreen shrubs form clumps 1.8 to 3.6 m (6 to 12 feet) high and wide. They have dark-green, shiny foliage. The female plants produce black fruit from September to May and solitary white flowers from May to July. Male shrubs bloom with small clusters of white flowers during the same time. Inkberry shrubs do well in wet clay soils sitting in full sun to partial shade. They are moderately tolerant of drought and can grow anywhere in the UK.
The slender, weeping stems of drooping leucothoe burst with blooms during May and June. The fragrant, waxy, white flowers can get lost in the dense, colourful foliage. Leucothoe is fully evergreen in the south and semi-evergreen in the north where temperatures are cooler. Wet clay soil is no problem for this shrub as long as the soil is acidic and deep with lots of organic matter worked in. It stands 90 cm to 1.8 m (3 to 6 feet) high and wide in partial to dense shade. Drooping leucothoe is hardy in the UK and requires little to no pruning to stay looking good.
Oleander evergreen shrubs thrive in wet clay soil whether it's alkaline or acidic. It thrives in all but the coldest areas of Great Britain but it prefers warm temperatures. Certain cultivars are hardy enough to survive temperatures down to -9.44 degrees Celsius (15 degrees Fahrenheit), but may suffer damage to their foliage. Oleanders are fast-growing, reaching heights of up to 6 m (20 feet) tall and 3 m (10 feet) wide. They prefer full sun and tolerate light shade. The large, summer-blooming flowers come in colours such as pink, white, pale-yellow, red and salmon.