TOPCUTTINGVANDAORCHIDS
Vandaorchidsareamonopodialgrowingplant,whichputsimplymeansthattheycontinuetogrowverticallyupasinglestem,gettinglonger.Thisissomewhatdifferenttomanyotherorchidsthatproducerhizomesgrowingacrossapotorhost,movinginahorizontaldirection.Mostrhizomegrowingorchidshavetwoeyesorgrowthpointsoneachrhizome,allowinggrowthfromeitherpointshouldtheneedarise.However,aVandaorchidisverydifferenttothis.
AsaVandaplantgrows,newleavesbecomevisibleatthetopoftheplant.Asitcontinuestomaturethestemgrowsandtheplantbecomestaller.Thisproducesahealthyplantwiththeleavesspreadingtobothsidesofthestem,producingafan-likeappearance.Asseeninpicture1,aVandaplantshouldhaveleavesfromthegrowingtopoftheplantallthewaytothebasejustabovethepottingmediaorhostmaterial.Thishoweverisnotalwaysthecase…
Sowhathappenswhensomethinggoeswrongandtheplantdropsthelowerleaves?Thesimpleansweristhatyouendupwithaplantwhichlooksandisoftendescribedasa‘PalmTree’(asseeninpicture2).Whenthisoccursitgivestheappearanceofpoorculture,makingtheplantslookscraggily.Howeveryoucantakeactiontorestorethemtotheirfan-likeglory.
Sowhatcausesthis‘PalmTree’effect?Themostcommoncauseiscoldweather–iftheplantisexposedtothecolditwillnaturallydropthelowerleaves.Thisdoesnotmeanthattheplantissickbutsimplyithasbeenplacedunderstressbytheconditions.Othercausescanbemoreproblematicandmaybefungalorbacterialinnature.Thiswouldrequiretheunderlyingcausetobetreatedbeforeanyremedialworkisundertakenandifyouareunsureyoushouldseekassistancefromexperiencedgrowers.Itismyexperiencehoweverthatmostfungalorbacterialproblemsaffectthenewtopgrowthratherthancausingthebottomleavestodrop.Oncethedamageisdonehoweveritisirreversibleandtheeffectisthe‘PalmTree’look.
TopcuttingVandaOrchidsisonewayofcorrectingthe‘PalmTree’problem.AsVandaOrchidsgrowtallertheyoftenproduceadditionalrootsfromvariouspointsupthestem(asseeninpicture3).Innaturethesenewrootswouldattachtothehosttreeorrockforminganewanchorpointfortheplant,allowingittocontinuetothriveinitsuprightnaturalway.Luckilyfortheorchidenthusiast,thisgivesustheopportunitytoremovethebottomoftheplanteffectivelyshorteningthestemandbringingthelowestleavesbacktothepotorhost.Providedtheplanthasgrownnewrootsupthestemthisiseasilydonebycuttingthroughthestemcompletely.Itispreferabletoleaveaminimumoffournew,wellestablishedrootsattachedtothetopoftheplant.Thecutshouldbeonananglesothatwaterdoesnotgatherandallowfungusorsimilarproblemstooccur.Itisbesttocompletethiswhentherootsareactivelygrowingwithgreentips.OncedoneIliketosealthecutwitheithersomeSteri-Pruneorapasteoffungicideandallowittosittodryforadayorsobeforerepotting
intothenewmediaorattachingtothenewhost.Ifindthislimitsthestresstotheplantanditcontinuestogrowasifnothinghadhappened.
Theolderbaseoftheplantcaneitherbediscarded,orkepttoseeifitwillproduceanysidegrowthsforminganewplant.Shouldanewshootoccur,thiscancontinuetobegrownuntilitproducesitsownrootsandcanthenberemovedfromtheoriginalstemusingcuttersorasharpinstrumentandpottedon(asperpicture4).
Someplantshowever,willnotproduceanynewrootsupthestemwhichcreatesaproblem,ascuttingthetopoffthestemwithoutrootsisaskingfortrouble.Inthiscase,rootgrowthcanbeencouragedbycuttingapproximately½waythroughthestemandapplyingsomerootinghormone.Iliketoplaceathinplastictagsoakedinthehormoneintothecutandleaveitthere,asthisseemstoworkwellforme(asseeninpicture5).Withinafewmonths,ifallgoeswell,somenewrootswillappearandoncesufficientgrowthhasoccurredthenormalprocedureabovecanbeundertaken.Justatiphere,ensurethatthetopoftheplantiswellsupportedbeforecuttinghalfwaythroughthestemoryourplantmaybreakprematurely.
Byfollowingthesesimpletechniquesyoucanhavebeautifulplantswithfullleafgrowthjustasnatureintendedandbetheenvyofyourorchidgrowingbuddies.
Happygrowing.
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Picture2 Picture3
Picture4 Picture5