£6 
THE ORCHID REVIEW. [September, 1921. 
CULTURAL NOTES 
to Lt.-Col. Sir George Holford, 
K.C.V.O., Westonbirt. 
0 DONTOGLOSSUMS.—The late summer and early autumn is generally 
regarded as the best season to undertake any necessary potting 
■operations of the plants, both species and hybrids, of this genus: also the 
hybrid families of Odontiodas, Odontonias and Miltoniodas ; the longer and 
oooler nights and moist atmospheric conditions then prevailing afford 
.conditions'favourable for their re-establishment. Repotting is an important 
detail, much depending on when and how it is carried out. In a general 
-collection of these Orchids, at no period of the year are all the plants ready 
for repotting at the same time, therefore no hard and fast rule can be laid 
"down as to when this operation should be performed. Wherever it is 
possible, the best time is, undoubtedly, after that period of inactivity which 
usually follows flowering, when the plants show signs of again starting into 
growth and the roots become active. As regards the method of potting 
and kind of potting material to use, the compost best suited for these plants 
is one similar to that advised in these columns last month for Miltonias. It 
s essential that everything should be thoroughly clean, the pots well- 
drained to ensure a free passage for water, and over-potting rigorously 
avoided. No hard and fast rule can be laid down, but the more vigorous 
the plant and the larger the roots the rougher should be the compost and 
the larger the receptacle. For a month or two after repotting is a critical 
time for these plants, especially for those that have been much disturbed. 
A surface watering with a fine rose-can will often suffice for these, and the 
plants should be placed together and given the shadiest position. In the 
case of those shifted to larger pots without involving much disturbance of 
the ball, the plants will naturally need more moisture to benefit the lower 
sand most active roots, and they should, with any specimens that have not 
been repotted, be allowed to occupy the lightest places in the house. The long 
spell of tropical weather during this summer made it impossible at all times 
to maintain a suitable temperature for cool-growing Orchids, no matter how 
-one tried to temper the burning heat of the sun by shading, ventilating and 
.damping. At Westonbirt, the thermometer in the cool houses has 
frequently registered 95 during the hottest hours of the day. From now 
onwards the nights will be cooler, though the days may be hot and bright, 
therefore with judicious damping and constant attention to ventilation- 
very important details to observe—a more equable temperature and favour¬ 
able atmospheric condition may be maintained. 
O. citrosum.— This beautiful Orchid is not at all difficult to cultivate. 
