Download Cymbidium Orchid Growing - Wagga Wagga Orchid Society

Cymbidiumorchidculture-intheRiverinaregionofNSW
Cymbidiumsareoneofthemostwidelygrown
orchidspeciesintheworld.Theyareregardedasone
oftheeasiestorchidstogrowincoolwinterclimates
suchastheRiverinaregionofsouthernNSW.They
cangrowoutsidewithprotectionfromfrostsand
someprotectionfromthesummersun.
Cymbidiumsarenativetotropicalandsubtropical
Asiawithabout52speciesbeingidentified(1,2).A
furtherthreespeciesarenativetonorthernand
easternAustralia.
ThethreeAustraliannativesare;
Cymbidiumsuave,whichgrowsfromtheNSWsouthcoasttotheAthertonTablelandsinfar
northQueenslandandhascanesratherthanpseudobulbsthatcontinuetogrowandflower
foranumberofyears(9).Itrequiresaconsiderableamountofsunshineandisthecoolest
growingofthe3Australiannatives(9).
CymbidiummadidumgrowsfromnorthernNSWtoCapeYorkinnorthQueensland.It
growsintreesandfallenlogsandprefersamorehumidenvironment(9).
CymbidiumcanaliculatumgrowsintheKimberlyregioninnorthwestWA,theNorthern
Territory,QueenslandanddowntotheHunterRiverregionofNSW.Ithasovoid
pseudobulbsupto15cmlongandgrowsinrottingcrevassesintreesandprefersadrier
habitat(9).
Australiannativecymbidiumshoweverhaveverysmallflowersandneedtobebredwith
otherspeciestoachievespectacularpendulousflowers.AustraliannativeCymbidiumsand
particularlyC.madidum,needmoreprotectionfromcoldnightsthanmanyofthehybrids,
andmayneedadditionalheattoflowerwell(1).
ManyoftheoriginalCymbidiumspecieshavebeencrossedtoformcomplexhybridsto
createmorevigorousplantsandawiderrangeofcoloursandflowershapes.
TherearetwobasictypesofCymbidiums,thosewithuprightflowerracemes(stems)and
thosethatarependulous,thelaterareusuallygrowninhangingbasketsorpotstobetter
displaytheflowers.Plantsvaryinsizefromshortandcompact
tolargeandspreading.
Cymbidiumhybridscanalsobegroupedonthebasisofflower
sizewithminiatureunder6cm,intermediate(6-9cm)and
standard(over9cm)flowersizes.Flowersarelonglastingand
canlastover2monthsforawholeraceme.Cutabout10mm
fromthebaseofthespikeeachweekandchangethewaterto
maximizethelifeofcutflowers(8).
Cymbidiumsdonothavearestperiodandshouldbekeptmoist
andgrownvigorouslyallyearround(2,8).Hybridscanflowerat
mosttimesoftheyearalthoughthepeakfloweringperiodis
winterandspring(1).
Temperaturerequirements
Plantswilltoleratethetypicaltemperaturesexperiencedinthe
Riverinaprovidingtheyaregivenprotectionfromfrostsin
winteranddirectsunduringthehottestpartoftheyear.
Shadeclothwillnotgivesufficientprotectionfromseverefrost
andtheyrequireaplasticorpolycarbonaterooftoprovide
someprotectionorbelocatedagainstabrickheatretainingwall
(7).Anenclosedplasticgreenhouseorglasshouseisthoughtto
giveabout2-3°Cextraprotection(7).Additionalheatisusually
requirediftemperaturesareexpectedbelow-4°C,particularlyif
theyareinspike.Flowersdonottoleratethesamerangeof
temperaturesasplantsdoandshouldbekeptwithina
temperaturerangeof5-25°C(8).Theywillstopactivelygrowing
oncetemperaturesexceed27°C.
Generallytheydonotrequireadditionalcoolingorheatingalthoughtheydobestifgrown
inashadehouseorunderanorthfacingverandahwhereconditionsarelessvariable(4).
Theywilltoleratetemperaturesupto42°Canddownto0°Cprovidedtheyareprotected
fromfrost.Plantswillneedadditionalwateringormistingonveryhotdays.Mosthybrid
varietiesneedanighttimetemperaturedropofatleast10°Cinsummereveningstoinitiate
flowering(2).SuchatemperaturedropisreadilyachievedinsouthernNSW.
