Dendrobium is a diverse genus of orchids with different cultural needs.
Many go through a growth phase and then a rest phase during the course of
one year, and must be given water and temperature to match these periods
of growth and rest. Flowers can last one day to many weeks, depending on
the type. Owing to the extreme diversity of the genus, we have categorized
culture according to the following main types:
Evergreen for several years, with thin, tall pseudobulbs, terminal inflorescences,
usually appearing in the autumn or twice a year (see culture). Species
such as Den. affine, Den. bigib-bum (phalaenopsis), Den. dicuphum and
Culture: Grow warm year round (see below); 60 F nights; water and
fertilize heavily when roots appear from new growth; medium light; reduce
water and fertilizer after growth finishes. If a short (three- to four-week),
cooler (55 F) dry rest is given, and then plants are warmed again (60
F minimum), another growth may mature during winter and flower in the
spring. Treat this growth as a summer growth cycle. These grow well with
phalaenopsis, except for the rest period. Plants will go deciduous if
grown too cool and dry.
Spatulata (Antelope Type)
Evergreen for several years. Most are large, vigorous plants with long-lasting
flowers in summer to several times a year. Species such as Den. antennatum,
Den. canaliculatum, Den. discolor, Den. gouldii, Den. johannis, Den. lineale
(veratrifoli-um), Den. stratiotes, Den. strebloceras and Den. taurinum.
Culture: Warm all year (60 to 65 F nights, 75 to 90 F days); no
rest period; can be kept cooler in winter if dry; medium to high light.
Most of the plants are pendulous, with leaves all along the canes that
most often drop with onset of cooler, drier weather. One to five flowers
per node are borne from the nodes of the leafless canes in mid-winter
through early spring.
Species such as Den. chrysanthum, Den. friedricksianum, Den. nobile and
Culture: Growth period in summer; give warmth, water and fertilize
heavily from when roots appear until top leaf appears on canes. Then give
high light, little or no water, no fertilizer, cool nights (40 to 50 F).
In other words, forget about them.
Species such as Den. anosmum (super-bum), Den. crassinode, Den. falconeri,
Den. fimbriatum, Den. findlayanum, Den. heterocarpum (aureum), Den. loddigesii,
Den. moniliforme, Den. parishii, Den. primulinus and Den. transparens.
Culture: Same as Group 1, but winter nights 55 F. Deciduous species
need virtually no water in winter.
Most are pseudobulbous plants with pendent inflorescences. Species such
as Den. aggregatum (now properly lindleyi), Den. chrysotoxum, Den. densiflorum,
Den. farmeri and Den. thyrsi-florum.
Culture: Summer - give warmth (60 to 90 F), medium light, medium
quantities of water and fertilizer. Winter - keep cool (50 F nights),
medium light, just enough water to keep pseudobulbs from shriveling, no
Leaves at top of pseudobulbs are large and leathery, inflorescence erect,
flowers commonly yellow-green. Species such as Den. atroviolaceum, Den.
macrophyllum and Den. spectabile.
Culture: Same as antelope types, but cooler and drier when resting
Formosae (Nigrohirsutae Type)
Canelike pseudobulbs, with black hairs on leaf sheaths and pseudobulbs
often apparent, leading to the popular name nigrohirsutae. Flowers usually
white, up to 4 inches across, two to three together from near the end
of the pseudobulb. Long lasting. Species such as Den. bellatulum, Den.
dearii, Den. draconis, Den. formosum, Den. infundibulum, Den. lowii, Den.
lyonii, Den. margaritaceum, Den. sanderae and Den. schuetzii.
Culture: Intermediate to cool year round, 50 to 60 F nights, maximum
85 F days. Water and fertilize when growing; give a slight short rest
(dry) when growth is completed. Keep barely moist until growth starts
Among the popular types are Den. linguiforme, Den. tetragonum, Den. gracillimum
and Den. cuthbertsonii (sophronitis).
Culture: Depends on the plant's native environment. It is generally
safe to grow them intermediate to warm (55 to 60 F at night), drying them
out in winter (or as growth stops). Hybrids between sections vary in culture.