188 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ March 11, 1886. 
countries on the main land. An intermediate house (day temperature 
of the year 60 c to 75°) would be used for the tropical Orchids cf 
America, comprising the Cattleyas, Lselias, and other plants from 
Brazil and the lower parts of Mexico. The third house (day 
temperature of the year 50° to 65°) would answer for most of the 
Odontoglossums and Masdevallias, with other plants from high 
regions in tropical countries. All indoor Orchids can be satisfactorily 
grouped in these three divisions, and in the following notes they will 
be referred to as the warm house, intermediate house, and cool house. 
It should be observed that in general practice there has been a great 
reduction in the temperatures for Orchids, and some very experienced 
growers, like Dr. H. Paterson of Bridge of Allan, rely exclusively 
upon sun heat for the higher summer temperatures, and at that season 
frequently have no artificial heat. There can be no doubt that 
highly heated houses during the winter when we are compelled to 
rest the majority of our Orchids is exceedingly injurious, weakening 
them and rendering them precocious in flowering, and much more 
ljable to the attacks of insects. If strong growth is made and well 
ripened under plentiful sun heat and free ventilation Orchids will 
endure a much lower temperature than is usually supposed, and will 
be far more satisfactory than when roasted, as they were in the early 
stages of Orchid culture. As a general guide to the temperature of 
the year for Orchid houses the following table, which was included 
in the paper read by Mr. James O’Brien before the Orchid Conference 
in 1885, is very useful :— 
Table of Temperatures fob ORCtiiD Houses. 
Month'. 
Warm House. 
East Indian. 
Cattleya, or Inter¬ 
mediate House. 
Cool, or Odonto- 
glossum House. 
Day 
Night 
Day 
Night 
Day 
Night 
Degrees. 
Degrees. 
Degrees. 
Degrees. 
Degrees. 
Degrees. 
January . 
G5—70 
60 
60-65 
55 
50—55 
45 
Feb:uary . 
05-70 
60 
60-65 
55 
50-55 
45 
March. 
65-70 
60 
60-65 
55 
55-60 
50 
Apiil . 
65-70 
60 
60-65 
55 
55-60 
50 
May . 
70-75 
65 
65-70 
60 
60-65 
55 
J une . 
75-80 
70 
70-75 
65 
60-65 
55 
July . 
75-85 
70 
70—80 
65 
60-70 
55 
August . 
75-85 
70 
70-80 
65 
60-70 
55 
Septembar. 
75-80 
70 
70-75 
65 
60-65 
55 
October. 
70-75 
65 
65-70 
60 
60-65 
55 
November. 
65-70 
60 
60 — 65 
55 
50 
December. 
65—70 
60 
60—65 
55 
50—55 
45 
Amateurs are often puzzled as to the quantity of piping to be 
used in a house to maintain a particular temperature ; and though 
these matters are best entrusted to horticultural builders, who will 
give the consideration to the position, exposure, and other circum¬ 
stances bearing on the point, yet a few hints may be useful as a 
guide. . Many formulae are given for the purpose of calculating the 
approximate number of feet of piping necessary, but they are all 
somewhat perplexing and occasionally misleading. The following, 
based on a table by Mr. F. H. Fawkes, has the merit of simplicity, 
and it is, moreover, as nearly correct as any calculation of the kind 
nan be. The length of 4-inch piping named is that needed for each 
1000 cubic feet of internal atmospheric contents, and the temperatures, 
as elsewhere in these notes, are given in degrees Fahrenheit. 
Warmest house, 65° to 80°. Lean-to houses, 55 ft. to 65 ft. 
Spans, 60 ft. to 70 feet. 
Intermediate house, 60° to 75°. Lean-to houses, 50 ft. to 60 ft. 
Spans, 55 ft. to 65 ft. 
Cool house, 50° to 65°. Lean-to houses, 40 ft. to 50 ft. 
Spans, 45 ft. to 55 ft. 
Ihese figures practically correspond with what is usually recom¬ 
mended for span-roof houses of good size—namely, warm house, four 
rows of pipes in each side ; intermediate house, three rows ; and cool 
house, two rows, and from them an idea can be gained as to what 
extent of piping is needed, but it is always advisable to have too 
much than too little, as is proved in houses of all kinds, whether 
devoted to plants or fruits. The greater the radiating surface the 
more regular the temperature, and the less injurious it is to the plants 
in severe weather when it may be necessary to keep the fires going 
briskly. 
It may be observed that if a few particulars are known respecting 
the habitat of newly introduced Orchids it is not difficult to provide 
for their lequirements. The first point is to ascertain the country and 
latitude, then the altitude, and finally any other circumstances, such 
as whether the position is exposed or shaded, and in the case of 
terrestrial Orchids the character of the soil in which they are growing. 
