Download Zygopetalum Orchid Growing - Wagga Wagga Orchid Society

ZygopetalumorchidculturefortheRiverinaregionofNSW
Thisisasmallgroupofabout16hardyterrestrialand
epiphyticorchidsthatcomefrommidelevation
(1000-2000m)coolrainforestsinmountainous
regionsofCentralandSouthAmerica.Thelargest
concentrationofthespeciesisinBrazil.
Theyproducetallspikesoflargelonglasting
attractiveandhighlyfragrantflowersmostlyfrom
autumnthroughwinterandspring.Flowersarelong
lasting(3-4weeks)andalsolastwellascutflowers.
Mostracemeshave4to8flowersandtheycan
produceracemestwiceperyear(2).Flowerstypically
havegreenandbrownpetalsandsepalswithpurple
colourontheirlips.
Theymostlygrowtoaheightof40cmexceptforZ.
lunatathatonlygrowstoabout10cmhigh(1).
Theyareregardedaseasytogrowandsuitablefor
bothbeginnersandadvancedgrowers.
CommonlygrownspeciesincludeZ.mackayi,Z.
intermedium,Z.crinitumandZ.maxillare.Many
hybridshavealsobeenmadewiththisgenus.
Temperaturerequirements
Theyareregardedasmostlycoolgrowingorchids,althoughafew,suchasZ.lindeniae,Z.
allenianaandZ.lunataarelistedaswarmgrowersandmayrequirehigherminimum
temperatures(1)(2).ThereissomeconfusionaboutZ.maxillarewithitbeinglistedasboth
acoolandwarmgrowerbydifferentauthors(1,2).TheremainingZygopetalumspecies
prefercoolgrowingconditionssimilartocymbidiumsbutwilltoleratetemperaturesupto
40°Cforashortperiodifhumidityiskepthigher(7).Optimumtemperaturesforgrowth
wouldbe21-26°Cinthedaytimeduringsummerwithanighttimedropof6-8°C(9,10).
Theywilltoleratetemperatureswelloutsidethisrangeandalowof8°Cinwinteris
commonintheirnaturalenvironment(6).Growersreporttheywilltoleratetemperatures
downtonearzerobutitispreferabletheydonotexperiencesuchlowtemperatures(6).
Veryhightemperaturescancausebuddrop(6).Aday/nighttemperaturedifferenceof612°Cisrequiredforflowerformation.Lownighttemperaturesarethoughttoincreaseleaf
spotting(8).
Althoughcoolgrowing,theyappreciateprotectionfromthecoldoverwinteranddislike
colddampconditionsthatcanleadtounsightlyblackleafmarks.Theywilltolerate
temperaturesdowntofreezingforshortperiodsbutmustbeprotectedfromfrost(5)and
willnotdowellifsubjectedtoprolongedperiodsoflowtemperatures.Theywilltolerate
hightemperaturesforshortperiodswithoutdamage(5)buthumiditymustbekepthigher
undertheseconditions.
Light
Theyrequirebrightlightasprovidedby50-60%
shade-clothbutnodirectsun(2).Thisis
equivalenttoabout2000-3000fcbutsome
growerssaytheylikeupto4000fc(7).Leaveswill
belightyellowgreenwhenreceivingadequate
light(6,7).Theyrequirelesslightthan
cymbidiumsandleaveswillbecomeyellowand
burniflightistoostrong(3).Donotplaceunder
bencheswhereairmovementispoor.Plantswill
notbloomwelliflightisinadequate(6).Very
darkgreenleavesindicatetheyarenotreceiving
sufficientlight.Providemoreshadewhenflowers
opentoincreaseflowerlife(7).Olderleavesoftendevelopbrowntips,thisisconsidered
normal.
Ifbudsturnyellowandfallpriortoopeningthisiscausedbyinsufficientenergyintheplant
duetoinsufficientlight,largetemperaturefluctuations,theplantistoosmallorrootrot(8).
Decreasingday-lengthandlightexposureinitiatesflowerdevelopment.Thiscanbedone
artificiallybydecreasingday-lengthbyabout2hours/dayfor3-4weeks(11).
Humidityandairmovement
Theypreferhighlevelsofhumidity(40-80%)andverygoodaircirculation(6,10).Leaftips
willdryoffandfoliagespotifhumidityistoolow(1).Standingthemongravelfilledtrays
containingwaterinhotweatherwillhelptoincreasehumidity.Overheadmistingis
beneficialonveryhotdays(7)butcanalsocauseincreasedblackleafmarkingsounder
benchwateringispreferred.Wherehumidityishighgoodairmovementisessentialto
preventblackspotsontheleaves(10).Afanwillassistwiththis.
Leafspottingcanbedifficulttoavoid.Leafspotsoftenoccurifleavesremainwetfortoo
longafterwateringespeciallyinwinter(3).Colddampconditionscanleadtoblackmarking
ofleaves.Thespottingiscausedbyafungusanddoesnotappeartoaffectthevigourofthe
plants(5,12).ThespottingcanbecontrolledwithMancozebTbutisbestpreventedby
avoidingwaterontheleaves(12).Newervarietieshavebeenselectedforincreased
resistancetoleafspotting.
Water
Plantsshouldbekeptuniformlymoistbutnotoverwetduringthewholeyearwithslightly
lesswaterinwinter,wateringjustweeklyorevery2weeks,whentheyarelessactive(1,7).
Donotwaterintheheatofthedayinhotweather(12).Allowingthemtodryalittlein
winteraidsflowerformationratherthanexcessvegetativegrowth(8).Inwinteravoid
gettingwaterontheleavesincolddampweathertoreduceleafspottingandpreferably
wateronsunnydays(3,12).
