36 PLANT PROPAGATION 
where bottom heat applied to newly inserted cuttings 
would prove fatal, but in the majority of instances 
bottom heat, a higher temperature, and closer atmo- 
sphere, are beneficial. The general exceptions are in 
the case of ripened shoots inserted in the autumn and 
wintered in a cold frame or pit; these should be allowed 
first to callus at the base; then a little extra bottom and 
top heat in the spring will stimulate the production of 
roots and top growth. This, however, should not be 
continued indefinitely, but when the young plants be- 
come established gradual hardening-off, free ventilation, 
and ordinary treatment of adult plants should be the 
order. 
‘* Heel” is a term used when speaking of propagation 
by cuttings. It consists of a portion of the older wood 
from which the cutting was taken; this provides a large 
surface from which roots may be protruded, and is just 
sufficiently solidified to be in the right condition for the 
purpose. 
A compost suitable for the majority of cuttings propa- 
gated in pots, pans, and boxes may consist of sifted 
loam and leaf-mould, with a liberal admixture of silver 
or river sand free from iron, the pots being surfaced 
with about 4 inch of pure sand. Peat-loving plants, 
such as Heaths and Epacrises, should have a compost 
of equal parts fine peat and silver sand and the pots 
surfaced with pure sand. In all cases the receptacles, 
whatever used, should be adequately drained with crocks 
or other material, so that there may be no fear of stagna- 
tion, and that the surplus water may drain freely away. 
When inserting the cuttings, whether this be done 
with a dibber or otherwise, care should be taken to press 
the compost close up to the base, so that no hollow air 
