Download Dendrobium nobile orchid growing

SoftcaneDendrobiumorchidgrowingintheRiverinaregionofNSW
-Dendrobiumnobile
Softcanedendrobiumsareepiphyteswithlong
slimpseudobulbs.Theyaresemideciduousand
candroptheirleavesastheweathercoolsin
winter.TheyarenativetonorthernIndia,
southernChina,Thailand,Laos,Burmaand
Vietnam(1)inmountainousenvironmentsat
1000to1700mwheretheyexperiencecoolto
coldtemperaturesinwinter.Intheirnative
habitattheyareexposedtotemperaturesashigh
as40°Candlowas0°C(8).
Manyhybridshavebeenproduced.Theycanbesubdividedintotwotypes,the‘English’and
‘Japanese’type.TheEnglishhybridshavemainlypink,mauve,creamorwhiteflowers.The
Japanesehybridstendtohavelargermorecolourfulflowersandlackthecharacteristic‘eye”
ofD.nobile(1).
Flowersareproducedfromnodesonmaturecanes,typicallyinspringfromAugustthrough
toNovember.Oldercanesusuallyloosetheirleavespriortoflowering(1).Theyusually
floweroncanesthataretwoyearsold,thecanelosingitsleavesinthesecondwinterand
thenfloweringinthespring,althoughoccasionallyplantswillflowerona1yearoldcane
thatstillhasitsleaves(3,4,8).Floweringinspringusuallycommencesoncetemperatures
reach18°C(5).
Plantsdeveloptwosmallleavesatthetopofthecanewhencoldtemperaturesinautumn
terminatethegrowingpointandencouragethedevelopmentofflowerbuds.Iftheydon’t
terminatetheirupwardgrowth,somegrowerspinchoutthetoptopreventcanesbecoming
toolong(8).
Theseorchidscanbegrowninaprotectedshade-houseintheRiverinaprovidedtheyare
protectedfromwinterrain,frostsandgivenplentyoflight.Theycanalsobegrowninacool
glasshouse.
Temperaturerequirements.
TheseorchidsarecoolergrowingthantheCooktownOrchid,Dendrobiumphalaenopsis(syn.
Vappodesphalaenopsis)andpreferatemperaturerangeof3°Catnightinwinterto32°Cin
thedaytimeinsummer,howevertheywilltoleratetemperaturesashighas42°Candlowas
3-4°C(5)oreven0°Cforshortperiods(6,8).Theyneedaboutamonthoflowtemperatures
of10-13°Cinautumn-wintertotriggerflowerbuds(6).Theymustbeprotectedfromfrost.
Nighttimetemperaturesshouldnotfallbelow5°C-10°Cwheninflower.
Light
Theypreferbrightlight(2500-3000fc)withperhaps30-60%shadeinsummerbutnodirect
sunlight(1,3,5,8).Lightshouldbeincreasedfurtherinautumn(April)andwintertomature
thecanesandtheyshouldhavefullsun(4500+fc)duringthisperiod(3,4,5)tomaturethe
canes.Plantswillfailtoflowerunlesstheyreceivegoodsunlightforanextendedperiod(9).
Ifplantsaretoocrowdedandnotreceivingsufficientlightalongthelengthofthecanethey
willonlyproduceflowerbudsatthetopofthecane(6).Ifgrownintoomuchshadetheywill
producetallgreencaneswithmanykeikiandfewflowers.With
goodlighttheyproduceshorterplumpcanes.
Humidityandairmovement
Softcanedendrobiumsneedgoodairmovementandhumidity
duringthegrowingseasonbutneedlowerhumidityinwinter.
Daytimehumidityinsummershouldbebetween50and70%.
Mistingisbeneficialduringveryhotperiodsorwherehumidity
islow.Fanscanbeusedifairmovementisnotadequate,
particularlyonveryhotdays.
Water
Thenaturalenvironmentoftheseplantshastwodistinct
seasons,ahothumidwetseasonandacoolerdryseasonlasting
2to3months.Theyshouldthereforereceivefrequentordailywateringduringthesummer
months(7),butadryspellwithinfrequentwatering(every7-10days)overwinterduringthe
restperiodfromMaytowhenbudsfirstappearwhenwateringcanslowlyincrease(6).
