340 ORCHIDS MAY 2006 WWW.AOS.ORG

ORCHID PORTRAIT

Vegetative Propagation By Charles Marden Fitch

Multiply Your Favorite Orchids

INCREASING ORCHID PLANTS ISpart of orchid-growing pleasure. Thereis a saying, “The best way to keep aplant is to give it away.” Horticulturally,that means to give away a propagationor division. By sharing your favoriteorchids with other growers you areproviding the clone with an insurancepolicy. Should some misfortune befallyour plant, you have a good chance ofgetting a return propagation from thegifted division’s thriving in anothercollection. This is of major importancefor select clones that have not beenpropagated by tissue culture.

WHAT CAN HAPPEN A commoncalamity in temperate regions is deathby freezing. When winter weatherbrings heavy snow, ice, power failuresand wind storms, a whole collection oforchids risks dying when temperaturesfall below 32 F (0 C). Some genera willbe badly damaged by cold even beforewater freezes. In warmer areas, the risksinvolve sunburn if shade material blowsaway, heat damage if automated ventsfail to open in hot weather and violentstorms that fell trees and dismantlebuildings or even a strong hurricane.

If you lose orchid clones that are

already widely distributed from tissueculture or many years of division, as inthe case of Paphiopedilum, you havea good chance of replacing favoriteplants from commercial sources.

REASONS Besides the peace ofmind in having a special clone growingin several collections, consider otherreasons to propagate your superiororchids:

◆ Orchids to donate for localorchid society sales, auctions andraffles.

◆ Grow more of your favoriteclones, perhaps to increase flowerproduction.

◆ Test divisions of the same cloneunder varied cultural conditions. Forexample, to try different fertilizers,potting mixtures, container types, lightexposure or temperature variations.

◆ Raise plants to sell. Extra moneyis handy when you are reading newcatalogs or visiting an orchid show.

◆ Give plants to people newlyexpressing an interest in horticul-ture. I t is especially rewarding toencourage young people beginning togrow orchids. Some outlets includeschools where individual teachersare enthusiastic about plants in theclassroom.

CANDIDATES When decidingwhich orchids to propagate, begin withyour favorite clones. In my collection,I give priority to clones that doespecially well under conditions that Ican easily offer. You might enjoypropagating an orchid that won youan award or one that everyone ad-mires when visiting your collection.Rare species are good candidatesfor vegetative propagation at home.Commercial growers needing thousandsof plants will use meristem tissue culture(an efficient asexual method ofvegetative propagation). If you wantto have an orchid propagated by tissueculture, it is easy to have this done at acommercial orchid lab. I sometimes sendstems of favorite Phalaenopsis hybridsto a lab for stem propagation. Havingseveral plants of my favorite clonesprovides extra flowers to give awayplus backup plants for testing orreplacement when an individual diesfrom rot.

DIVISION Dividing multiplegrowth plants is the popular way topropagate many orchids. Genera that areeasy to divide include Cattleya,Oncidium, Brassia, Epidendrum, Cym-bidium and Paphiopedilum, among themost popular. Hybrids based on thesegenera are also multiple-growth orchids,botanically called sympodial.

Iris, the common garden plant, isan easy to understand sympodial plant,growing much like a Cattleya from acreeping rhizome having buds alongthe sides that sprout to make newgrowths (called leads by orchidgrowers). Not all of the live buds on arhizome grow at the same time.Typically, several buds remain dormantunless the prominent growing lead(new growth) is damaged.

USEFUL INJURY You can inducethe dormant buds to sprout, especiallyin orchids with easy-to-reach above-ground rhizomes, by causing injury tothe rhizome. Choose a point two orthree growths (pseudobulbs) behind anactive lead on a healthy establishedplant. With a sharp sterile knife or othersterile cutt ing tool, cut halfwaythrough the rhizome. Dust the cut witha fungicide powder such as Rootone.These horticultural powders havehormones to stimulate cuttings butthey also contain a fungicide thatreduces problems of rot. Dormant budsbehind the cut frequently sprout,developing a new active leads. Thisuseful injury is best done at least oneseason before you plan to repot theorchid. At repotting time you willalready have at least two active clumps.

NATURAL CLUMPING A vig-orous sympodial orchid grown well willform a multiple-lead plant in a fewyears. Some vigorous hybrids, bothseed grown and tissue cultured, form

LEFT Dendrobium Friendship ‘Champion’

(Utopia × Ruby Blossom), a nobile-type

Dendrobium, forms keikis on mature

growths that can be removed and potted

to make new plants.

OPPOSITE Ascocentrum ampullaceum

‘Lauray’, CCM/AOS, can be propagated

from plantlets or offsets that grow near the

base of the main plant. Grower: Judith

Becker.

