64 July 2005 • Greenhouse Grower

by ERIK RUNKLE, YIN-TUNG WANG,MATTHEW BLANCHARD and

ROBERTO LOPEZ

ORCHIDS, orchids, theyseem to be popping upeverywhere. They’re ontelevision, in home and

garden magazines and at your localmass merchandiser. And they’re notjust for the rich and famous anymore.They are now one of the hottest pottedflowering plants to purchase.

Why? There are many positive attrib-utes to potted flowering orchids. Forone, they are tropical plants that arestill considered unique, stylish and ex-otic. Phalaenopsis, or the moth orchid,has flowers that can last for months,and they are relatively easy to care forand reflower in the home. And, be-cause commercial production has be-come more efficient, costs have gonedown, making them an affordable al-ternative to other flowering crops.

Phalaenopsis orchids are nothingnew – they have been grown and en-joyed for decades. Once prized pri-marily by orchid hobbyists, they wereexpensive to purchase and not usuallyavailable outside of specialty shops ororchid venues. Over the past 20 years,production information generated bygrowers and researchers has advancedto the point that phalaenopsis can bescheduled in flower en masse for spe-cific markets. In addition, hybridiza-tion by breeders has led to orchidswith more desirable traits.

This article is the first of a four-partseries that focuses on commercial pro-duction of flowering phalaenopsis or-

chids. Unlike some production guides,this series of articles contains research-based information, much of which hasbeen generated at Michigan StateUniversity and Texas A&M University.There are still many “wives tales” onhow to grow orchids, but this is ourattempt to set the record straight.

This article provides introductoryinformation on phalaenopsis and op-tions for starting material and propa-gation. The second and third articleswill focus on cultural and environ-mental methods for vegetative growthand flowering of phalaenopsis plants.The series will culminate with an ex-ample of a detailed phalaenopsis pro-duction schedule.

A Hot CropIt might surprise you that potted

flowering orchids are the second-mostvaluable potted flowering plant pro-duced in the United States. In 2004, thewholesale value sold in the UnitedStates was estimated at $127 million bythe USDA. About 80 percent of thisvalue was for phalaenopsis. California,Florida and Hawaii produce more than85 percent of all the orchids sold in theUnited States, with wholesale valuesreported at $48 million, $40 million and$17 million, respectively.

Phalaenopsis dominate the orchidmarket because of their long-lastingflowers, wide range of flower colors,ease of care and ease to schedule intoflower. Additionally, flowering pha-laenopsis command a considerablyhigher wholesale price when comparedto more traditional potted plants.

Phalaenopsis are not just popular inNorth America; for the past few years,they have been the most valuable pot-ted plants sold at the Dutch flower auc-tions. They are also highly prized giftsthroughout Asia, especially in Japan.

An International MarketplacePhalaenopsis are produced through-

out the world, but most notably inGermany, Japan, the Netherlands,Taiwan, Thailand and the UnitedStates. Outside of the United States,many young plants are propagatedand grown in the Netherlands, Taiwanand Thailand.

Similar to poinsettia, greenhousegrowers obtain orchid genetics fromcompanies that have been intensivelybreeding for desirable flowering andplant characteristics. Many companiesare breeding for specific flower colors

P R O D U C T I O NO R C H I D S

Orchids are the second hottest potted flowering plant in the United States. Find

out how to cash in on the exotic crop everyone wants in this four-part series.

The OrchidGrower

Three flowering orchid plants are puttogether in a decorative container inJapan. Flower spikes are wired to cre-ate a very showy floral display.

65 July 2005 • Greenhouse Grower

and color patterns, multi- and single-branched flower spikes, and most re-cently, fragrance. Some of the largerbreeding companies and young plantproducers are Altria, Floricultura,Formosa, I-Shin, Taiwan Sugar,Twyford and Yupin. Growers shouldconsider evaluating the genetics fromseveral sources to determine how cul-tivars perform and which best suittheir market.

Plant MaterialThere are literally hundreds, if not

thousands, of phalaenopsis hybridsand clones available for purchase.Breeding continues at a rapid pace,and a popular cultivar availabletoday may not be commercially avail-able in just a few years. Flower colorsinclude white, yellow, green, apricot,pink, magenta and dark maroon.Flowers can be of one color or two,with different colored centers or mar-gins or with various patterns includ-ing spots and stripes. The newest har-lequin flowers are white with irregu-lar purple blotches.

Although some phalaenopsis areproduced from seed, an increasingmajority are cloned from a growingpoint, or meristem. These plants arecalled “mericlones.” The cloningprocess reduces variability from plantto plant, so populations have similargrowth and flowering characteristics.