Light
Theyneedtoreceivesunlightformostofthedayiftheyaretoflowerwellandasmuchsun
aspossiblewithoutburningtheirleaves(1,8).Growingundera40%shadeclothis
consideredoptimumintheRiverinaexceptinwinterwhentheywilltakefullsun(5).Plants
needtobeapalegreencolouriftheyaretoflowerwell(1).Iftheleavesaredarkgreen
theyareprobablynotreceivingsufficientsunlight.Theleaveswillburniftheyreceivedirect
suninthemiddleofthedayinsummer.Theycanbegrownunderatreethatprovideslight
shadeoncetheriskoffrostispast.Yourhandshouldcastalightshadowwhenpassedover
theplant(4).
Humidityandairmovement
Maintaininghighhumidityisnotasimportantwithcymbidiumsasotherspeciesand
mistingspraysaregenerallynotrequiredexceptonextremelyhotdayswithtemperatures
greaterthan40°C.Havingadampfloortothegreenhousewouldbeadvantageousinhot
weather.
Water
Thewateringregimewillvarywiththepottingmixandweatherconditions.IntheRiverina
regioninsummer,wherehumidityislowandtemperaturescommonlyreach35-38°Cor
more,itisrecommendedtowatertheplantsevery2-3dayssothatwaterrunsoutthe
bottomordailyinveryhotweather(4,8).Inwinter,wateringonceevery7-14daysor
longermaybesufficientandpreferablyonsunnydays.Cymbidiumsmustbegiven
sufficientwatertopreventthepseudobulbsshriveling,astheycannotberehydrated.
Shriveledbulbsmaynotproduceflowershoots.Plantsalsoneedmorewaterwhenin
floweraswaterlossisgreater(4).Avoidwettingtheflowersasthismaymarkthem.
Inverycoldweatherwithrisksoffrostskeepplantsdrierthannormal(7).
Itisbesttowaterinthemorningsoplantsare
drybytheevening,particularlyinwinter(8).
Don’twatertheleavesintheheatofthedayin
summer.
Ifleavesdevelopdarkbrowntipsthiscouldbea
signofoverwateringorpoordrainage.
Pottingmedium
Cymbidiumsarevigorousgrowersandneed
frequentrepottingastheyexpandandfilltheir
pots.Theyshouldberepottedassoonasthey
finishfloweringorinMarchbeforecoldweathercommences(8)andnotinhotweather.
Astheyhavefairlycourserootstheyshouldbegrowninacoarseorchidpottingmixthat
allowsgooddrainageandaeration.Mixesvarywithwateringregimebutatypicalmixin
thisregionis60%8-18mmbarkmixedwith40%perliteorscoriatoallowairtopermeate
themix.Smallseedlingsrequireafinermixwith5-10mmbark(4).Withawelldraining
openmixitismoredifficulttooverwaterplants.
Normalnurseryshapedpotsareusedratherthanthesquatpotspreferredbyotherorchid
species.Topromotegooddrainagethebottom5cmofthepotcanbefilledwithlumpsof
polystyreneorcoarsegravelandthepottingmixofbarkandperliteplacedontop.
Whenrepotting,placecompostuptothelowerthirdofthebulbswhichensuresrootsstay
moist.Whenre-pottingasmallplantitmaybebestjusttopot-onintoalargerpotandjust
addcompostaroundthesideofthepotwithoutdisturbingtheroots(8).
Whatevermixisused,watershoulddrainfreelyfromthepotwhenwatered.
Cymbidiumsflowerbestwhentherootsfillthepotsotheyshouldnotbeover-potted(1).
Largerplantstendtoflowerbetterandwhensubdividingaminimumofoneoldbackbulb
andatleasttwobulbswithleavesplusanewgrowthorleadmustbepresentiftheplants
aretoflowernextyear.Keepplantsaslargeaspossiblewhendividing(4).
Plantsshouldbekeptoffthegroundtopreventslatersandwormsenteringthepotand
decomposingthepottingmix.
