110 
THE FLORIST. 
RADIATION. 
Radiation is one of the greatest enemies of vegetation; it takes place 
with great effect in March, April, and May, when the days are hot 
and the nights cloudless and cold. The heat taken in by the plant by 
day radiates or goes forth by night, when the temperature is often only 
4P or 5*^ above freezing point. Thus the plant loses the day heat, 
amounting to some degrees, when the night is clear, owing to the 
absence of clouds, which are not only the anti-radiators of the world, 
but are also radiators of heat towards the earth. The greatest radiation, 
therefore, takes place when the sky is clear and the wind is N. or 
N.E. Hence the moon, which is an opaque body, having no atmo¬ 
sphere of its own, gets the discredit of ruining vegetation, whereas it 
is perfectly harmless; it has no atmosphere of its own, neither does 
it exercise any influence on our atmosphere, nor cause changes in 
the weather. The weather is as variable at other times as at the 
quarterings of the moon—the difference being simply this, that at the 
quarterings we observe changes of the weather, and at other times we 
observe them not. At the spring of the year, when the moon is full 
and the sky is clear, radiation, after a hot day, takes place, more or less 
frost ensues, and the moon gets the blame. It is not, therefore, the moon 
in April that destroys vegetation, but frost that follows excessive 
radiation, when the sky is cloudless and the air is keen. Certain it is 
that many tender plants and flowers need protection both in winter and 
spring, to prevent their giving off the heat received during the day, 
hence a south wall is a more dangerous place in winter and spring than 
a north wall; the plants under the latter lie in a state of death-like 
abeyance till the dangers are past. Fruit blossoms under a north wall 
often escape without protection, when the unprotected, under a south 
wall, are destroyed. The espalier Apple blossoms in my garden often 
suffer from their early appearance, when the high standards in the 
orchard close by escape, because they have little day heat to give out 
when the night comes on; in a word, they come out when the danger 
is over, or, being fully exposed, take in less heat by day. This leads 
me to return to an old topic, the necessity of covering our south fruit 
walls in spring, especially our Peach blossoms. 
There are of course many ways of covering or mther pretending to 
cover our wall trees; some of the coverings used (rabbit nets!) might 
as well be discarded. The three most successful that I have ever seen 
are the following: First.—Wheat straws hung by the neck close to 
each other, and fixed by driving nails through a long stick against the 
wall; this I saw succeed last year at the lower end of my parish; it 
is, however, fair to say that it was a favourable year for trial. Secondly, 
glass cases which are so abused that I fancy the trees, if they could 
speak, would say, “ I would rather be without you.” The cases should 
be totally removed after the crop is safe, otherwise the wood is drawn, 
weak, and soft, and people are tempted to overcrop the trees, a fault 
that I fear attaches to me ; however, in common life, we do not argue 
against the use of a thing from its abuse. Thirdly, sheets which are 
more like clouds than other coverings are: this is my “ cloud.” They 
