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Growing the Best PhalaenopsisText by Erik Runkle, PhD, Yin-Tung Wang, PhD, Matthew Blanchard and Roberto Lopez

Part 1: An Introduction to Potted Phalaenopsis Orchids

FLOWERING ORCHIDS HAVE BE-come one of the most popular andtrendy potted plants to purchase inmany countries throughout the world.Orchids seem to be everywhere — ontelevision, in home and gardenmagazines and at your local massmerchandiser. Why? As readers ofOrchids magazine, most of you alreadyrealize the many positive attributesabout potted flowering orchids.Phalaenopsis, or the moth orchid, hasflowers that can last for months, and isrelatively easy to care for and reflowerin the home. In addition, commercialproduction has become more efficientand thus production costs havegone down, making phalaenopsis anaffordable plant for orchid hobbyists,connoisseurs and amateurs alike.

Phalaenopsis plants have beengrown and enjoyed for many decades.Once prized primarily by orchidhobbyists, they were expensive topurchase and not usually availableoutside of specialty shops or orchidvenues. Over the past 20 years,production information generated bygrowers and researchers has advancedto the point that phalaenopsis can bescheduled to flower in mass quantitiesthroughout the year, especially forsales at holidays. In addition,hybridization by breeders has led toorchids with more desirable traits,flower colors and flower sizes. This hasopened the door for more consumersto enjoy orchids and perhaps catchorchid fever.

This article is the first of a four-partseries that focuses on the cultivationof phalaenopsis. The series containsresearch-based information, much ofwhich has been generated at MichiganState University and Texas A&MUniversity. There are still many mythson how to grow orchids, but this is ourattempt to set the record straight. Thisseries of art icles was originallypublished in Greenhouse Growermagazine, and has been modified fororchid enthusiasts with a wide rangeof growing experiences.

This first art icle provides in -t roduc tory in format ion on pha-

TOP Three phalaenopsis plants are put in

a decorative container in Japan. Wired

flower spikes create a showy floral display.

ABOVE A grouping of miniature multiflora

phalaenopsis. Grower: Sogo Team Co.

OPPOSITE Phalaenopsis are capturing the

high-end retail market, where they can be

purchased in decorative containers with

attractive packaging. These plants were

being sold in England.

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laenopsis and options for startingmaterial and propagation. The secondand third articles will focus on cul-tural and environmental methods forvegetative growth and flowering ofphalaenopsis. The series will culmi-nate with an example of a detailedphalaenopsis production schedule.

RISE IN POPULARITY Floweringorchids have become the second-mostvaluable potted flowering plantproduced in the United States. In 2005,the wholesale value of potted orchidssold in the United States was estimatedat $144 million by the USDA. However,this statistic includes only commercialgreenhouses that have sales of at least$100,000 per year. Therefore, the orchidindustry is much larger than the USDAstatistics indicate.

Phalaenopsis are not just popularin North America; for the past severalyears, they have been the mostvaluable potted plant sold at the Dutchflower auctions. They are also highlyprized gifts throughout Asia, especiallyin Japan. The presentation of the giftis important, and thus great care istaken to ensure a stunning flowerdisplay. Luxury orchids are also makingtheirway into Europe and the UnitedStates, where orchids are displayed indecorative containers and high-endpackaging.

Phalaenopsis are produced through-out the world, most notably in Germany,Japan, the Netherlands, Taiwan,Thailand and the United States. Manyyoung plants are propagated by tissueculture in the Netherlands, Taiwanand Thailand, and then are exportedto other countries (including theUnited States) for subsequent growthand flowering. There are hundreds,if not thousands, of phalaenopsishybrids and clones available forpurchase. Orchid propagators havebeen intensively breeding pha-laenopsis for desirable flowering andplant characteristics including specificflower colors and color patterns, multi-and branched flower spikes, and mostrecently, fragrance.

Breeding continues at a rapid pace,mainly in Taiwan, and a popular cultivar

available today may not becommercially available in just a fewyears. Flower colors include white,yellow, green, apricot, pink, magentaand dark maroon. Flowers can be of onecolor or two, with different-coloredcenters or margins or with variouspatterns including spots and stripes.The newest harlequin flowers, white oryellow with irregular purple blotches,can command a premium price.

PROPAGATION Although somephalaenopsis are produced from seed,an increasing majority are cloned froma growing point, or meristem. Theseplants are called “mericlones.” Thecloning process reduces variabilityfrom plant to plant, so that populationshave similar growth and floweringcharacteristics. The cloning processalso helps ensure consistent flowercolors and patterns, whereas plantsraised from seeds are more variable.

Phalaenopsis are propagated inlaboratories by tissue culture, and areusually grown in sealed flasks for 10 to12 months under low light. However,many propagators now place theseflasks in greenhouses having much

higher light than in the laboratory.When young plants reach a leaf spanof about 2 inches (5 cm) or larger, theyare ready to be taken out of the flasksand be transplanted. Many plants areshipped while still in flasks because itis relatively easy to ship flasks, andbecause of restrictions with importingplants growing in a bark- or sphagnum-based media.