Fertilizers
Cymbidiumsareregardedasheavyfeedersastheycanproducealargeamountofgrowth
(1).Theregularapplicationofhalfstrengthsolublefertilizerisrecommendedeveryweek
fromSeptembertoMay(4).Theuseoffertilizerswithalowernitrogencontentandhigher
phosphorusandpotassiumcontentjustpriortoflowerspikeformationinlatesummer-
earlyautumnisrecommendedtopromoteflowerspikesratherthanexcessivevegetative
growth.
Analternativestrategyistheapplicationofaslowreleasepelletedfertilizertwiceperyear
inspringandagaininmidsummer.
Ateaspoonofdolomitelimeperplantisrecommendedtwiceperyeartoprovidethe
correctpHandagoodsupplyofmagnesium(1).TheoptimumpHformostcymbidiumsis
about5.5-6.5andlimeshouldbeaddedifthemixbecomestooacidasaciditywillcause
lossofroots(6).TheexceptiontothisistheAustraliannativeCymbidiumsuavefromnorth
QueenslandwhichisreportedtopreferamoreacidpHaround4to5(andlimeordolomite
limeshouldnotbeappliedtothisspecies.
Epsonsalts(MgS04)twiceayearisalsorecommendedforadditionalMg.
Hybrids
Speciescymbidiums(thosethatoccurnaturallyinthewild)arenotaswidelygrown,most
peoplechoosingtogrowhybridswhicharelessdemandingintheirrequirementsandhave
agreatervarietyofcoloursandflowershapes.
ThethreeAustraliannativespecieshavesmallerflowersandpendulousracemeswithup
50flowersoneach(seepicturebelow).Theyaremostlygrowninhangingbasketsor
suspendedpots.Afullerdescriptionofthespeciesandvarietiescanbefoundinthe
excellentbooksbyFraseretal.(2013)(1)andABCAustralianGardeningFlorabook(2005)
listedbelow(2).
IfCymbidiumsfailtofloweritcanbedueto(1)theplantbeingtoosmall,seedlingscan
take5yearstoflower(2)theplantisintoolargeapotforthesizeoftheplant(3)toomuch
Nfertilizerisencouragingvegetativegrowthinpreferencetoflowerrspikes,itmayrespond
toadditionalKandPfertilizer(4)theplantisintoomuchshadeandnotreceivingsufficient
lightinlatesummerandautumn.
AdetailedCymbidiumgrowingguidefor
southernAustralianclimatesisalsopublished
onthewebbytheAustralianOrchidNursery
(4)andTheOrchidSocietiesCouncilof
Victoria(seebelow).
Furtherreadingandacknowledgements
Theinformationinthisguideisbasedonlocal
growerexperiencesandthereferencescitedbelow.
1. GrowingOrchidsinCoolClimateAustralia(2ndedn)byMJFraser,JWright,WFerris
(2013).
2. GardeningAustraliaFlora’sOrchids.ABCBooks(2005).
3. Orchids,Apracticalhandbook.ByBandWRittershausen(2001).
4. CymbidiumgrowingguidebytheAustralianOrchidNursery.
http://www.australianorchids.com.au/pages/growing-cymbidiums
5. Cymbidiumsforbeginners.TheOrchidSocietiesCouncilofVictoria.
http://www.oscov.asn.au/articles/cymbegin.htm
6. MarriedtoCymbidiumsbyJohnKenter.
http://www.oscov.asn.au/articles/cymmarr.htm
7. Cymbidiumsandfrost.http://www.oscov.asn.au/articles3/cymfrost.htm
8. CymbidiumculturebyJulianCoker.
http://www.oscov.asn.au/articles4/cymculture.html
9. TheAustralianSpeciesCymbidiumsbyFrancesandJulianCoker.
http://www.oscov.asn.au/articles6/auscyms.html
10. ArepHchecksnecessary?St.AugustineOrchidSociety.
http://staugorchidsociety.org/PDF/ArepHChecksNecessarybyHarryMcElroy.pd
f
Yourcommentsandsuggestionsonthisguidearewelcome.
[email protected]
Updated16/05/16
Thesenotesareintendedasaguideonlyandarecomposedfromavailableinformationandlocalexperience.
TheWaggaWaggaOrchidSocietyanditsmembersarenotresponsibleforanylossordamagetoplantsthat
mayoccur.