34 
THE COTTAGE GARDENER. 
April 
nary sized greenhouse, those which were first operated 
on will require looking over again. The thinning of 
the berries may thus continue at intervals, accord¬ 
ingly as opportunities occur ; hut the final thinning 
should be accomplished before the berries are as 
large as very small peas. One thing we would urge : 
do not by any means overcrop your vines; one bunch 
of truly good grapes is fairly worth half a-dozen in¬ 
ferior hunches. To set forth any precise number of 
bunches on a given vine as the standard, were indeed 
ridiculous. If th£ vines are healthy, we consider 
that whether trained on the long-rod system or on 
the spurring method, whether one vine occupy the 
whole house or six, that from 12 to 16 pounds of 
good grapes from each rafter ought to satisfy any 
amateur with an ordinary greenhouse. Therefore, 
during the thinning process, if too many bunches 
develop themselves — allowing, we will say. one 
pound weight to a bunch on the average—remove 
all above that quantum. One pound per bunch may 
seem a very small affair to some persons, and so it 
is for exhibition purposes ; this, at present, we are 
not writing for: like the cultivation of huge goose¬ 
berries for show, such require a special mode of 
culture. In our advice, we are taking into considera¬ 
tion the defective energies of many vines through 
badly constructed borders; and where such is known 
to be the case, our advice is, rather crop below the 
marie than above. It frequently happens that the 
bunches produce loose straggling shoulders: when 
such is the case, we say cut them away, provided the 
weight before quoted can be anticipated. We have 
frequently known whole bunches badly coloured 
through the extra appurtenance of these unwieldy 
shoulders, especially when there was a sluggish ac¬ 
tion of the root. It must be borne in mind that the 
colouring, and, of course, flavouring, process is mostly 
earned out through the instrumentality of the three 
or four large leaves which accompany the bunch, sup¬ 
posing the shoot to have been pinched or “ stopped,” 
according to usual practice, one joint beyond the show, 
or young bunch. Such leaves can only elaborate a 
given quantity of the cambium or true sap, that 
quantity being dependent on three things :—first, 
the size of the leaves and the capacity of their sap 
vessels; secondly, the extent of their exposure to the 
light; and, thirdly, the supply of sap from their root, 
in order to furnish abundant food for elaboration. 
Temperature of the Greenhouse. — We come now 
to atmospheric temperature during the earlier stages. 
In remarking on this part of the subject, we will 
state both what amount they must have, and also 
what they may have; the first relating principally to 
artificial heat, and the last to solar heat. 'From'the 
period of the young shoot expanding until the bunch 
is fairlv developed, the average temperature should 
range from 55° at night to 65° by day; and from the 
latter period until the first swelling is completed, 60° 
by night and 70° by day must be secured. Now, as 
to what they may have. During the first-named 
stage, the thermometer may be allowed to reach, as 
the highest point, 85° any time between three o’clock 
and five p.m. on any given day. If, however, several 
days are continuously sunny, 'it is well not to persist 
in such a high temperature, but to be content with 
an extreme of 80°. The high temperature before 
quoted, if persisted in for many days, would assuredly 
cause a weak and watery growth ; for the roots (un¬ 
less artificially heated) would not, in a border of some 
45° to 55°, be able to absorb food quickly enough to 
supply the copious elaboration or perspiration which 
would necessarily take place. We do not conceive 
that there is the least occasion to advance the night- 
heat, by artificial means, at any time whatever above 
60°. The vine, like all other plants, enjoys a sort of 
periodical nightly rest, which Nature has wisely pro¬ 
vided, in most climes, by withdrawing the source of 
light and heat; and no elaboration or change of the 
juices, of any value to the system of the vine, can 
take place in darkness; although the heat be in¬ 
creased, such only tends to dissipate the energies of 
the tree. We deem it good culture to reduce the 
amount of heat as soon as the first swelling is com¬ 
pleted. About five degrees of the day-lieat may be 
given up. Indeed, this will necessarily ensue through 
I a more liberal ventilation than was permitted during 
the first stage. 
Ventilation. — No small share of the success in 
grape-growing depends on the mode of aerating the 
house, or “ giving air,” as it is commonly termed. 
Motion, in the internal atmosphere of houses, is 
now universally admitted to have a beneficial effect; 
the only question is. how it should be produced? In 
a future paper we will offer some suggestions on this 
head; for the present Ave will merely offer a feAv cau¬ 
tions. In the first place, Ave say, bring your vines 
up somewhat hardy: that is to say, inure them to 
some amount of air on every possible occasion, from 
the moment the young bud opens. It is, liOAvever, 
deemed necessary by most old practitioners, to keep 
them what is termed “ close” during the first swell¬ 
ing; and we will not dispute that a somewhat larger 
berry may be produced by such means. This course 
is, however, too perilous for us to adAdse it to the 
amateur. We have frequently known vines treated 
on the close system. If two or three days occur to¬ 
gether in which there arises no necessity for giving 
air, and they are kept close, they become tender as a 
matter of course, and more sensitive to every puff of 
Avind; perhaps, on a succeeding day, there occurs a 
bright sun with a piercing wind, and air must be 
given, or the vines will burn; let it be considered, 
then, how tho poor vines have been, what we must 
call, entrapped, under these circumstances. Whilst, 
however, Ave advocate a rather liberal ventilation, let 
it not be thought that we are anxious to admit either 
the chilling current or the boisterous gale. On the 
contrary, we advise that air must be given with very 
great caution at .th e points of ingress during the early 
spring months; indeed, if the front sashes open, and 
they can be graduated, an aperture of half an inch 
Avill suffice at front, on all but airy sunny days. The 
principal amount as to the egress of heated air must 
be at the back : here the ventilation may proceed at 
a liberal rate, especially at any lights where the vines 
are not quite at the back of the house. 
Fires .—The management of the fires is no unim¬ 
portant matter. These should be lighted daily, when 
needed, at two o’clock in the day, and they should be 
suffered to burn briskly until four, when the damper 
should be used, and the fire merely kept in through 
the night; placing as much fuel on at eight o’clock 
in the evening as will be totally consumed soon after 
midnight. Tf any remain the next morning, be sure 
to pull it clean out, and lay the fire ready for lighting 
again in the afternoon. 
More mischief is occasioned by hot flues or pipes 
early in the morning on bright sunny days than’by 
any other cause; for this reason, Ave say, always give 
a little back air before seven o'clock in the morning , be 
it ever so little: this pui’ifies the atmosphere, and 
provides against any danger from binning. 
