Clay soil is usually heavy, wet and hard to dig in the winter but tends to dry out and crack in the summer. However, the soil can be improved and there are plenty of plants happy to live in clay soil. Improve clay soil by:
1. Digging it over in the autumn and leave it in clods(big lumps). The wind and frost will break it down
2. Add bulky organic matter each spring such as manure
3. Add some gravel or grit which helps separate the sticky clay particles - creating gaps for air and water.