80 Gardening 
with these films and are able to draw water from them 
for the use of the plant. 
Free water in the soil. Ina 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 water. 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. 
