Drainage
2010-11-16 at 01:00 pm pshipley
Drainage
If your plot suffers from poor drainage even with an improved topsoil, then you may have an underlying problem perhaps a layer of hardpan (impermeable layer of subsoil) underneath your topsoil or perhaps the water table (the upper level of water in the ground under a well drained topsoil at any time) is naturally close to the surface.
It may be in this case that a drainage system may be required, or that the hardpan will need to be broken up. A simple drainage system would require digging small trenches into which pipes are laid leading to a soak-away or other drainage system.
For vegetable growing you are going to need a good 18 inches or 45cm depth of workable, free draining soil (roughly 2 spade depths). If the layer of hardpan is unbreakable or the water level to high, or a drainage system not feasible, then building raised beds may be the answer.
More information on improving drainage to be added soon….