Howevercanesshouldnotbeallowedtoshrivelinwinterandwaterifnecessarytoprevent
this(1).Allowingthepotstodrybeforeeachwateringassistsinreducingfungaland
bacterialinfections(5).
Thedryspellandrestinwinterisnecessaryforthecanestoproduceflowers,otherwiseif
keptwettheywillproducekeikisinstead(1,3).KeithRyanrecommendswateringonlytwice
perweekfromMarchtoMayandbutjustlightwateringaboutevery10daysfromJuneto
Septemberuntilfloweringisfinished(11).
Cessationofgrowthandthedormantperiodisindictedbythedevelopmentof2small
leavesatthetipofthecane(1).
Thewateringfrequencydependsonhowtheyarebeinggrown,slabsorbaskets/pots,
pottingmediumandweatherconditions.Dailywateringmayberequiredinveryhot
weatherinsummer,butthiscanbereducedwhentheweatheriscooler.
Duringcoolerweatherwaterintheearlymorningsoplantleavesaredrybytheeveningand
avoidwateringaltogetheroncoldovercastdays.
Pottingmedium
Softcanedendrobiumscanbegrowninapot,onaslaborinabasket.Theyshouldbegrown
inawell-drained,medium1-1.5cmbarkpottingmixtureconsistingof70%barkand30%
perlite(5,6).Somegrowersuseamixofequalpartsofbarkandstoneswhichcanbescoria,
bluemetalorriverpebbles(8).Anotherpopularmixis1cmbark/charcoalwithadded
perliteandvermiculite(5).Somecowmanureorbloodandbonecanbeaddedtothemix.
Plantsshouldberepottedevery2to3yearsimmediatelyaftertheyhavefinishedflowering
(6,11)andnewgrowthisstartingtoappearandareabout2to12cmlong,usuallyinlate
springorearlysummer(1).RepottingshouldbefinishedbylateOctober(11).Ideallythey
shouldnotbesubdividedwithlessthan4-5canesasgrowthmayberetardedwithlesscanes
(5).Theyshouldnotbeoverpotted,usingthesmallestpotpossibletoaccommodatethe
rootsusuallynolargerthan125cmdia(5)butpotsupto200cmcanbeusedforlarger
plants(11).Whengrowninpots,squatshapedpotsusedtobepreferred(5)butsuccessful
SydneygrowerKeithRyanhasfounddeepernurseryshapedpotsproducelargerplantsand
biggerflowers(11).Gravelorstonescanbeplacedinthe
baseofthepottopreventplantstopplingoverwhenin
flower(3).
Onlytherootsshouldbeinthecompost.Caneswillrotif
thebaseeyesareburied(5).
CoatanycutsurfaceswithMancozebanddonotwater
plantuntiltherootshavedriedandtheMancozebhas
driedandsealedthecutsurfaces(5).Keeptheplantin
heavyshadeuntilithasrecommencedgrowing(5).
Theyusuallyrequirestakingduetotheirtallgrowinghabitandespeciallyafterrepotting.
Alternativelythecanescanbeallowedtohangdownwhengrowninabasketoronaslab.
Whenthenodesonoldercanesstarttoswelltheyshouldbestakedtosupporttheflowers.
Fertilizers
OnlyliquidlowNfertilizersshouldbeappliedatquartertohalfstrengthregularlyduringthe
growingseason,aboutevery2to3weeksuntilApril-Maywhenfertilizingshouldstop(7,8).
SomegrowersrecommendstoppingallfertilizerinlateFebruary(11)orearlyMarch(6)to
reducekeikidevelopment.Afortnightlyhighpotassiumfertilizerapplicationis
recommendedbetweenNovemberandApriltopromoteflowering(3,5).
Nofertilizershouldbeappliedwhiletheplantsaredormant(midMay-October)andwait
untilnewgrowthisabout50-70mmlongbeforefertilizing(11).Ascanesmature,switching
toahighpotashfertilizerassistsflowering(5).Slowreleasefertilizersarenotrecommended
astheymayreleasefertilizerduringthewinterrestperiod(5).Halfateaspoonofbloodand
boneperpotcanbegiventolargerplantsandlessforsmallplants(11).
