11g THE ORCHID REVIEW. [APRIL, 1901 
petals of P. superbiens, though there are resemblances to both in shape. 
In fact it is a blend of the four species, and its delicate colours reflect the 
general tint of three of its ancestral parent species. ‘ 
CALENDAR OF OPERATIONS FOR APRIL, 
By J. M. Brack, Streatham. q 
APRIL introduces in all earnestness the Orchid growers’ busy season, and — 
potting operations will now have to be pushed on expeditiously, so as not to 4 
lose the proper season, and the present will be a suitable time to ae 
the important question of compost. I am becoming less and less satisfied 
with large quantities of leaves in the compost for Cattleyas and Leelias, and 
a compost which will suit these will also be found to suit most other E 
epiphital pseudobulbous Orchids, particularly those which require at times 
but little water at the root, and which include most Oncidiums, Brassavolas, — 
Stanhopeas, Catasetums, Dendrobi Epidend Trichopilias, — 
Sophronitis, &c. The using of peat rhizomes instead of crocks was am 
excellent innovation, and this alone will, I think, contribute largely to 
conserving the energy of imported plants. ' 7 
We have lately been re-potting a number of half-grown Cattleya seed- 
lings, for which rhizomes were used as drainage when the plants were 
potted about two years ago, and I was gratified to find the roots in splendid 4 
condition, and the rhizomes nearly as open and springy as when first used. 
Concurrently with the introduction to practice of leaves (or leaf-soil), t 
might be safe to say that there was an increase in the use of sphagnum F 
moss, and soft potting became the order of the day. A compost containiig | 
a large proportion of decaying leaves and sphagnum may be organi a 
tich, but it is one which physically soon collapses, and when we remember 
that most Orchids of the classes enumerated above flower best the second 
and third years after being disturbed, the reason for using a compost which 
will remain sweet, firm, and porous for a number of years is readily apparent: 
A reliable compost for these plants is one composed of two-thirds ba 
of good quality, broken into lumps and with only the dust which falls 
picking removed, one-third sphagnum, and a tenth of the bulk of @ 
leaves, with a good sprinkling of coarse silver sand added. These should 
be thoroughly mixed together, well moistened, and prepared a week oF 9 — 
before using. And I am not quite sure that there is anything to be 
by having any moss at all in the body of the compost ; as an addition to the 
surfacing it may be of considerable value, looking neat and fresh, 
assisting in the irrigation of the plant. But has it any nutritive value 
worth speaking of, and is not its decaying readily in the compost more ® — 
source of weakness than strength ? When a plant is freshly potted, the 
