July 3, 1890. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
1 
W HAT I advanced recently concerning colouring Peaches and 
Nectarines brought out several interesting and instructive 
'facts from esteemed correspondents, and has led to my penning a 
few thoughts and suggestions on colouring Grapes. Perfection 
of colouring in Grapes is a prime condition all gardeners are, 
more or less, ambitious to bring about, but unfortunately many 
more failures than successes must be recorded every season. 
Plenty of growers succeed in growing fine bunches and large well- 
formed berries, only to fail in colouring them properly. At the 
present time many and anxious are the glances cast at the fast 
changing berries. Numerous are the reasons given for the different 
failures, but whether these are wide of the mark or not cannot 
always be decided. I shall state some of my observations, and 
leave others to criticise them if they will. 
If asked to state what I considered the most frequent cause 
of non-colouring in Grapes, including white as well as black 
varieties, I should unhesitatingly assert that overcropping is the 
chief. It is in respect of the important and nerve-trying work 
of reducing the number of bunches on a Yine that the greatest 
judgment is required. There can be no fixed rule laid 
down, so much depending upon the local conditions. What 
might appear a light crop in one instance might really be too 
heavy in another. With everything in first class order at the 
roots, the proper amount of water being duly supplied and neither 
too soon nor too late, one condition being quite as much to be 
avoided as the other, then ought strong Vines to bear and finish 
a great weight of superior fruit. When, however, the border is 
largely composed of poor, loose, non-retentive soil, a heavy crop, 
as understood by market growers, may prove fatal to the prospect 
of colouring the present crop and the show of bunches next season. 
Even worse to deal with are Vines established in an old border 
with the roots nobody knows where, and there are many such, it 
being impossible to properly colour a heavy crop of fruit in this 
case. 
Past experience ought to be the best if not the only guide, but 
previous mistakes are not always profited by. If a Vine fail to 
finish a dozen bunches in good style in one season, where is the 
sense in leaving as many, or perhaps more, in the next year ? Very 
frequently those in charge fail to estimate the extent of their crops 
till the berries are past their stoning period and colouiing fast. 
Then they sometimes start reducing the number of bunches, and 
if this is not a case of locking the stable after the steed has 
vanished, it comes perilously close to it. The best practice to 
pursue is to take good note of what a Vine, if an old one, has pre¬ 
viously proved itself capable or incapable of maturing properly, 
and to early reduce the number of bunches accordingly. As regards 
young Vines, I would suggest that it is wise to undercrop. 
Next to overcropping I would credit red spider with being the 
cause of the greatest number of failures. As it happens, however, 
one is very frequently the consequence of the other, overcropped 
Vines apparently falling the most easy prey to red spider. If all 
accounts are true, and judging from my own observations they 
most probably are, red spider is very prevalent this season, even 
under conditions not usually considered favourable to the in¬ 
crease of these insects. Those parching easterly winds in May, 
accompanied by bright sinshine, seem to bring everything that is 
No. 523.— Vol. XXI., Third Series. 
bad in their wake, red spider being one of the worst of the evils 
due to that cause. Once established on the Vines no amount 
of moisture in the atmosphere, nor even frequent syringing, will 
prevent their spreading, as if they cannot retain their hold on the 
under side of the leaves they take possession of the upper surface. 
Neither does sulphuring the pipes do much good unless as a pre¬ 
ventive in the first instance, while if it is placed on something hot 
enough to generate extra strong fumes—and 1 have met with cases 
where sulphur has been spread over nearly red-hot bricks or a 
thick piece of hot iron—much more harm will be done in a few 
minutes to the foliage than the red spider could effect all the 
season. No, I hold sponging the leaves carefully and repeatedly, if 
need be, to be the best, and I might say the only remedy, this being 
commenced directly the yellow patches caused by the red spider 
are first seen. We use soapy water, and a little sulphur is left on 
the leaves by the sponge. Once let the spider get the upper hand 
and it is a case of good-bye to all prospects of successfully colour¬ 
ing the Grapes. 
Too much heat and not enough air are conditions which 
militate seriously against perfect colouring in all black Grapes, 
and even Muscats would frequently be of superior quality if 
more air was given when they were ripening. Mr. D. Thomson, 
Drumlanrig, long ago advocated giving more air to Grapes when 
they were colouring, and I have to thank him for some of my first 
successes in colouring the Black Hamburgh sufficiently well to gain 
prizes in first class company. Many years ago Mr. Thomson 
advised that a little front ventilation in addition to that at the 
top be given during the night time, and this plan I have adopted 
ever since. When only the top lights are opened a short distance 
the circulation of air in the body of the house is altogether 
insufficient. What is wanted is a fairly brisk circulation or a 
current of air playing about the bunches constantly. A very low 
temperature I do not recommend, as in this case the chemical 
changes in the berries is incomplete, flavour and keeping qualities 
both suffering in consequence. In cold damp weather especially 
we keep the fires going, this improving the circulation and prevent¬ 
ing undue lowness of temperature. I am not very particular as to 
a difference of a few degrees in the heat of a house of Grapes, and 
rarely heed the thermometer. If it feels comfortable on first 
entering, say at about 9 P.M., with a little ventilation both at the 
front and top, that will do. A “ comfortable ” heat would be 
from 60° to 70° according to the state of the outer atmosphere, this 
answering well for both early and late varieties, but even a lower 
temperature and good circulation of air is preferable to a stagnant 
atmosphere. 
In connection with this part of my subject I cannot do better 
than to briefly detail an instructive experience, for which I have 
to thank Mr. T. Smith, Henbury Hill Gardens, near Bristol. This 
observant gardener is quite of my opinion that if Grapes “ had 
a great deal more air passing over them than they have in most 
vineries, there would be fewer examples of imperfect colouring.” 
In corroboration of this theory he describes what took place in a 
curiously constructed house filled with Madresfield Court, the 
ventilation of which is effected, as in the case of too many houses 
hereabouts, by means of wooden cappings running the whole 
length of the house. More air is also admitted by sundry holes 
and shutters, one of the latter opening out of an earlier house. 
“When,” to use his own words, “the Madresfields were colour¬ 
ing these ventilators were always left open, and there was 
draught enough passing through to turn a mill. One bunch of 
Grapes was within 2 feet of this opening, and might frequently 
be seen oscillating to and fro in a most violent manner. Well, that 
bunch when finished was as black as a raven right up to the shank, 
and all the bunch s situated in the direct current of air were better 
coloured than those on either side, the falling off in this respect 
being marked and gradual.” Nothing I can add can convey a more 
impressive lesson than Mr. Smith’s experience, and those who fail 
No. 2170 .—Vol. LXXXIII.. Old Series, 
