I'm no expert on Utricularias, but I have grown a number of Masdevallia
orchids which grow in wet epiphytic environments in the pretty much the
same habitat, elevation and light levels as many epiphytic utricularias.
Masdevallias are
*very* temperature sensitive - they don't like temperatures over 85, and
generally do best when maintained at between 60 and 75. There's lots of
variation between species... but they tend to prefer a 24hr temperature
difference of 15 degrees or so, and very uniform conditions.
The following temperature chart is reproduced with permission from Margaret
and Charles Baker, and was first posted to the Orchid List Digest. It
gives an idea of the daily and seasonal temperature changes in a
mid-altitude (1400 meter) cloud forest in the northern Andes...the sort of
place where lots of Utrics and Masdevallias grow together. It may help in
determining the optimum growing temperatures for these plants. Again, it
may not.
CLIMATE: Station #84265, Loja, Ecuador, Lat. 4.0S, Long. 79.4W,
at 4062 ft. (1238 m). Temperatures are calculated for an
elevation of 4600 ft. (1400 m), resulting in probable extremes
of F (C) and F (C).
N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
F AVG MAX 82 83 84 83 84 85 83 81 82 82 82 82
F AVG MIN 64 63 62 62 61 63 63 63 63 63 62 62
DIURNAL RANGE 18 20 22 21 23 22 20 18 19 19 20 20
RAIN/INCHES 0.2 0.2 0.1 1.3 0.7 0.5 0.9 1.7 1.4 2.1 1.0 0.2
[Note: available moisture is much greater due to condensation
from constant fog and mist. Other cloud forests experience
more actual rainfall.]
HUMIDITY/% N/A
[probably 80% or greater, with daily periods of 100%]
DAYS CLR N/A
RAIN/MM 5 5 3 33 18 13 23 43 36 53 25 5
C AVG MAX 27.8 28.3 28.9 28.3 28.9 29.4 28.3 27.2 27.8 27.8 27.8 27.8
C AVG MIN 17.8 17.3 16.8 16.8 16.2 17.3 17.3 17.3 17.3 17.3 16.8 16.8
DIURNAL RANGE 10.0 11.0 12.1 11.5 12.7 12.1 11.0 9.9 10.5 10.5 11.0 11.0
S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN
Scott Portman
Madison WI