The cymbidium species can be broadly grouped on the basis of their cultural requirments.
These groupings are as follows: -
Large flowered Himalayan group.
Small flowered lowland tropical group
Small flowered temperate group.
The groups will now be discussed in detail.
A. LARGE FLOWERED HIMALAYAN GROUP.
This group contains two sections.
a. Cool growing species, tracyanum, iridioides, erythraeum, hookerianum, wilsonii,
lowianum, schroderi, insigne, sanderae, parishii, elegans, cochleare, and whiteae.
b. Species requiring slightly warmer conditions than the above species are eburneum,
roseum, mastersii, erythrostylum, sigmoideum and tigrinum.
All of these species are distributed from the Himalayas of northern India and Nepal
to the mountains of SW China and south into Indo-China.
They all grow at higher altitudes, from about 1200 to 2800 metres above sea level.
They mostly grow on the larger branches of trees in damp montane forest, amongst epiphytic ferns and mosses. The
largest specimens are commonly found in hollows in the presence of rotting wood, and in the forks of branches where
leaf litter accumulates. They are also sometimes found growing on the ground as lithophytes. The climate of this
environment is characteristically seasonal, with COOL DRY WINTERS AND WARM WET SUMMERS. Such an environment contrasts
with what we usually experience, warm DRY summers and cool WET winters.
The species flower during the relatively dry sunny early winter to spring. While occasional
frosts can be experienced, the plants are usually well protected by the trees on which they grow, and the roots
are dry enough to prevent rotting. Shortly after flowering the summer monsoonal rain commences, and it is during
these warm damp conditions that most vegetative growth occurs. For their optimum culture, the seasonal nature of
their natural habitats must be duplicated. During the summer, high light levels are desired, but growth is inhibited
when temperatures exceeds 27 degrees celsius. The frequent misting of paths and the plants themselves ensures humidity
is maintained during this period. Flowering is initiated during mid summer, and during this period night temperatures
should not exceed 12 degrees celsius. Higher temperatures will give strong growth, but inhibits flower bud initiation.
For this reason, in this country, most cymbidiums should be placard outside in a bright airy location during summer
to ensure the next seasons flowering.
During autumn and winter, lower temperatures are experienced, as well as lower light
levels. Remove any artificial shading used during the summer, and the watering frequency should be reduced.
The habitat of this group of plants corresponds to HABITAT II as discussed in detail
in the Habitats series.
Most cultivated hybrids respond to these environmental conditions.
SMALL FLOWERED TROPICAL LOWLAND SPECIES
The main species are aloifolium, bicolor, rectum, finlaysonianum, atropurpureum,
borneense, dayanum, hartinahianum, chloranthum, madidum, elongatum, sauvissimum. In addition there is a further
small group characteristically from dryer zones, requiring higher light levels.
These species come from habitats from India and southern China, through Indochina
and Malesia to Australia. In the main they occur at low altitudes, often near sea level although some to reach
up to 2500 metres altitude. In the main they must have warmer growing conditions and good light levels, this last
factor being of particular importance for the last group. Many have very thick leathery (coriaceous) leaves, and
the greater degree of this present, generally the warmer and dryer the plants can be grown. Mostly epiphytes of
the tropical forest, warm, bright humid conditions re required. Good root drainage is important - if free drainage
with good air movement is not maintained, root -and eventually plant - death can occur.
Growing and flowering continuously during the summer months, during this period they
should be well watered and fertilised. Shading is required to maintain an even temperature below 30 degrees Celsius
during the day, and 18 to 20 degrees Celsius at night. Because they light love, they usually do best suspended
near the roof in a glasshouse. Insufficient light during the winter is the usual reason for poor growth, and also
for a lack of flowering.
The main group of plants come from a habitat corresponding to Zone I, and second Group
from habitat zone III.
3. SMALL FLOWERED TEMPERATE GROUP
This group includes floribundum, devonianum, munronianum, sinense, kanran, cyperfolium,
faberi, goeringii, and macrorhizon. Cym ensifolium and lancifolium also occur in the tropical zones.
The majority of this group are distributed from Japan, through Southern china to the
Himalayas of Nepal and northern India. They occur from sea level in temperate areas of Japan, up to 2000 to 3000
metres in southern China and northern India. Mostly terrestrials they are normally found growing in open to dense
woodland, often in deep leaf litter and accumulated detritus. Conditions are always generally damp. They have distinct
seasonality in their growth patterns, but flowering occurs at different times of the year. Because some of the
species have a very wide geographic distribution, optimum culture will be obtained when their natural environment
conditions area best duplicated. It is therefore always helpful if details of their particular habitat can be ascertained
to enable culture to be appropriately adjusted.
In the main these species require cool moist well ventilated growing conditions.
Most of these species are native of Habitat Zone II
as discussed under Habitats.