54 PRESENT-DAY GARDENING 
leaves or stable manure. What is known as barren, un- 
reclaimed heath land in some parts of Surrey, has a soil 
which consists almost entirely of very fine sand from which 
chalk is entirely absent, but it is comparatively rich in 
humus. Such is the soil of Haslemere and the surround- 
ing district, where heather and pine flourish. The Rhodo- 
dendron gardens that have been formed on this soil are 
a proof that it suits them. 
Rhododendrons have a close, finely fibrous root-system. 
They are surface rooters ; the roots never extending far, nor 
descending lower than a foot. A soil to suit them must 
be one that is sweet as opposed to sour, must retain 
moisture for a reasonable time, and resist drought. Such 
a soil is generally rich in humus. It is not the chemical 
composition of the soil so much as its mechanical texture 
which decides whether it is suited to any particular plant. 
Fertility is not a question of chemistry so much as one 
of physical properties. A soil that is quickly responsive to 
freshly applied manure is often the best from the cultivator’s 
point of view ; and it is certainly most easily controlled. 
In their native homes many Rhododendrons are 
epiphytes. They therefore obtain nourishment entirely 
from water plus the little humus that is contained in the 
debris which accumulates about their roots. It is quite 
certain that water in which there is no lime supplies nearly 
everything that a Rhododendron requires. In this respect 
the- plants resemble Orchids, and the experience of cultivators 
supports the belief that Rhododendrons, like Orchids, obtain 
pretty well all they require from water. It is difficult to 
say why the presence of lime, either in the water or the 
soil, should have such ill effects on the health of Rhodo- 
dendrons and Orchids. 