Somegrowerssuggesttheuseofawettingagent(horticulturaldetergent)at½mlperlitre
waterwiththefertilizerisessentialtoassisttheabsorptionofthefertilizerbythecompost
(5).
Keikis
Therearenumberofreasonswhyplantsmayproducealotofkeikisoraerialgrowths.
Possiblecausesincludeifrootsaredamaged,theyreceivetoomuchwaterorfertilizer
duringtheirwinterrestperiod(1,11),particularlynitrogenfertilizer(3),donotgetalow
temperaturechillinautumn(11)orareintoomuchshade(5,6,7,11).Keikiscanbe
removedandpottedoncetheyhavedevelopedrootswithgreentips,preferablyonceroots
areatleast6cmlong.Somegrowersrecommendleavingkeikisonthestemforatleast12
monthsandnotremovingthemuntiltheyoungestleaveshavelosttheirgloss(11).
Plantsproducekeikisattheexpenseofflowerssoitisnotsomethingtobeencouraged.
Sprays
TheSaintAugustineOrchidSociety(10)websiteadvisesthatcopperspraysshouldnotbe
usedondendrobiumsforthecontrolofbacterialdiseases.
Kelthaneissuggestedformitecontrol,Mancozebforfungalspotting,andwhiteoilevery2
weeksforscale(5).
VarietiesfortheRiverinaregionofNSW
Foradetailedlistofthebestvarietiesforcoolgrowingconditions
experiencedintheRiverinaregionofNSWreferto“Australian
GardeningFlora’sOrchids”andothersiteslistedinthereferences
below(2).Localgrowersarealsoagoodsourceofcoolgrowing
plants.InadditiontoD.nobile,otherIndianDendrobiumsthat
comefromhighaltitudeandtolerateMelbournewintersincludeD.
chrysanthum(1000-2000m),D.fimbriatum(1500m),D.aphyllum
(syn.D.pierardii,1000m)andD.gibsonii(700-1700m)(9).
Intergenerichybrids
MosthybridshaveDendrobiumnobileintheparentage.Hybrids
havelargerflowersandagreatercolourrange.Dendrobium
CassiopeisahybridofD.nobileandD.moniliforme.
Acknowledgementsandfurtherreading:
Thisinformationsheethasdrawnoninformationbylocalgrowersandthereferenceslisted
below.
1. Soft-caneDendrobiumsbyAHope.http://www.oscov.asn.au/articles/softdend.htm
2. GardeningAustraliaFlora’sOrchids.ABCBooks(2005).
3. Culturalnotes:Howtogrowsoftcanedendrobiums.
http://www.oscov.asn.au/articles2/cultsoftden.htm
4. Howtogrowsoftcanedendrobiums.
http://www.oscov.asn.au/articles4/growsoftden.html
5. Softcanedendrobiumorchids.http://www.bribieislandorchidsociety.com/wpcontent/uploads/file/orchidgrowing/Growing%20Soft%20Cane%20Dendrobium%20
Orchids.pdf
6. Elanbeeorchids.Softcanedendrobiums.
http://members.optusnet.com.au/bdobson/Soft%20Cane%20Dendrobiums.html.
7. SoftcaneDendrobiumsbyK.Ryan.
http://www.parramattaorchidsociety.org/Cultural%20Notes.html
8. Growingsoft-canedendrobiumsinsouthernVictoria.ByMichaelPender.
http://www.oscov.asn.au/articles3/densoft.htm
9. Willitgrowcold?byBrianMilligan.OrchidSocietiesCouncilofVictoria.
http://www.oscov.asn.au/articles2/cold.htm
10. StAugustineOrchidSociety.Orchidpestsanddiseases.
http://staugorchidsociety.org/culturepests-diseases.htm
11. GrowingSoftcaneDendobiumsbyKeithRyan.AustralianOrchidReview(2015-2016)
Vol80,No6.pp21-35.
Yourcommentsandsuggestionsonthisculturalguidearewelcome.
[email protected]
Updated2/2/2016
Thesenotesareintendedasaguideonlyandarecomposedfromavailableinformationandlocalexperience.
TheWaggaWaggaOrchidSocietyanditsmembersarenotresponsibleforanylossordamage.