Cultural info from Baker's cultural sheet:
The following recommendations are based on averages in the habitat which
should be approximated in cultivation. Reports from growers are included
when they report success with conditions in cultivation that are outside
the range indicated in the habitat.
LIGHT: 3000-4500 fc. Since B. harrisoniae is normally found growing in
exposed locations on east facing cliffs, full morning sun with afternoon
shading is indicated.
TEMPERATURE: Summer days average 77-80F (25-27C), while nights average
66-68F (19-20C), producing a diurnal range of 10-12F (6-7C).
HUMIDITY: 75-80% throughout the year.
WATER: Moderate water is required during the growing season. Care should
be taken to keep water off the leaves of new growths.
FERTILIZER: A balanced fertilizer mixed at 1/4-1/2 recommended strength
should be applied once a week during periods of active growth. After new
growth is mature, use a fertilizer with less nitrogen and more phosphorus
to allow the new growth to harden before winter and to promote better
blooming the following season. To prevent salt buildup during periods of
heavier fertilizer applications, the pot should be leached or flushed
every month or so. This is accomplished by prewetting the media and then
flushing with water equal to twice the volume of the pot.
REST PERIOD: Winter days average 70-72F (21-22C), while nights average
58-60F (14-16C), producing a diurnal range of 10-12F (6-7C). Along with
the cooler temperatures, water should be reduced to occasional misting or
light watering and fertilizer eliminated for about 2 months in winter.
Gradually resume normal water and fertilizer applications when new growth
starts. Successful growers report that these plants should not be treated
too well in winter. They suggest that water and fertilizer applications be
restricted to every second or third time that Cattleyas are watered and
fed. The pseudobulbs should shrink and even shrivel a bit during the
winter rest. In addition, growers indicate that plants should be placed
high in the greenhouse to receive maximum light.
GROWING MEDIA: B. harrisoniae grows well mounted on slabs or rafts if
high humidity can be maintained and sufficient water can be provided.
Medium sized fir bark produces good results for most growers who use pots.
Successful growers suggest that these plants grow well in a potting mix
more like one used for Paphiopedilum than one used with Cattleya. They
further indicate that fir bark with a little coarse sphagnum and some
perlite added produce excellent results.
MISCELLANEOUS NOTES: Because these plants are intolerant of being
disturbed once established, repotting should be done only when necessary
and then only when new root growth is starting. When dividing, each
division should consist of 4-5 pseudobulbs. Growers report that they have
never found what initiates blooming, and that some plants never bloom.
Whether or not they were providing the conditions indicated above is not