WWW.AOS.ORG MAY 2006 ORCHIDS 341

PH

OT

OG

RA

PH

S B

Y C

HA

RL

ES

MA

RD

EN

FIT

CH

342 ORCHIDS MAY 2006 WWW.AOS.ORG

multi-lead clumps even before flowering.This natural clumping is common withcymbidiums, paphiopedilums, brassias,and oncidiums. Vegetative propagationby dividing multiple-lead plants is easyto do at repotting time.

SEASONAL SELECTION Thebest time to divide orchids is when theyare actively growing. Seasonal vari-ations occur around the world andwithin genera so it is best to remembera horticultural basic: Divide plantswhen they will have several months ofgood growing conditions to establish.For growers in temperate regions, thismeans spring and early summer, whenorchids often are making new growth.With several months of warm brightweather ahead, the divisions made fromspring into early summer have anoptimum opportunity to establishbefore winter brings lowered light andperhaps cooler conditions.

Orchids divided when they areunder stress or not active (resting) aremore likely to suffer. Providing gentlebottom heat and humidity above 60percent will help recently dividedplants establish. In my greenhouse, Iput such plants on a bench where heatwarms the plants from below. A tray ofwater is under the pots. Usingfluorescent lamps is another useful wayto help orchids establish. Thefluorescent l ight provides goodillumination without the risk of sunburnor cloudy winter days.

USING BACKBULBS Divideclumping multiple-growth orchids,such as cymbidiums, into divisions ofat least one active new growth andthree or four live healthy backbulbs.Some of the cut-away backbulbs, theoldest of the clump, will still have live“eyes.” Study the cut-off pseudobulbsfor live dormant buds. Sometimes it isnot easy to know whether a rhizome orback bulb has viable bud. You mightas well take a chance that the cut-awaysection will sprout if you want topropagate a divided clone. Toencourage older cut-off growths tosprout, dust the cuts with Rootone orsimilar hormone-fungicide powder.Place the divisions on moist coarsesphagnum moss in a tray or pot. Keepthe back divisions in a shady moistplace. In a few months, any live buds(eyes) should sprout and begin makingroots. Once you see a division is active,pot it in a relatively small container.You may find that old orchid growthsthrown on a compost heap during early

ORCHID PORTRAIT

PH

OT

OG

RA

PH

S B

Y C

HA

RL

ES

MA

RD

EN

FIT

CH

WWW.AOS.ORG MAY 2006 ORCHIDS 343

summer repotting sprout into sturdyplants over the summer without anycare from you. These vigorous orchidsare fun to see but if you decide to savethem be sure that they are pest-free. Irecommend that you leave the trulydiscarded parts in the compost whereyou threw them early in the season.Having correct names and a healthyclean growing environment are betterfor choice divisions.

CUTTING TOOLS Use sharpsterile cutting tools to divide yourorchids. Virus is dangerous for orchidsbecause it often causes malformed andblotched flowers. Vigorous plants maynot show blotched foliage or virus-spotted flowers, so it is important tosterilize cutting tools after each plant.I use flame from an alcohol burner orgas stove. Steam and boiling water arealso useful sterilizing techniques, butmore practical in a lab setting than in ahome collection. Choose cutting toolsthat can endure the flame sterilization.I like stainless steel pruning tools fortough rhizomes. Sometimes a big clumpof Cymbidium must be divided with asaw. A commercial grower I talked withsaid he uses a small handheld electricsaw to divide his cattleya hybrids.Many of the older popular orchidsbecame infected with various virusesat commercial collections beforeknowledge of viruses was common.Even now, one may occasionallyencounter infected orchids in thecommercial circle. Keep your orchidshealthy by using sterilized cutting tools.

Repotting terrestrial orchids suchas Paphiopedilum may require a trowelfor potting mix plus a cutting tool to dodividing. A useful new tool made inChina is called a Multi-Use Transplanter.I use the Oxo stainless steel transplanterthat incorporates a strong straight edgewith teeth (serrations) on the oppositeside. The 41/2 inch (11.25 cm) blade isstrong enough to pry plants out ofpots, while the sharp thin tip is goodfor scraping off tight roots. This cleverlittle tool sells for about $5.

For tougher dividing jobs, choosea pair of sturdy pruning shears. Goodbrands with several choices from eachcompany include Fiskars (famous forprecision scissors), Oxo “Good Grips”hand shears and Wilkinson (made inthe United Kingdom). When you use aflame to sterilize these tools, avoidgetting fire near the plastic or paintedhandle sections.