Once plants are removed from theirflasks, they are grown for approximately20 to 30 weeks at 80 to 90 F (27 to 32 C)until they are ready for transplanting intoa larger finish container. If plants aregrown at cooler temperatures, theydevelop more slowly. In addition, overtime, some young plants may begin toform a small flower spike. Becausevegetative growth is promoted by hightemperature, many plants are grownuntil maturity in tropical and subtropicalenvironments (such as Florida andsouthern California). During this periodof t ime, plants are grown undermaximum light intensities of about 1,500foot-candles. Young plants grownunder higher light intensities generallyhave shorter but thicker leaves.

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Plant size, or maturity, is oftenexpressed as the leafspan from one endof a leaf to the opposite leaf end. Asyoung plants develop, each new leafbecomes larger than the previous one.Subsequent growth continues at thesehigh temperatures to inhibit floweringand promote rapid leaf development.After transplanting to a largercontainer, plants may need another 20to 25 weeks before they are capable ofspiking. Plants must be large enough,or mature, before they can flower.Although differences exist amongcultivars, many won’t flower uniformlyuntil the leafspan of a populationaverages at least 10 inches (25 cm)wide. Breeders are developing morehybrids and clones that mature whenreaching a smaller (15-cm) leaf span, butthe actual number of leaves required

to reach maturity may be similar to thelarger hybrids.

Several different sizes of plants canbe purchased, including plants inflasks, immature plants that are not offlowering size, and large, mature plantswithout or with flower spikes. Thelarger the plants, the higher the price.Phalaenopsis plants growing in mediacan be purchased from companieswithin the United States. Alternatively,bare-root plants (without media)can be imported, usually from theNetherlands, Taiwan or Thailand.Commercial growers now can importphalaenopsis in an approved growingmedium from Taiwan, made possiblefrom a recent ruling by the UnitedStates Department of Agriculture,Animal, and Plant Health InspectionService (USDA APHIS).

The international transportation oforchids is strictly controlled by aninternational treaty, and therefore, adomestic grower must secure theproper permits before ordering from aforeign supplier. A General Permit ($70for two years) and a Plant Import Permit(free) are required. These permits canbe obtained from the USDA. Also, makesure the supplier includes a copy ofthe Convention on International Tradein Endangered Species of Wild Faunaand Flora (CITES) documentation withthe shipment. CITES regulations havebeen changed in the recent past to allowfor importing phalaenopsis hybridsand clones without accompanyingCITES documentation under certainconditions. The CITES document isissued by the government of theexporting country to indicate that the

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OPPOSITE Phalaenopsis, propagated by

tissue culture, are grown in flasks for 12 to

18 months before first transplanting.

ABOVE A harlequin-type phalaenopsis:

Phalaenopsis Diamond Beauty ‘Taida #1’

(Haur Jin Diamond × Chingruey’s Beauty).

Grower: Taida Orchids.

LEFT Approximately 20 to 25 weeks after

the first transplant, phalaenopsis are

transplanted into a larger pot [here, in a

4-inch (10-cm) pot] for continued

vegetative growth or are sold as bare-root

young plants.

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orchid plants being shipped areartificially propagated and were notillegally removed from the wild. Allimported orchids are inspected byAPHIS officers at a port of entry beforebeing released to a customs broker iffound free of pests. Because of theseregulations, most imported orchids arebrought into the United States bycommercial orchid growers.

In general, the larger the plant atthe beginning of forcing, the moreflower buds and flower spikes(inflorescences) it will have. Althoughsome phalaenopsis hybrids or cloneswill flower with less than a 10-inch (25-cm) leafspan, usually the flower spikeis short and has a low bud count. Inthe Netherlands, two flower spikes perplant are common, yet in the UnitedStates, many plants are sold with onlyone spike. However, more and moreplants are being sold in the UnitedStates with multiple flower spikes.

A hobbyist interested in producinga showy phalaenopsis, such as for anorchid show, could purchase youngplants that have never flowered andgrow them for many months at a hightemperature (above 82 F, or 28 C).Assuming adequate plant culture,leaves will continue to develop, yetflowering will be inhibited. As plantsproduce more leaves, they develop theability to produce more and largerflower spikes.

In next month’s issue of Orchids,the second article in this series willfocus on how growers successfullymanage the root zone (media, fertilityand watering) of phalaenopsis.

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Erik Runkle, PhD, is an assistantprofessor and floriculture extensionspecialist at Michigan State University.He was recently elected vice chair of theInternational Society for HorticulturalScience Orchid Working Group.Department of Horticulture, A240-CPlant and Soil Science Building, EastLansing, Michigan 48824 (e-mailrunkleer@msu.edu). Yin-Tung Wang,PhD, is professor of floriculture at TexasA&M University. (e-mail yt-wang@tamu.edu). Matthew Blanchard andRoberto “RoLo” Lopez are PhDgraduate assistants at Michigan StateUniversity. They would like to thank theFred C. Gloeckner Foundation, theAmerican Orchid Society, Taiwan SugarCorporation, Project GREEEN, andprivate greenhouse companies thatsupport orchid research.

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OPPOSITE TOP Phalaenopsis plants that

bloom at a leafspan of less than 6 inches

(15 cm). Grower: Sogo Team Co.

OPPOSITE MIDDLE An example of

commercial phalaenopsis production in

the Netherlands. Note that most plants

have at least two flower spikes.

OPPOSITE BELOW Mature, vegetative

phalaenopsis grown in Taiwan are of

sufficient size to flower.

THIS PAGE Phalaenopsis Brother Orange

Runabout (Timothy Christopher × Brother

Sara Gold).