Drainage is the passage of water through the soil. The drainage in the vegetable garden will differ from one soil type to another. Sandy soils drain quickly, clay soils drain slowly.

Gardeners should do everything possible to help drainage. If the drainage is restricted, the water will not be able to get away. Water will collect on the surface of the soil. The fruit and vegetables will die and the soil structure will be ruined. This means that it will be difficult to create a seedbed in the future.

To encourage drainage in the kitchen garden:

• avoid walking on the garden, particularly when wet. Make narrow beds, which can be worked from the path. Use a wooden plank to stand on if on the bed.
• keep drains clear and free, so that they take water away
• do not overwater

The water holding capacity of the soil is the ability to hold the water in the soil. It is held by surface tension around the soil particles. The water holding capacity of each soil will vary. Sand is not able to hang onto the water as easily as the clay. So sandy soil drains easily & will need watering more often.
If the gardener understands his own soil he will know when it needs more water to bring it back to its full capacity. He will be able to recognise the state of the soil by the colour, texture and feel of the soil.

Fruit and vegetables need a constant supply of water, so that they can continue to grow happily. If water becomes short (below full capacity), the plants will become stressed, growth will slow down and the plants will be more susceptible to disease