- Biên tập: Dũng Cá Xinh
- Người dịch: Huyền Nguyễn
ENGLISH
A well-grown spider orchid (Brassia gireoudi- ana) in full flower is an astonishing sight. The plant looks like it comes from outer space. The flowers are amazing, bizarre, fascinating. They’re huge, as much as 1 foot from top to bot- tom, with extremely skinny and spidery petals and sepals. They stand stiffly upright on each side of the flower stalk, lined up one behind the other in close formation, like a troupe of Cos- sack dancers with their arms and legs spread wide. The long-lasting, fragrant flowers are mostly green with large dark brown blotches and spots. Spider orchids are closely related to some other orchids frequently grown as house- plants such as dancing ladies, pansy orchids, and complex intergeneric hybrids like beallaras and alicearas. Hybridizers have been busy crossing them all, in every possible combination, to cre- ate new hybrid genera. Local supermarkets, big box stores, and independent garden centers all carry large numbers of these gorgeous orchids at very reasonable prices, and it is usually very easy to spot the influence of Brassia in the hybrids. The genes for large, spotted, spidery flowers are often transmitted to their offspring.
Spider orchids have one to three, 12- to 24-inch-long, 2.5-inch-wide, rather strap-like, leathery leaves borne atop smooth, glossy green pseudobulbs. The large, 6-inch-long pseudo- bulbs are really quite pretty, usually shaped like flattened teardrops, and function as water stor- age devices. They are clustered together at the soil line and produced at regular intervals from a creeping rhizome. Flower stalks generally erupt from their base. A new pseudobulb begins to grow about two to four weeks after the last flow- ers have faded.
Many people find that their spider orchid grows well vegetatively, but fails to flower.
Growers call this a blind growth. You can avoid blind growths in your spider orchids by paying close attention to their needs for light, water, fertilizer, and temperature when the rhizome begins to make a new pseudobulb. Look for new green roots with white tips emerging from the base of the pseudobulb that has just finished flowering. The pointed end of a new growing point begins to show at the same time as the new roots. When you see this new growth of roots and foliage be diligent about meeting your plant’s cultural needs. That new growth you spotted slowly matures into a new pseudobulb, which eventually flowers.
OPTIMUM HOUSEHOLD ENVIRONMENT
Read the Introduction for the specifics of each recommendation.
MEDIUM LIGHT.
Bright filtered light from an east window is ideal for spider orchids. No direct sun. And avoid the heat load of a south or west window.
LOW TEMPERATURE.
Daytime 65 to 75°F, night- time 60 to 65°F.
LOW WATER.
Give these orchids a good long drink once a week. Orchids are sensitive to water qual- ity and should be irrigated with filtered, rain-, or distilled water, rather than tap water. Let tepid water flow through the entire root zone until all the potting medium is soaked. Let the pot drain and air out, then put it back in its place. Mark the pot so that your plant is returned to its orig- inal position every time. Turning your orchid causes the flowers to twist and bend to face the light, which destroys their elegant arrangement.
HUMIDITY.
Mist your plant several times a week with a spray bottle of water on a mist setting, or use a handheld mister. Put the pot in a saucer or tray of water, but make absolutely sure the bot- tom of the pot never sits directly in the water by raising the pot up on pot feet or pebbles. Consider putting a humidifier in the room.
POTTING MEDIUM.
Use any good organic, orchid potting medium such as medium orchid bark. Do not use garden soil or ordinary potting soil because it will kill this epiphytic orchid.
FERTILIZER.
Use any balanced organic fertilizer, in either a water soluble or liquid formulation, to promote good growth and flowering. Apply at one-quarter-strength at least once a week right after you water your orchid.
POTTING.
Your spider orchid needs to be up- potted every two years or so. Choose a pot with a diameter 2 inches larger than the current pot. Orchids generally prefer being rootbound in smallish pots. Re-pot after flowering is com- plete and when new growth and new roots start to emerge. Spider orchid roots are small, slen- der, and easily damaged, so treat them gently. Be attentive to watering after up-potting or re- potting these plants and do not allow them to dry out.
PROPAGATION.
Spider orchids are easy to propa- gate by division of the rhizome. Next time you need to up-pot your plant cut the rhizome into two pieces so that each piece has a decent num- ber of roots, pseudobulbs, and leaves.
COMMON PROBLEMS
Watch for sunburn (page 256), mealybugs (page 262), and root rot (page 272).