ORCHID SPECIES CULTURE
Charles and Margaret Baker

Vandopsis gigantea (Lindl.) Pfitz.  

AKA: Vanda gigantea Lindl., Vanda lindleyana Griff., Fieldia gigantea
Rchb. f., Stauropsis gigantea (Lindl.) Benth and Hook. f.

ORIGIN/HABITAT: Plants are found on Langkawi Island, which is just off the
northwest coast of Malaya, with reports of early collections as far south
as Melaka. Distribution extends northward through peninsular Thailand, the
Tenasserim Range in Burma and Thailand, through northern Thailand and into
southwestern China. Habitat elevations in the southern parts of the range
have not been reported, but topographical maps indicate the highest point
on Langkawi Island is 2887 ft. (880 m). In peninsular Thailand, plants
reportedly are normally found growing on rocks in the hills close to the
sea. In China, plants are distributed in Guangdong, Guangxi, and southern
Yunnan Provinces. They grow on trees or cliffs in forests at 800-4900 ft.
(250-1500 m) and are usually found in association with ants' nests. Grant
reported that in Burma the plants were abundant in the shady jungles
around Tavoy. In other regions, plants are found in full sun. 

CLIMATE: Station #48603, Alor Setar, Malaya, Lat. 6.2N, Long. 100.4E, at
13 ft. (4 m). Temperatures are calculated for an elevation of 2000 ft.
(610 m), resulting in probable extremes of 93F (34C) and 54F (12C). 

N/HEMISPHERE    JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
F AVG MAX        83   85   86   86   83   82   81   81   80   80   81   81
F AVG MIN        64   64   66   67   68   67   67   67   67   67   66   65
DIURNAL RANGE    19   21   20   19   15   15   14   14   13   13   15   16
RAIN/INCHES     2.5  2.2  5.8  9.0 10.7  7.8  7.7 10.4 12.8 11.9  8.1  5.2
HUMIDITY/%       71   66   70   75   79   79   79   79   82   84   83   77
BLOOM SEASON      *   **    *    *    *         *                        *
DAYS CLR @  7AM   5    4    5    2    0    1    1    1    1    1    2    5
DAYS CLR @  1PM   2    2    2    1    0    1    1    1    0    0    1    2
RAIN/MM          64   56  147  229  272  198  196  264  325  302  206  132
C AVG MAX      28.3 29.4 30.0 30.0 28.3 27.9 27.3 27.2 26.7 26.7 27.2 27.2
C AVG MIN      17.8 18.0 19.1 19.7 20.2 19.7 19.7 19.7 19.7 19.7 19.1 18.6
DIURNAL RANGE  10.5 11.4 10.9 10.3  8.1  8.2  7.6  7.5  7.0  7.0  8.1  8.6
S/HEMISPHERE    JUL  AUG  SEP  OCT  NOV  DEC  JAN  FEB  MAR  APR  MAY  JUN

Station #56985, Mengtze, China, Lat. 23.3N. Long. 103.4E, at 4262 ft.
(1299 m). The record high temperature is 97F (36C), and the record low is
28F (-2C). 

N/HEMISPHERE    JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
F AVG MAX        65   67   77   83   85   82   82   81   81   75   73   67
F AVG MIN        45   49   55   61   66   67   68   66   63   59   54   47
DIURNAL RANGE    20   18   22   22   19   15   14   15   18   16   19   20
RAIN/INCHES     0.2  1.0  1.2  1.5  5.4  6.9 10.2  9.3  2.9  2.7  2.2  0.5
HUMIDITY/%       68   69   62   61   64   74   78   79   74   74   71   70
BLOOM SEASON  
DAYS CLR @ 7AM   13   11   13   11    7    2    2    3    5    4   12   14
DAYS CLR @ 1PM   12   10   10   11    3    1    1    1    2    2    7   13
RAIN/MM           5   25   30   38  137  175  259  236   74   69   56   13
C AVG MAX      18.3 19.4 25.0 28.3 29.4 27.8 27.8 27.2 27.2 23.9 22.8 19.4
C AVG MIN       7.2  9.4 12.8 16.1 18.9 19.4 20.0 18.9 17.2 15.0 12.2  8.3
DIURNAL RANGE  11.1 10.0 12.2 12.2 10.5  8.4  7.8  8.3 10.0  8.9 10.6 11.1
S/HEMISPHERE    JUL  AUG  SEP  OCT  NOV  DEC  JAN  FEB  MAR  APR  MAY  JUN

Cultural Recommendations: 

LIGHT: 3000-4000 fc. The reports of various writers indicate that plants
probably adapt to a wide range of light levels. Strong air movement should
be provided at all times. This is particularly important for plants grown
in higher light. 