IntheRiverinatheyarebestgrownwithsomecovertopreventthembecomingtoowet
overwinter.Aswithmostorchids,rainwaterispreferredovertreatedwater.Excesssalt
buildupmaycauseleaftipstodiebackandleavestofallprematurely.Ensurepotsare
drenchedthoroughlytopreventsaltbuildup(7).
Pottingmedium
Theyprefertobegrownindeeppotstoaccommodatetheirvigorousrootsystems(6).
Theyrequireafreedrainingmixofmediumsizebarkand20%perliteandshouldbe
repottedaboutevery2-3yearsafterfloweringisfinishedinspring(12).Theyprefera
slightlyacidpottingmix(7).PottingmixusedforCymbidiumsissuitable(13).
The3warmgrowingspeciesreferredtoabovearesaidtoprefergrowingonslabsrather
thanpots.IncidentallytheyarealsotheonlyZygopetalumsthatdon’thavefragrantflowers
(1).
Pot-boundorchidsthathavefilledthepottendtobeunderwateredandflowerlessso
shouldberepottedevenifthemixturehasnotbrokendown(7).
Whenrepottingtrytokeep2-3greenbulbsandjustonebackbulbwithoutleavesineach
divisionifpossible.Removeexcessbulbulbswithoutleavesastheycaninhibitflowering
(12).Removealldeadordamagedrootsasthesecanencouragerootrot.
Afterrepottingplantsshouldbeplacedinheaviershadethannormalandkeptonthedrier
sidetoallowplantstorecoverforseveralweeks(7).
Fertilizers
PlantsshouldbefedfromSeptembertoMaywithapplicationsatabout14dayintervals.A
weakhalfstrengthsolutionofbalancedfertilizercanbeappliedalternatingwithseaweed
fertilizer.AlternativelyaslowreleasefertilizercanbeappliedinOctober.Changingtoa
potassiumandphosphorusrichfertilizerduringautumnisbeneficialtopromotebetter
flowering(3)(5)(12).
Zygopetalumspecies,hybridsandintergenerichybrids.
Adetailedlistofthespeciesandtheirhybridsisgivenin
thearticlesbyHope(2),Milligan(4)andintheAustralian
GardeningAustraliaFlora’spublications(1)and
Cloudorchids.comwebsite(11)thatarelistedbelow.
Commonintergenerichybridsare;
Hamelwellsara=(AganisiaxBatemanniax
OtostylisxZygopetalumxZygosepalum),
• Propetalum=(ZygopetalumxPromenaea),
• Zygoneria=(ZygopetalumxNeogardneria).
•
AnewintergenerichybriddescribedintheAustralianOrchidReviewVol81(No1)is
Bleitzara(ZygopetalumAdvanceAustraliaxGalabstiaGreenTiger)andhasgreenpetals
withredmarking.Itisadaptedtobothcoolandwarmclimatesbutisbestgrownundera
solidroof.AlistofsomeofthelatestZygopetalumhybidssummarisedbyStephen
MonkhouseispublishedintheApril2016editionofOrchidsAustralia(Vol28,No2).
Otherintergenerichybridsinclude(11):Batemannia(Btmna.),Colax(Clx.),Galeopetalum
(Gptm.),Galeottia(Glta.),Koellensteinia(Koell.),Menadenium(Mndnm.),Mendoncella
(Mdcla.),Peristeria(Per.),Warrea(Wra.),Woodwardara(Wdwa.),Zygocolax(Zcx.),
Zygopetalum(Z.),Zygosepalum(Zspm.).
Acknowledgementsandfurtherreading
Theinformationinthisguidehasbeenobtainedfromlocalgrowersandthereferences
listedbelow.
1. GardeningAustraliaFlora’sOrchids.ABCBooks(2005).
2. ThecultivationofZygopetalumsbyA.Hope.
http://www.oscov.asn.au/articles/zygopet.htm
3. HowtogrowZygopetalums.OrchidsinVictoria.
http://www.oscov.asn.au/articles4/growzygo.html
4. TheZygopetalumalliancebyBMilligan.OrchidsinVictoria.
http://www.oscov.asn.au/articles6/zygos.html
5. ElanbeeOrchids.ZygopetalumCulture.
http://members.optusnet.com.au/bdobson/Zygopetalum%20Culture.html
6. CharlesandMargaretBakerOrchidCultureSheet.Zygopetalummackayi.
http://www.orchidculture.com/COD/FREE/FS250.html
7. CasadelasOrquideos.BasicZygopetalumCulture.
http://www.orquideas.com/growing/zygocult.html
8. Canadianorchidcongress.Zygopetalumorchids.
http://www.canadianorchidcongress.ca/cculture/zygopetalum.pdf
9. Orchidcaretips.Zygopetalumorchid.http://www.orchid-caretips.com/zygopetalum-orchid.html
10. Orchidsmadeeasy.Zygopetalumorchidcare.
http://www.orchidsmadeeasy.com/zygopetalum/
11. Cloudsorchids.com.http://www.cloudsorchids.com/culture/zygopetalum.htm
12. BankstownOrchidSociety.Zygopetalums.
http://www.bankstownorchidsociety.org.au/Zygopetalum.htm
13. Zygopetalumorchids.Nurseriesonline.http://www.nurseriesonline.com.au/plantindex/orchids/zygopetalum-orchids/
Yourcommentsandsuggestionsonthisculturalguidearewelcome.
[email protected]
Updated24/05/2016
Thesenotesareintendedasaguideonlyandarecomposedfromavailableinformationandlocalexperience.
TheWaggaWaggaOrchidSocietyanditsmembersarenotresponsibleforanylossordamage.