CAMP LOT A NOISE TROPICALS

Cultural Information for PHAIUS

A genus of large, mostly terrestrial plants, Phaius is composed of some twenty species that produce tall spikes of showy flowers.

Phaius species inhabit tropical Asia, into China, Japan, Australia, and west to Africa and Madagascar. The most commonly cultivated is P. tankervilliae (syn. grandifolius), which has been in continual western cultivation since 1778, when the first plants were imported from China. P. tankervilliae is a deciduous, terrestrial orchid, which is more commonly known as the "Nun's Orchid" or the "Veiled Orchid".

Please realize these cultural instructions are general and should be adapted to the cultural environment in which they are to be applied..

GENERAL CONDITIONS

Phaius species should all be grown as terrestrial. In sub tropical areas, Phaius can be grown out of doors in flower bed situations. If grown in pots, Phaius should be grown in a well drained media, as they are intolerant of stale conditions at the roots.

TEMPERATURE AND LIGHT

Ideally. Phaius should be grown in the temperature range of 60 ° F. (16 ° Celsius) to 75 ° F. (24°Celsius) night to day. However, the plants will tolerate lower temperatures to 40 °F. (10 ° Celsius) or higher temperatures to 95 °F. (32 ° Celsius) on an occasional, short-term basis. Even so, these extremes can affect growth adversely and should be avoided if possible.

Phaius enjoy bright light to light shade. In subtropical areas, they can be grown in full sun year around. In other areas,Phaius can be adapted to full sun, if acclimated gradually, but must be protected from lower sustained temperatures.

WATER, POTTING MEDlUM, CONTAINERS

Since these are psuedobulbous plants, they have a facility for water storage, making this aspect of their culture very important. Avoid watering the foliage, but keep the medium moist by direct application of water to the pot. Phaius prefer to be evenly moist year around, except when the new growth has matured. At that time, Phaius prefers to dry out for approximately 3 to 4 weeks. Use of too much water or too frequent application of water may cause medium decomposition and subsequent root loss. Containers may vary from clay and plastic pots to wooden baskets. However, one must adjust watering schedules to suit the medium and container in use, also considering the conditions (humidity, light, temperature, air circulation) in which the plants are being grown.

If the roots are in reasonably good condition, Phaius respond rather quickly to adjustments in watering practices. For example, a plant which has become dehydrated (limp, wrinkled leaves) as a result of infrequent watering during warm, bright, and dry days will quickly pick up moisture when the plant is watered more frequently and/or placed in a more shaded, humid location.

Good air circulation is a necessity all year round. However, good air circulation is an absolute requirement when plants are in bloom to prevent spotting of the blooms by the fungus, botrytis. Botrytis is particularly common in cool and damp conditions. Good air circulation dries the plants and flowers, as well as keeps the spores of botrytis airborne. Always schedule watering early enough in the day to ensure that the plant, especially its leaf crown, is not left damp at night. Plants with damp crowns are susceptible to crown rots. Damp leaves are susceptible to leaf spotting fungal infections, which usually are not plant damaging just unsightly, until the leaf drops naturally in the fall.

Phaius are heavy feeders, therefore frequency of fertilizer application must be determined by considering temperature, light Intensity, and frequency of watering; all of these factors are inter-related. Generally applications made at 10-day intervals are effective with variations from 10-day to 20-day intervals suitable during certain times of the year.

The fertilizer formula should be compatible with the potting medium. Phaius are particularly fond of organic fertilizers, such as fish emulsion and manure teas. The organic fertilizers eliminate concern of salt build up in the medium. If using a salt based fertilizer, use a balanced ( ie, 20-20-20) for general growth and maintenance. Be alert to salt build up in the medium, which can damage the roots. Flush the medium often. The peat based combinations, such as ProMix®, often have supplemental fertilizer, so somewhat less fertilizer can be used with this medium. Whichever formula is selected, we recommend Better Grow Fertilizers at a rate of one level teaspoon per gallon at application.

TIPS

To control thrip on developing inflorescences or on mature flowers, use Orthene spray at rates recommended on the label. The chemical apparently does not damage the flowers or leave any unsightly residue.

Phaius leaves are soft and thin. As a result they can be easily bruised in careless handling. Be cautious not to damage foliage when moving the hose nozzle over and around plants during watering.

To prevent accumulation of moisture, overhead drip water, or condensation in the crown of the plant, it may be advisable to tip the plants slightly so the water will run out of the crown.

The thin leaves are sensitive to cold water. Since some water is splashed on the foliage at most every watering, damage can result when the water temperature is 10°F (5° Celsius) less than the ambient air temperature. They are also susceptible to sun burn, if grown very shaded and then moved to bright light. Phaius can tolerate, and enjoys, very bright light if introduced to the higher light intensity gradually.

Stake Phaius inflorescences as they develop, but do not move the plants during this development as the sprays may ultimately become crooked.

Repot only after flowering. Split clumps of pseudobulbs into small groups, of three or four pseudobulbs, to encourage flowering each year.

PROPAGATION

Phaius can be vegetatively propagated by cutting the flowering stem, into several pieces, above a stem internode, the dormant growth "eye" is covered with a triangular sheath. Cut, with a hot knife or shears, through the flower stem after the last flower has fallen. Dust the cuts with Rootone® . Place the cut stem pieces on damp sphagnum moss in diffused light. Pot the plantlets after the roots are several inches long.

**RECOMMENDED READING**

• All About Orchids, by Charles Marden Fitch
• Home Orchid Growing, by Rebecca Northen
• Orchids & How to Grow Them, by Gloria Jean Sessler
• Growing Orchids - Book Three, by J. N. Rentoul
• Encyclopedia of Cultivated Orchids, by Alex D. Hawkes
• Orchids for Everyone, by Brian Williams, et al.
• Illustrated Encyclopedia of Orchid Species, by Alec Pridgeon

CLAN Tropicals (Owned and Maintained by Orchids ' R ' Us, Inc.)