TEMPERATURES: The data from the Malaya station indicates the warmest
conditions under which this species should be grown. Throughout the year
in this region, days average 80-86F (27-30C), and nights average 64-68F
(18-20C), with a diurnal range of 13-20F (7-11C). In the southwest China
habitat, summer temperatures are about the same as in Malaya, but there is
a marked seasonal variation with much cooler temperatures in winter.
Although cultivated plants should adapt to conditions within this range,
they are usually grown in the warmer conditions indicated by the Malaya
data, and some growers report that plants are very sensitive to cold. 

HUMIDITY: In Malaya, humidity averages 80-85% from late spring through
autumn but drops to 65-70% for 3 months in winter. Conditions in the
Chinese habitat average about 5% drier year-round. The winter conditions
in China are not only drier, but they last for 1-2 months longer. 

WATER: Rainfall in both regions is very heavy during the growing season.
This is followed by a pronounced dry season in winter. The heavy rainfall
season is much longer in the Malaya habitat, and the winter dry season
lasts only about 2 months. In China, rainfall is heavy for only 4-5 months
from late spring to early autumn, and the averages in winter are very low
for 3-4 months. Cultivated plants should be kept evenly moist while
actively growing. Water should be gradually reduced in autumn after new
growths are matured. 

FERTILIZER: A balanced fertilizer mixed at 1/4-1/2 recommended strength
should be applied every week while plants are actively growing. Many
growers prefer to switch from the normal balanced formula and make an
application of high nitrogen fertilizer early in the year when plants are
actively growing. They may then make an application of a high phosphate or
"bloom booster" formula in late summer or autumn in order to promote
flowering. 

REST PERIOD: In the Malaya habitat, there is little seasonal variation in
temperatures. However, in southwest China, winter days average 65-67F
(18-19C), and nights average 45-49F (7-9C), with a diurnal range of 18-20F
(10-11C). A winter dry season is common to both regions, but the one in
the China habitat is longer and drier. While rainfall is low, additional
moisture is available from heavy deposits of dew. Cultivated plants should
be allowed to dry out somewhat in winter, but they should not remain dry
for more than a few days. Occasional mistings on sunny mornings between
waterings may help keep the plants from becoming too dry. Remember that
the cooler the temperatures, the less water the plants will need.
Fertilizer should be reduced or eliminated until new growth starts and
normal watering is resumed in spring. In the habitat, light is highest
during the clear days of the winter dry season. Growers report that plants
do not bloom in Singapore, which has a warm, uniform climate. 

GROWING MEDIA: Plants may be mounted on tree-fern or cork slabs if
humidity is high and plants are watered at least once daily in summer.
Several waterings a day may be necessary for mounted plants during very
hot, dry periods. Because most growers find it difficult to keep mounted
plants moist enough, they are usually grown in hanging pots or baskets
using a very open, fast draining medium Coarse chunks of cork bark, fir
bark or charcoal are frequently used. 

MISCELLANEOUS NOTES: The bloom season shown in the climate table is based
on cultivation records. In nature, plants bloom in spring and summer. 

Plant and Flower Information:

PLANT SIZE AND TYPE: A large, pendent, branching epiphytic plant that may
grow into huge clumps. It is normally much smaller in cultivation.
Collectors reported that one plant was too large to be carried on an
elephant. 

PSEUDOBULB: The plants do not have pseudobulbs, but their stems are about
12 in. (30 cm) long and may be up to 1 in. (2.5 cm) thick. 