MONOPODIAL GENERA You can

OPPOSITE TOP LEFT One way to multiply

Oncidium Gower Ramsey (Goldiana ×

Guinea Gold) is to pot backbulbs, water

and wait for new growths, at which time the

backbulbs can be potted individually.

OPPOSITE TOP RIGHT Aliceara Mervyn

Grant ‘Talisman Cove’ (Miltassia Star

Fighter × Oncidium crispum) is an example

of a tissue-cultured plant.

OPPOSITE Among orchids that can be

divided is Epidendrum radicans, including

this specimen that was just potted with

coconut fiber, gravel and charcoal.

TOP LEFT Plantlets (keikis) are seen more

often on dendrobiums and phalaenopsis,

but cattleyas can also produce them. Here,

a plantlet is high up on the pseudobulb.

TOP RIGHT Colmanara Jungle Cat

‘Talisman Cove’ (Jungle Monarch

‘Everglades × Rhynchostyle [syn.

Odontoglossum] bictoniensis) is a good

choice for vegetative propagation by

division or tissue culture .

ABOVE Backbulbs of Cymbidium Madrid

‘Forest King’, HCC/AOS (Vale of Kashmir ×

Peri) three months after cutting.

344 ORCHIDS MAY 2006 WWW.AOS.ORG

PH

OT

OG

RA

PH

S B

Y C

HA

RL

ES

MA

RD

EN

FIT

CH

ORCHID PORTRAITsti l l have success with vegetativepropagation of orchids that normallymake a single growing point. Thesemonopodial genera include all of theVanda and Phalaenopsis relatives.Look for small offsets at the base ofmonopodial orchids. These can besafely cut off once they have five ormore healthy roots. Phalaenopsis mayform plantlets on the inflorescence.Some hybrids of Phalaenopsis equestrisand Phalaenopsis lueddemannianacommonly form plantlets. In mycollection, plantlets occur along withflowers on the same inflorescence. Toensure that small plantlets thrive whenremoved from the adult plant, get themrooted prior to separation. I put coarsesphagnum moss in a drained plastic potor section of plastic mesh next to theadult plant. A wire twist keeps theplantlet in the moss as new rootsbecome established. After a fewmonths, the plantlet will have roots inthe moss, a safe time for separationfrom the adult plant. Remember to makethe cut with a sterilized tool.

CUT DOWN Mature monopo-dial genera including Angracecum,Arachnis, Doritis, Renanthera andVanda benefit from being cut down tosize. As plants grow taller, sturdy newroots sprout along the top stem, belowthe growing tip. Eventually, a plantgrows taller than needed. Cut the topsection below five or more active rootsto form a more manageable plant.Growers with orchids outdoors intropical settings can wait years to dothis. Growers with orchids indoorsprefer to manage shorter plants.

ABOVE RIGHT Dendrobium canes (mature

pseudobulbs) laid on moist sphagnum

moss will sprout buds from dormant

“eyes,” thus making vegetative propagation

easy.

OPPOSITE TOP LEFT Dendrobium Super

Star ‘Dandy’ (Malones × Utopia) is

propagated by tissue culture.

OPPOSITE TOP RIGHT Dendrobium nobile

can be propagated from stem cuttings. At a

nursery in Chiangmai, the canes are cut

with a sterilized tool into short lengths and

then inserted into coconut fiber.

RIGHT Dendrobium Vimarn ‘KD Glade’

(Mary Trowse × Jiad Gold), made by T.

Orchids in Thailand, is a select awarded

clone mass propagated by tissue culture

for commercial sales. This specimen,

grown in New York, has 2¼-inch (5.5 cm)

flowers.

WWW.AOS.ORG MAY 2006 ORCHIDS 345

346 ORCHIDS MAY 2006 WWW.AOS.ORG

ORCHID PORTRAIT

PH

OT

OG

RA

PH

S B

Y C

HA

RL

ES

MA

RD

EN

FIT

CH

Safe Step To be sure a top sectionwill thrive after a cut down, give theupper roots a few months to grow intoa tree fern pole, wad of coconut fiberor other sturdy material. Having rootsprepared in this way will help the topsection quickly establish after it is cutdown. Monopodial orchids top-cutfrom spring into early summer willestablish by autumn, even without thisprerooting. Some commercial growerspropagate terete vandas and tall-growing Vanda and Arachnis hybridsby top cuttings, especially whenthousands of plants are needed for cut-flower production. You may find somehybrids offered for sale as top cuttings.

