Clay soil impedes the flow of water, absorbing it slowing and holding onto it for a long time. When wet it’s heavy, sticky and tends to swell, but when dry it shrinks and settles and can be as hard as concrete. It’s made up of closely packed, tiny particles that hold on to water and nutrients. It’s important to add organic matter to improve the structure of the soil. Add peat moss, composted leaves or garden compost to add humic matter and increase pore space. Water moves through clay very slowly, so it is important to use a granular fertilizer in clay soil instead of a water-soluble one. If you have a problem site that stays wet and packed down all the time, consider using natural plant life that prefers clay soils like, Scarlet runner beans, ferns, coreopsis, switch grass, Japanese iris, Black-Eyed Susan, Viburnum, aster, potentilla or Daylily, or even skirting the issue altogether by making raised beds filled with PREMIER® Topsoil or Triple Mix.