8o Gardening 



with these films and are able to draw water from them 

 for the use of the plant. 



Free water in the soil. In a soil that is poorly drained, 

 the water not only forms a coating over the granules, but 

 it may also fill the spaces between them. This water 

 which fills the spaces between the soil particles and 

 granules is called free w ater. It can be drained off. It 

 is not held in the soil, but is free ; and like the water 

 in a pond or lake, it will flow to a lower level if it 

 has the opportunity. The roots of garden plants cannot 

 live in a soil that continually retains free water, because 

 the water shuts out the air from between the soil granules. 

 There is not enough air present in such a soil to keep 

 the roots alive, and if a garden site is undrained so that 

 the level of the free water is near the surface, the plants 

 will have only a few shallow roots. These will be able 

 to supply only small amounts of water, and in times of 

 heat and drought the plants will suffer. 



Wet soils are cold. Water absorbs more heat in be- 

 coming warm than does soil or air. Hence a soil that is 

 saturated with water remains cold longer than a soil con- 

 taining much air (especially in spring). If the excess of 

 water is removed by drainage, its place is taken by air 

 which may be warmer and which at any rate becomes 

 heated more quickly. 



Soils that are naturally " warm " or " early " are those 

 which hold almost no free water in the upper layers. 

 They are usually well-drained soils or soils of loose 

 texture, like a sandy loam. " Cold " or " late " soils are 

 those that retain much water. They are usually fine- 

 grained, like clay, or are poorly drained or poorly tilled. 



