274 
OPERATIONS FOR JANUARY. 
methods for economizing this heat, should be one of the chief aims of floricultural 
calendars at the present season, and we therefore offer a few hints which may 
perhaps prove useful to cultivators. 
The principal circumstance which occasions an unnecessary expenditure of heat 
at this time, is one to which we have before called attention, but which cannot 
be too often urged — the improper use of water, or the admission of air that is too 
much charged with moisture. All plants — at least those of a woody nature — 
being now torpid, seldom require watering more than once a week, and then only 
in small quantities. As the circulation of their sap is almost discontinued, and 
their exhalations scarcely perceptible, it is not surprising that they will subsist 
upon an exceedingly sparing supply of water, and this, both for their health and 
safety, should be reduced within the narrowest possible limits. 
After watering the plants in any house, — which should always be done in the 
morning of the day, — a trifling degree of heat should be introduced during the 
ensuing night. This will serve to dry up the water that drains through the pots, 
which would otherwise create an injurious moisture in the atmosphere, and will also 
obviate all danger from any frost that may occur. For, let it be particularly noted 
that, should a slight frost immediately succeed the application of water, more real 
mischief will accrue than from a far greater degree of it at any other time. We 
saw an instance last winter in which a considerable quantity of Pelargoniums had 
been rather liberally watered in mild weather, which continued till three o'clock in 
the following morning, when a frost commenced, which destroyed all their roots 
that were near the edges of the pots, and the plants never properly recovered 
throughout the whole of the past summer. 
This may be sufficient to warn those who rely on any existing state of the 
weather, of the necessity of a moderate supply of artificial heat after water has been 
administered. If the external atmosphere is warm and dry enough on these 
occasions, fires may sometimes be dispensed with, but great watchfulness is 
essential till the increased moisture has been expelled. 
Another mode of moderating the expenses of a garden establishment, is the 
retention of heat in a plant structure by covering the glass. What we have pre- 
viously advanced on this subject must, however, be duly remembered. Any thing 
that is placed in contact with a protected surface, if very porous, is comparatively 
little better than useless ; because, the transference of heat being thus equally 
uninterrupted, it is conducted off with nearly as great rapidity as if the glass were 
exposed, merely having another thin substance to pass through. Mats should, 
consequently, always be elevated on a narrow strip of wood placed at certain 
distances along the house or frame, and fully an inch from its surface ; but care 
must be taken to cover all the apertures round the edges, so as not to leave an open 
space between the mat and the frame, as this would admit of the partial dispersion 
of the heat which escapes through the glass. 