LEAVES: To 24 in. (60 cm) long, but usually about 14 in. (35 cm). Only a
few yellowish green leaves are carried on each stem. They are about 2.4
in. (6 cm) wide and are extremely heavy and rigidly leathery. 

INFLORESCENCE: About 14 in. (35 cm) long including the 4 in (10 cm)
raceme. The pendulous to strongly arching inflorescence emerges from the
stem at the base of leaves near the middle of the stem. 

FLOWERS: 6-18 blossoms are carried on each raceme. The flowers are about 3
in. (7.5 cm) in diameter and often last for several months in perfection.
They are very thick and heavy-textured and are vaguely fragrant at times.
The broad, fleshy sepals and petals are pale yellow with red-brown
blotches that appear as rings with lighter colored centers. The yellow lip
has sidelobes that are suffused with purple and a high white keel down the
middle. 

HYBRIDIZING NOTES: Chromosome count 2n = 38. 

REFERENCES: . 

Grant, B. [1895] 1966. Orchids of Burma and the Andaman Islands.
Hanthawaddy Press, Rangoon, Burma. Reprint, Twin Oaks Books, Greenfield,
Wis.

Hamilton, R. 1988. When does it flower? 2nd ed. Robert M. Hamilton, 9211
Beckwith Road, Richmond, B.C., Canada V6X 1V7.

Hawkes, A. [1965] 1987. Encyclopaedia of cultivated orchids. Faber and
Faber, London. 

Holttum, R. 1964. A revised flora of Malaya. vol. 1, Orchids. Government
Printing Office, Singapore.

Kamemoto, H., and R. Sagarik. 1975. Beautiful Thai orchid species. Orchid
Society of Thailand, Aksornsampan Press, Bangkok, Thailand.

Pridgeon, A. ed. 1992. The illustrated encyclopedia of orchids. Timber
Press, Portland, OR. 

Seidenfaden, G., and J. J. Wood. 1992. The orchids of peninsular Malaysia
and Singapore. Published in association with The Royal Botanic Gardens,
Kew and Botanic Gardens, Singapore. Olsen & Olsen, Helstedsvej 10, DK-3480
Fredensborg, Denmark. 

Williams, B. [1894] 1973. Orchid growers' manual. 7th ed. Victoria and
Paradise Nurseries, London. Reprint, Weldon & Wesley, Codicote, Herts,
United Kingdom, and Verlag J. Cramer, Lehre, West Germany.

Veitch, J., and Sons. [1887-1894] 1963, 1981. Manual of orchidaceous
plants, vols. I-II. James Veitch and Sons, Royal Exotic Nursery, Chelsea,
London. Reprint, vol. I, A. Asher and Co., Amsterdam, The Netherlands;
reprint, vol. II, Bishen Singh Mahendra Pal Singh, Dehra Dun, India.

PHOTOS/DRAWINGS: . 


Copyright 1997, Charles O. Baker and Margaret L. Baker
Sheet version 546363

.........................................................................
Please remember that this sheet is for your use only, and though it was
provided free of charge, it may not be reproduced or retransmitted in
any way without permission.
.........................................................................

__________________________________________________________________________
 "Orchid Species Culture" Charles & Margaret Baker, Portland, Oregon USA

    Orchid Culture & Pollination site    http://www.orchidculture.com
                     
                   email <cobaker@troymeyers.com>
__________________________________________________________________________

    "Orchid Species Culture Vol. 1 - Pescatorea, Phaius, Phalaenopsis,
   Pholidota, Phragmipedium, Pleione"  250 pages of culture information.

            "Orchid Species Culture Vol. 2 - Dendrobium"
  850 pages of culture information for more than 1230 Dendrobium species.

  "The genus Paphiopedilum--Natural History and Cultivation" - Part 1
    Dr. Guido Braem, Charles and Margaret Baker  ISBN 0-9665337-0-4
             Full page color photograph of each species.

  "The genus Paphiopedilum--Natural History and Cultivation" - Part 2
    Dr. Guido Braem, Charles and Margaret Baker  ISBN 0-9665337-1-2
             Full page color photograph of each species.

     "Orchid Species Culture Vol. 3 - The Laelia/Cattleya Alliance"
                       coming in a few months.
__________________________________________________________________________