Phalaenopsis are propagated in lab-oratories by tissue culture, and areusually grown in flasks for 10 to 12months under low light (maximum of50 to 100 footcandles, or 10 to 20µmol•m-2•s-1) (Figure 3). When youngplants reach a leaf span of about 2inches (5 cm), they are taken out ofthe flasks and transplanted into flatsor small pots containing a fine bark-or sphagnum-based media.

Once plants are removed fromtheir flasks, they are grown for 20 to25 weeks at 80°F to 90°F, (27°C to32°C) until they are ready for trans-planting into a larger container.Vegetative growth is promoted by

P R O D U C T I O N

O R C H I D S

Left: Phalaenopsis propagated by tissue culture in Thailand. Plants are grown inflasks for 10 to 12 months before first transplanting.Right: After removal from the flask, plants are grown at 80°F to 90°F (27°C to32°C) in either flats or small containers.

For Details Circle No. 53 on Postcard or at www.greenhousegrower.com

66 July 2005 • Greenhouse Grower

high temperature (80°F to 90°F), andthus most plants are grown until ma-turity in tropical and subtropical en-vironments. Plant size, or maturity, isoften expressed as the leaf span fromone end of a leaf to the opposite leafend. As young plants develop, eachnew leaf becomes larger than the pre-vious one. After transplanting to alarger container, plants may need an-other 20 to 25 weeks before being capable of spiking.

Subsequent growth continues atthese high temperatures to inhibit flow-ering and promote rapid leaf develop-ment. Plants must be large enough, ormature, before they are capable of flow-ering. Although differences existamong cultivars, most cultivars won’tflower uniformly until the leaf span of apopulation averages at least 10 inches(25 cm) wide. However, breeders aredeveloping more hybrids and clonesthat mature when reaching a smaller

(15 cm) leaf span.There are several different sizes of

plant material that can be purchased,including plants in flasks, immatureplants that are not of flowering sizeand large, mature plants without orwith flower spikes. The larger theplants are, the higher the price.Phalaenopsis plants growing in mediacan be purchased from companieswithin the United States.Alternatively, plants can be importedas bare-root, often from theNetherlands, Taiwan and Thailand.Growers now can import phalaenop-sis in an approved growing mediafrom Taiwan, made possible from a re-cent ruling by USDA’s Animal andPlant Health Inspection Service(APHIS). When purchasing pha-laenopsis from offshore sources, askfor the C&F price, which includes thecost for the plants and freight.

Measuring UpThe size of plant material purchased

determines if and how long plantsneed to be grown at high temperature

P R O D U C T I O NO R C H I D S

For Details Circle No. 17 on Postcard or at www.greenhousegrower.com

Approximately 20 to 25 weeks afterthe first transplant, phalaenopsis aretransplanted into a larger pot [here, ina 4-inch (10 cm) pot] for continuedvegetative growth, or are sold as bare-root young plants.

67 July 2005 • Greenhouse Grower

for additional vegetative growth. Ingeneral, the larger the plant at the be-ginning of forcing, the more flowerbuds and flower spikes (inflores-cences) it will have. Although someplants will flower with less than a 10-inch (30-cm) leaf span, usually theflower spike is short with low budcount and is unacceptable to the mar-ket. In the Netherlands, two flowerspikes are common per plant, yet inthe United States, many plants aresold with only one spike. Plants withmultiple spikes usually command ahigher price, making the purchase oflarger plants for forcing sometimes acost-effective strategy.

Since transporting orchids of anykind internationally is strictly con-trolled by an international treaty, a do-mestic grower must secure the properpermits before ordering from a foreignsupplier. A General Permit ($70 fortwo years) and a Plant Import Permit(free) are required. These permits may

be obtained from theUSDA. Also, make surethe supplier includes acopy of CITES documenta-tion with the shipment.The CITES document is is-sued by the government ofthe exporting country toindicate that the orchidplants being shipped areartificially propagated. Allimported orchids are in-spected by APHIS officersat a port of entry beforebeing released to a cus-toms broker if found freeof pests.

Look for next month’sarticle in GreenhouseGrower for the second ar-ticle on production ofphalaenopsis. It willfocus on managing the root zone(media, fertility and watering) andlighting guidelines. GG

About the authors: Erik Runkle is assistantprofessor and floriculture extension spe-cialist, and Matthew Blanchard and

Roberto “RoLo” Lopez are graduate assis-tants at Michigan State University. Yin-Tung Wang is professor of floriculture atTexas A&M University. The authors would like to thank the FredC. Gloeckner Foundation, the AmericanOrchid Society, Project GREEEN and pri-vate greenhouse companies that supportorchid research.

P R O D U C T I O NO R C H I D S

Mature, vegetative phalaenopsis grown in Taiwanare of sufficient size to flower.