The rule usually given for calculating the depression of temperature 
in ascending mountains is to allow a fall of 1° Fahr. for every 300 
to 3o0 feet of altilude, but the depression is more rapid in the higher 
regions. Thus in the tropics, where the temperature at the ground level 
an elevation of 6 to 7000 feet would be estimated to 
t e o5 ; to 60’. This is, however, necessarily influenced to a great 
extent by the position of the land, whether sloping towards the sun or 
not, also whether the mountains are near the sea or inland ; but an 
approximate idea may be gained of what the plants need. 
CULTURAL MATERIALS. 
Good results in plant culture are largely dependent upon the soil 
employed for them, and too little attention is often paid to the 
subject. For Orchids it is particularly important, and a few notes on 
the principal materials necessary may be useful. 
Peat.— This is a well-known substance used extensively for hard- 
wooded plants, Heaths, &c. ; and for the majority of Orchids it is 
indispensable. It varies greatly in its character, depending chiefly 
upon the nature of the soil where it is obtained and the roots of which 
it is composed. In some places it consists mainly of the roots of 
grasses and a black soil derived from the decomposition of vegetation, 
and is then termed bog peat ; in others it chiefly comprises wild 
Heath roots and finer grasses, and is found in higher districts, a third 
kind being mainly formed of Fern roots and rhizomes, both the last 
named containing a varying proportion of light brownish soil from 
the farther decomposition of the roots, &c. These are the principal 
kinds, but there are many intermediate grades. The bog peat, which 
also generally contains a proportion of sand, is most suitable for 
Heaths and similar plants ; the second kind is used for Ferns, and 
the third is the best for Orchids. For these plants it must abound in 
fibre, and the smaller particles should be shaken out before it is used, 
when it can be broken up into pieces of various sizes according to the 
plants for which it is to be employed, but never very small. If a 
quantity is procured at one time it must be stacked where it will not 
be exposed to the wet, and yet not in a hot position where it will 
become too much dried. When ordering peat intending purchasers 
should state that it is required for Orchids, and tire dealers will then 
know what to supply. 
Sphagnum. — The moss used for Orchids consists mainly of 
Sphagnum obtusifolium, but S. squarrosum, S. acutifolium and 
cuspidatum, with others that have been considered as varieties of one 
species, are also abundant in some districts. These are termed bog 
mosses, and are found in low moist places frequently partly sub¬ 
merged, and are abundant in most parts of Britain. The sphagnum 
serves as a retainer of moisture, and by its decay furnishes something 
for the support of the plan*s grown in it. When received it should 
be spread out on a bench or floor and carefully picked and selected, 
removing all the weeds, leaves, grasses, or foreign substances, and 
divide it into three qualities. The first should consist of the fresh¬ 
growing points of the shoots, which must be preserved for surfacing ; 
the next in freshness will be set aside for chopping up and mixing 
wfith peat for potting; and the third, comprising all the roughest and 
most decayed portions, being employed for covering the drainage in 
the pots before the principal soil is placed in. It should all be kept 
in a damp warm position, especially the first named, to induce growth, 
which soon takes place under favourable circumstances, assuming a 
bright green colour. The chopped sphagnum is sometimes scalded 
with hot water to destroy insects, an\d in any case these must be 
looked after very close'y or they will do much mischief afterwards, 
when they cannot be so readily found. A substance termed Trepho, 
consisting of compressed sphagnum, is prepared and sold by Mr. B. 
Field, 170, Old Kent Road, and has been recommended by several 
Orchid growers for blocks or for potting purposes. The sphag¬ 
num is placed under hydraulic pressure, and thus formed into 
compact firm blocks that can be cut to any size required, which, 
as might be imagined from the nature of the substance, are very 
retentive of moisture. It is employed in this way as blocks to grow 
Orchids upon and for breaking up as a substitute for or an addition to 
peat. It is well worth a trial, and the fact that it is being employed 
by some nurserymen is a sufficient proof of its merit. 
Loam, Charcoal, and Potsherds. —For exotic Orchids loam is 
not much used except for Calanthes, a few Cypripediums, or other 
strong-growing species ; but whenever employed it should he of a 
light fibrous character, heavy and clayey loam being especially 
avoided, and that of a very sandy nature is also unsuitable. It must 
be stacked as for other plants and used in an intermediate state of 
moisture. Charcoal is an important material for mixing with com¬ 
post for many Orchids, and some, like the Phalaenopses and others of 
that character, can be grown in that and potsherds alone The latter 
must be thoroughly cleansed and sorted in different sizes, using the 
largest for the lower drainage in pots and for baskets. 
Manures. —Though ordinary manures have been long used for 
strong-growing Orchids of the Calanthe, Cypripedium insigne, and 
Dendrobium nobile types, they have not come into general use for 
other Orchids, and it is quite evident that although some of the 
character named may be benefited by stimulants, these must be 
employed very sparingly and with great judgment for the majority. 
It is true that many tropical Orchids grow where there is naturally a 
luxuriant vegetation, and the gases arising from the rapid decomposi- 
