APRIL, 1923.] THE ORCHID REVIEW. 126 
WHEN TO RE-POT ODONTOGLOSSUMS. 
r.. cultivators of years gone by used to re-pot their Odontoglossums. 
in the autumn months, a season when root action was most active in 
the majority of the plants then grown. In those days there were only species. 
to consider, and under the conditions then existing in Orchid houses that 
method was probably the best. But in present-day collections, when nearly 
all the Odontoglossums are hybrids possessing a much stronger constitution, 
the old regulations have been done away with, and re-potting is carried on 
in nearly every month of the year. The same remarks apply to Odontiodas,. 
and to other hybrids in which the genus Odontoglossum is concerned in the 
parentage. 
Probably the greatest mistake that an amateur can make is to take in 
hand a batch of plants and re-pot every one, no matter whether they are in 
active growth or not. When the new growth is about two or three inches 
high new roots will be seen working their way through the compost in 
search of nutriment, and this is a favourable opportunity for supplying fresh 
material. The re-potting should not be delayed, for the new roots are brittle 
and easily broken. A glance over the plants every few days will soon detect 
any that are making new growths, and if these can be placed together better 
attention can then be given them. 
Sometimes a new growth will start away before the last-made bulb has 
completed its flower spike, when it is a difficult question for the amateur to 
decide whether he should re-pot at once or wait until the following season is 
over. This is a matter that can only be satisfactorily answered by knowing 
all the conditions. Cultivators who enjoy a favourable climate never miss 
the opportunity of potting a plant whenever necessary, no matter whether 
the flower spike is being produced or not, for so long as the old mass of 
compost is not unreasonably torn to pieces the plant benefits quickly from 
the additional supply of nutriment contained in the new compost. 
Let us consider a plant with a new growth from which roots are being 
formed and just ready for re-potting, but at the same time producing a 
flower spike with buds that may not open until three or four weeks’ time. 
If re-potting is delayed until this flower-spike has been cut the roots will 
have penetrated too far into the old compost to allow much disturbance to 
take place, and the plant is thus forced to remain in its old worn-out com- 
post until another season arrives. The result is a rapid loss of vigour, with 
smaller bulbs. With plants carrying flower spikes, and at the same time in 
a suitable condition for re-potting, amateurs will be well advised to care- 
fully remove any of the decayed compost, replacing it with new, and to 
leave untouched all sound portions of the old material. If a larger pot is 
required there will be a better opportunity of adding fresh compost without 