Bottom Buds Dormant buds at thebase of a cut-down orchid may growinto new plants. When I top Ang-raecum or Doritis, the base usually hasseveral sets of healthy leaves. Thisactive foliage helps support bottombuds once they sprout. To save space,you can pot a top cutting with a healthybase. Be sure the potting mix is in goodcondition. Often you can tilt a pot towash out old mix with a strong waterstream, then fill in your mix of choicearound the base, often with some rootsstill holding on to the container.

M E R I S T E M S C o m m e r c i a lvegetative propagation with tissueculture in an orchid lab is the modernway to increase special orchid clones.Under sterile conditions, a section ofhealthy active tissue (apical meristem)is excised from a vegetative bud, oftenfrom a rhizome in Cattleya types orfrom an inflorescence node bud inPhalaenopsis. Tissue is placed in asterile flask with nutrient agar. Variousgenera require different nutrient agarmixtures. Flasks are kept in motion,typically on a vibrating table or rotat-ing wheel. The motion speed andfrequency vary, depending on thestage of t issue growth and genusinvolved. Light is often from fluorescentlamps to give strong illumination withoutdanger of overheating the flasks.

Currently, all major orchid generacan be propagated with meristemtechniques except Paphiopedilum. Upto now the Slipper Orchids have notbeen commercially propagated inquantity from meristem tissue as isused widely for other orchids. I havephotographed vegetative propagationsof Paphiopedilum clones doing well onagar in flasks, but these resulted fromusing small offshoots cut off the plantbase or, in some cases, from seedling

TOP LEFT Otaara Hwa Yuan Bay ‘She

Shu’, AM/OSROC (Laeliocatonia Peggy

San × Brassolaeliacattleya Sunset Bay) is

a sympodial complex Cattleya-type hybrid

bred for color and shape that has been

mass propagated.

TOP RIGHT One method of vegetative

propagation is tissue culture. Here, tissue-

cultured plantlets at a commercial orchid

lab in Taiwan are raised for export.

ABOVE LEFT A sprouting backbulb of

Oncidium splendidum, a sympodial

orchid.

ABOVE RIGHT Sophrocattleya Royal Beau

‘Prince’ (Cattleya Princess Bells ×

Beaufort) has 3-inch (7.5-cm) fragrant

flowers. Although it is a tissue-cultured

plant, it could also be divided.

OPPOSITE TOP Growers with some

experience may want to increase the size

of their collections by purchasing flasks of

tissue-cultured plants. Here, Phalaenopsis

plantlets are being removed from flasks.

The agar will be washed off before the

plants are transplanted to pots.

OPPOSITE Ascocenda Sawita Delight

‘Orchidgrove’ (Vanda Fuchs Delight ×

Lenachai) is a select clone tissue

cultured in Thailand. The 3¼-inch (8-cm)

flowers are borne in upright spikes that

last 30 to 40 days on monopodial

plants.

WWW.AOS.ORG MAY 2006 ORCHIDS 347

t issue already in a steri le flask.Commercially, most Paphiopedilum arepropagated by gross division orsexually from seed. Rare species arepropagated sexually by crossing twoclones of superior specimens.

BENEFITS Tissue culture is anefficient way to propagate manyidentical plants from select clonesquickly. Most commercial orchidgrowers and some hobby growers usemeristem propagation to increase theirmost valuable or favorite clones.Awarded orchids are often the first tobe t issue cultured because theseclones have already been praised bythe judges. You benefit by havingsuperior orchids available at a lowprice. Before meristem propagation, itwas common to see divisions of specialclones sell ing for hundreds orthousands of dollars. Now you can addthe newest and best clones to yourcollection for $50 or less. A skillful labtechnician can often save a famousvirus-infected clone by using meristempropagation. Orchid virus infects newtissue slower than the plant grows. Byexcising only the very newest tissue,meristem plants can be grown virus-free.

MUTATIONS Mutations are rarein gross divisions. When you cut aparta clump of orchids into several plants,each division will be identical. Incontrast, propagation by meristemtissue in a lab involves culturing tissueclumps on nutrient agar with physicalagitation. The clumps of tissue are cutapart and transplanted several timesunder sterile conditions before finallydeveloping enough to be transplantedinto pots. All of these steps increasethe chance of mutations. Somecommercial catalogs mention that“mutations may occur” in descriptionsof meristem plants. Some mutations,such as pleasing color variations inthe flowers, may be horticulturallydesirable. Mutations become morelikely if a tissue-cultured plant is usedas the source of meristem to makeanother batch of propagations. Toreduce spontaneous mutations, com-mercial propagators prefer to gathertissue only from original seed-grownplants or plants propagated by gross“old fashioned” division.

Charles Marden Fitch frequentlycontributes his photographs to Orchids.1120 Cove Road, Mamaroneck, New York10543 (e-mail c.mardenfitch@worldnet.att.net).