September 16, 1886. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
243 
16 
th 
17 
F 
18 
S 
19 
SUN 
13th Sunday after Trinity. 
20 
M 
21 
TU 
Royal Horticultural Sooiety Committees at 11 am. Cottagers’ Show 
22 
w 
WHAT COOL ORCHIDS WANT. 
LTHOUGH numbers of Orchids grow and flower 
well in what may bo termed a warm greenhouse 
temperature, it does not follow that they will 
succeed in all greenhouses. It is evident that 
some misunderstanding exists as to the essential 
requirements of Orchids, and it is certain that 
many plants have been ruined in consequence. 
The great majority of Orchids derive their sus¬ 
tenance mainly from the air, and this to be sup¬ 
porting must be moist. Rough fibrous material, such as spongy 
peat and moss, is suitable for the plants, not so much because 
of its innate virtues, but because it is such a good medium 
for holding, so to say, a large volume of moist air. Air fills 
all the interstices in the medium in which the plants are 
established, but if it is dry air they soon assume a sickly hue, 
whereas if it is properly moist they flourish. 
Uniform moisture, such as Orchids delight in, cannot be 
maintained about the roots even by applications of water 
alone in a house having a dry breezy atmosphere. The 
medium employed in potting or basketing may be made 
wet enough at times, but if the air that follows the water— 
and it always does follow it—is dry the benefit conveyed by 
watering is momentary rather than sustained. Dry air, then, 
is inimical to the roots, and it is not less so to the foliage 
and pseudo-bulbs of the plants. Steady sustained moisture 
is the chief requirement of Orchids, the degree of moisture to 
be determined by the season of growth and temperature. 
The atmosphere of even a warm greenhouse in which 
flowering plants generally are maintained in a satisfactory 
condition is quite unsuitable for Orchids. It is too dry for 
them, and to afford the requisite moisture would necessitate 
the house being kept too close for the other occupants. 
Orchids and Ferns will thrive together, but Orchids with 
Pelargoniums is an unnatural alliance. It is not a question 
of temperature alone, for this may be right for both, but of 
moisture in the air, on which success or failure mainly 
depends. 
Many so-called cool Orchids are far better in frames in 
summer than in greenhouses with other plants, because the 
air of the frames can be kept in a far more equable state of 
moisture than is possible on the dry stages of a house and 
with the wind driving through the sashe3. Several Orchids 
succeed excellently in frames in the summer, the plants 
elevated on pots inverted in saucers of water, the ashes 
between the saucers being also moist, at least in dry weather. 
During a dull and damp period and towards the autumn the 
air is naturally damp, and it may not be necessary to syringe 
either the plants, pots, or base on which they stand. Various 
forms of Odontoglossums, Oncidiums, Cypripediums, also 
Lselias, Cymbidiums, Epidendrums, Masdevallias, Coelogynes, 
and sundry other Orchids may be kept in admirable condition 
in frames from early summer till early autumn, and they can 
be much better kept in warm greenhouses in the winter than 
they can in the summer, because in winter they do not 
No. 325.— Vol. XIII., Thikd Series. 
require so much moisture, and the houses can be ventilated 
without throwing the front sashes wide open; indeed a posi¬ 
tion can generally be found for the Orchids where the front 
sashes can be kept closed, but dry air must never rise up 
amongst them from hot-water pipes, or the plants will be 
almost certain to go wrong. A close stage is essential, and 
it must be kept more or less moist according to the weather 
and temperature. In some houses and under the manage¬ 
ment of some persons the plants do not suffer in a tempera¬ 
ture of 45°, but that is fully too low for damp structures, and 
a few degrees more warmth will be found generally advan¬ 
tageous. From 45° to 50° may be regarded as a “ comfort¬ 
able ” night temperature in conservatories in winter, and 
suitable for a great variety of plants besides cool Orchids. 
Many Orchids succeed admirably in well managed 
vineries that are started in February or early March, \ines 
will rest quite well in a temperature of 45°, or a few degrees 
higher; so will cool Orchids. The slightly increased heat 
and moisture that are necessary for starting the Vines also 
gently stimulate the plants, and both Vines and Orchids 
require a steady progressive temperature and increased mois¬ 
ture as growth proceeds. The shade from the Vme3, that 
deepens daily as the sun gains power, suits the plants beneath, 
and the genial moisture that is needed for expediting the 
swelling of the fruit is equally enjoyed by the swelling pseudo¬ 
bulbs. Then as the Grapes colour the gradual reduction of 
moisture is invaluable for the ripening of the fruit above ana 
the plants below. This is practically “ warm greenhouse 
temperature, for greenhouses in summer are as warm as 
vineries; but there is a vast difference as regards atmospheric 
moisture in those structures, and that is exactly the reason 
why Orchids succeed in one case and so often fail in the other. 
Moisture they must have during the season of growth or 
they will make no satisfactory progress, and if they are not 
going forward they will soon go backward, as they cannot 
stand still for long.— Experientia docet. 
It is surprising to me to see doubts cast upon the sue 
cessful cultivation of Orchids amenable to cool treatmen 
when grown in a cool house, and I think when failure occurs 
it must be the cultivator instead of the cool treatment which 
is at fault. The way not to succeed with Orchids amenable 
to “ cool treatment ” is to place them in a greenhouse along 
with Pelargoniums, Fuchsias, and such like plants on a dry 
open stage with a cold harsh current blowing amongst the 
Orchids, and these, further, imperfectly watered. In hun¬ 
dreds of cases cool Orchids have been treated like ordinary 
greenhouse plants, and then the grower coolly says that it is 
the “ cool treatment” which is at fault when the Orchids go 
wrong. . . 
I daresay not one cultivator in a score who is successful 
in the cultivation of cool Orchids will differ from me when I 
say that to cultivate these plants successfully is to subject 
them to cool treatment. Very little artificial heat is required , 
only sufficient to prevent the temperature falling below w > 
and on cold, wet, or foggy days to maintain a buoyant 
atmosphere by dissipating excessive moisture. As the season 
advances the temperature must be allowed to take a natural 
rise. The staging should not be dry and open, but composed 
of slate, and this should be covered with shells, broken cinders, 
or fine coal with the dust sifted out. This should always be 
kept moist, which will cause a genial humidity about t e 
plants. The plants must either bo elevated on pots or ou 
light stage erected about 6 inches above the other; it wou 
then be a double stage. . 
Ventilation is very important. It should be applied at e 
apex of the roof, and in such a manner that a cold draug t 
does not blow on the plants ; this must be especially guar e 
against, and the quantity of air admitted should be deter¬ 
mined by the state of the weather. When the weather is 
mild and moist, or close, more air will be needed than when 
the air is dry, or when a cold cutting wind is blowing, with 
No. 1981 —Vol. LXXV., Old Series 
