What is Hardpan and how is it corrected?
Hardpan is a dense, hard, crust-like soil layer that occurs in some subsoils. It is usually formed by an accumulation of mineral salts and it is virtually impervious to water. Hardpan can also be formed by severe mechanical compaction. The end result is that hardpan blocks drainage. In some situations, it is considered as a structure of value in that it holds water. In most gardens, however, it is considered a major problem. If the hardpan layer is relatively thin and close to the surface, it can be broken up by deep digging. In some situations, it is possible to correct the bulk of the problems by simply poking a series of drainage holes through the hardpan layer using steel rods. Apparently, earth worms present in the subsoil can also penetrate some hardpan layers. If the hardpan can’t be resolved mechanically and the earth worms can’t get through, the remaining option is to use raised beds.
