What can I plant in clay soil in full sun?

Deep-rooted perennials such as Echinops, Helenium, Persicaria and shrubs like Cornus and Viburnum cope well; they reach into clay's lower moisture once established.

Why does my clay soil crack in summer?

Clay shrinks as it dries, opening fissures that tear fine roots. A thick mulch and added organic matter keep the surface from setting hard and cracking.

Border Builder

Plants for clay soil in full sun

Plants for heavy clay that bakes in full sun.

Clay in full sun swings between two extremes, and that is what catches gardeners out. In winter it sits cold and waterlogged, rotting roots; in summer it bakes to a grey crust and cracks open, shearing fine roots as the gaps widen. Never dig or walk on it when wet, or you will smear it into something close to pottery. Improve it with grit and bulky organic matter worked into the top spade's depth, and mulch thickly to stop the surface setting hard. Plant in autumn so roots establish before the summer bake. The plants here are deep-rooted, robust perennials and shrubs that anchor into clay's moisture reserve and shrug off both the winter wet and the August drought.

Border Builder is a garden border planner for iPhone and iPad. Pick from the 639 plants below and it works them into a full plan: how many of each, where they go, and how the bed reads through the seasons.

639 plants for this

Common questions

What can I plant in clay soil in full sun?: Deep-rooted perennials such as Echinops, Helenium, Persicaria and shrubs like Cornus and Viburnum cope well; they reach into clay's lower moisture once established.
Why does my clay soil crack in summer?: Clay shrinks as it dries, opening fissures that tear fine roots. A thick mulch and added organic matter keep the surface from setting hard and cracking.

Related collections

Plants for full sun Plants for shade Plants for partial shade Plants for clay soil Plants for sandy soil Plants for chalk soil