Culture of Dendrobium Nobile Hybrids
Dendrobium nobile hybrids are popular for their show of bright colored flowers along the stems in late winter and early spring. They are easy to grow, but they have a couple of unique cultural requirements.
When the new growth begins in the spring, these Dendrobiums like to have an increase in water and fertilizer. Culture during spring and summer is similar to Phalaenopsis, with reduced light, increased water, and fertilizer every two weeks (1tsp. per gal. of water soluble fertilizer).
In the fall, cultural needs change drastically. Bright light, cooler temperatures, and no fertilizer will help to initiate flower bulbs. Water normally so that the bulbs do not shrivel. Buds will appear when the night temperatures are cooler and the growths have fully matured. This is usually in mid-winter, with blooms opening in January and February.
When these plants are grown in the home, we recommend that they be placed outside in the fall to benefit from the cooler temperatures at night and brought inside just before the onset of freezing weather. They then need to be put into a relatively cool location (such as an unheated room or an enclosed porch) until the buds starts to form.
Do not over pot the plants. They like to be root-bound and do well in relatively small pots. Clay pots suit them well, as does regular seedling bark mixture or osmunda. Some growers also use long-fiber sphagnum moss for these Dendrobiums.
Keikis or off shoots may form on the stems. And these may be potted as new plants when they start to form roots. If plants produce all keikis and no blooms, too much fertilizer has been given or the temperature has been too warm at night, one of these is usually to blame.
Callista Most are bulbous plants with a pendent inflorescence.
Species: Aggregatum, Chrysotoxum, Densiflorum, Farmeri, Thyrsiflorum, etc.
Culture: In summer give warmth (60° 90°), medium light and medium quantities of water and fertilizer. In winder give cool (50° nights), medium light, and just enough water to keep bulbs from shriveling, no fertilizer.
Spatulata (Antelope type) Evergreen for several years. Most are large, vigorous plants with long-lasting blooms in summer to several times a year.
Species: Antennatum, Canaliculatum, discolor Gouldii, Johannis, Lineale (Veratrifolium), Stratiotes, Strebloceras, Taurinum.S
Culture: Warm all year (55° 60° nights, 65° 90° days); no rest period; can be kept cooler in winter if dry; medium to high light.
Dendrobium Most plants pendulous, leaves all along canes. Flowers 2 5 per inflorescence, from upper nodes of leafless canes.
Species: Group 1 Chrysanthemum, Friedricksianum, Nobile, Wardianum. Group 2 Anosmum, Crassinode, Falconeri, Fimbriatum, Finlayanum, Heterocarpum (Aureum), Loddigesii, Parishii, Primulinum, Transparens.
Culture: Group 1 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 to no water, no fertilizer, cool nights (40° 50°). In other words, forget about them! Group 2 same as Group 1, but winter nights 55°. Deciduous species need virtually no water in winter.
Latourea Leaves at top of pseudobulbs are large and leathery, inflorescence erect, flowers commonly yellow green.
Species: Atroviolaceum, Macrophyllum, Spectabile, etc.
Culture: Same as Antelope-types, but cooler and drier when resting in winter.
Formosae Cane-like pseudobulbs, with black hairs on leaf sheathe and pseudobulbs often apparent. Flowers usually white, up to 4 across, 2 to 3 together from near the end of the pseudobulb.
Species: Bellatulum, Dearii, Draconis, Formosum, Infundibulum, Lowii, Lyonii, Margaritaceum, Sanderae, Schuetzii.
Culture: Intermediate to cool year round, 50° 60° nights, and max 85° days. Water and fertilize when growing, give a slight short rest (dry) when growth is complete and keep barely moist until growth starts again.
Phalaenanthe Evergreen for several years, with thin, tall pseudobulbs, terminal inflorescences, usually appears in a ball or twice a year.
Species: Affine, Bigibbum, Dicuphum, Palaenopisis, Williamsianum.
Culture: Grow warm year around; 60° nights; water and fertilize heavily when roots appear from new growth; low to medium light; reduce water and fertilizer after growth finishes. If a short (3 4 week), cooler (55°), dry rest is given, and then plants are warmed again (60° min), another may mature during winter and bloom in spring. Treat this growth as a summer growth cycle. These grow well with Phalaenopsis, except for the rest period. If you must keep plants cool in winter, keep them bone dry until the weather has begun to warm, then water as growth appears. Plants will go deciduous with this cool/dry treatment.
Other Species Linguiforme, Tetragonum, Gracillimum, Cuthbertsonii (Sophronites).
Culture: Depends on the plants native environment-try to find out. It is generally safe to grow them intermediate to warm (55° 60° night), drying them out in winter (or as growth stops). Hybrids between sections vary in culture.