Clay soil is the definitive horticultural conundrum – by far the most fertile, easily the hardest to work.
The main problem with an unworked clay soil as far as hedging (and many other) plants are concerned is drainage. Without the addition of grit and organic matter, even Hornbeam can become waterlogged. We looked at this problem in a previous post and how to address it. Once remedial action has been taken, you will be able to grow just about any hedging plant you choose. Meanwhile, there are some hedging plants that are happy in both clay and chalk. These include:
• Escallonia Macrantha AGM
• Euonymus fortunei ‘Emerald ‘n’ Gold’AGM
• Euonymus fortunei ‘Emerald Gaiety’ AGM
• Lonicera nitida
PS: Having mentioned chalky soils, it’s worth noting that Perovskia Blue Spire AGM (Perovskia atriplicifolia ‘Blue Spire’) thrives in poor soil and therefore is particularly at home in chalk.