Best plants for clay soil

Clay soils can be challenging, but are among the most fertile. Anne Swithinbank explains how treat clay soils right and reveals those plants that suit them the best

- Anne Swithinbank

OWNERS of gardens on light soils rejoice in being able to grow a wide range of Mediterranean-type plants. Their lavenders, rock roses and pinks are destined to thrive. Those blessed with a good fertile loam will always look a little smug, as they can grow pretty much everything.

Yet what about gardeners on clay? We tend to throw up our hands and pull a wry face, but bearing the burden of clay soil is not the disaster it is made out to be. I would recommend sourcing a copy of Gardening on Clay and Lime by Margery Fish, if only for her opening comment “Wonderful results can be obtained from clay soil and a garden on heavy soil can be one of the most beautiful.” Choice plants like roses and delphiniums love it.

Fertile clay soils

Clay soils are challenging but fertile, their small particles holding water and nutrients well. Problems arise because these particles stick together, with little space for air to circulate. When wet, clay soils are vulnerable to compaction, and when dry, they often crack at the surface and set solid. Yet mulch them regularly with well-rotted organic matter or fork it in during those magical moments when the surface is workable, and the result will be fertile and fibrous.

Always remember that even improved clay soil holds water longer than other types, and a combination of winter wet and cold can spell death to plants that demand better drainage.

French lavenders don’t stand a chance of overwintering in my garden, and in some beds autumn-planted buddlejas have rotted away in their first winter. Crops like raspberries and rhubarb that refused to grow in the lower parts of our kitchen garden take well in beds uphill.