Gretchen Ward MasterGardenerTrainee

Mypresenta+onisn’taboutabaritesandrose…It’snotaboutarockernamed(Axl)Rose…Orahybridrosewitha‘rock‘n’roll’name…

Itdoesn’tinvolveanyevents…

orRoseandRocksculptures…orRocksnamedaBerRoses…Andit’snotaboutaRosecarvedonarock…

Arosebyanothernamewouldprobablysmellsweeterthanthese…

It would smell like…. Cistus spp.

Rockrose

Not just Cistus sp. • Thenamerockroseactuallyreferstoplantsinthreegenera,Cistus,Halimium,andTuberaria,thatwiththeSunroses(Helianthemumsp.)comprisethemajorityofcul<vatedplantsinthefamilyCistaceae• Theyareperennialevergreenshrubswithflowers• Openearlyinthemorninganddroptheircrape-paper-likepetalsbymidaDernoon• Bloomfrommid-springintosummer

Rockrose • ThefamilyCistaceaehasbetween170-200speciesineightgenera• Cistushasabout20speciesandover450cul<vars

• SpeciesofCistusprimarilydistributedinthetemperateareasofEuropeandtheMediterranean• Mostaresubshrubsorshrubsthatcomefromdrysunnyhabitats,oDenonpoorsoils

RockroseattheWaterConserva+onGardenduringourvisitinFebruary

•  Summerirriga+onismostlyunnecessary•  Preferfullsun•  Summergrowthmaypredisposetheplantstorootorcrowndiseases• Mostrockrosesresenthardpruningandquicklydecline—gentlyremoveoldgrowth•  Theyshouldbeplantedinthefalltoensuretheplantswillbewell-rootedandnotrequireirriga+onbythefollowingsummer

Cistusxargenteus‘BlushingPeggySammons’

GrowthHabit

Growth Habit •  Theycantoleratepoorsoil,heat,orcoldwindsandoceanspray• Whenplan+ng,spreadouttherootssotheygrowdeepintotheground• Maybeshort-livediftheirenvironmentalneedsareignored

Cistusxaguilarii'Maculatus’=spoTedwhiterockrose

Growth Habit •  Itisadicot,withopposite,simple,usuallyslightlyrough-surfacedevergreenleaves,2-8cmlong.Inafewspecies(suchasC.ladanifer),theleavesarecoatedwithahighlyaroma+cresincalledlabdanum

•  LeavesaresoBgreen,gray,orsilver

•  Theyhaveshowy5-petaledflowersrangingfromwhitetopurpleanddarkpink,inafewspeciesthereisadarkredspotatthebaseofeachpetal

•  Thishybridcul+var,Cistus×purpureus,wasfirstformally

describedin1786

Pests and Problems CistusDiseases•  Rockrosesaregenerallypestanddiseasefreebutmaydevelopafewcommongardendiseases•  PowderyMildew•  Ver<cilliumWilt(afungaldisease)•  SootyMold•  Botry<sBlight(graymold)

Insects•  Aphids

Cistusvillosus‘ChantryFlat’

Environmentaldisorders•  Mineraldeficiencies•  Nutrientandmineral

excesses•  Poorwatermanagement

Cistusalbidus

RockinaRoseGarden

GretchenWard Presentationfor“What’sThatBloomingThing”--Cistusspp.

Mypresentationisnotaboutabaritesandrose,orarockandrollernamedAxlRose,anditscertainlynotaboutafancyhybridrosewitha“rocknroll”name.Anditwon’tgiveyouinformationaboutrockgardensandrosegardens,oranyotherrockorroserelatedname,andtruthbetold,arosebyanothernamewouldprobablysmellsweeterthanthese,infactitwouldsmelllikeaCistus,otherwiseknownasarockrose.ThegenusCistusisknownasarockrose.Itisnotaroseasonemightthink.Ithasnothornsandrequiresaminimalamountofwater,doesn’tliketobepruned,andisaverylowmaintenanceplant.ThenameCistusisderivedfromtheGreekwordkisthosorkistos,classicalnamesforvariousspecies.Rockroseisacommonnameforseveralplants.NotonlyinthegenusCistus,butalsoTuberaria,HalimiumorX.Haliiocistus.TheXHaliocistusgenusincludescrossesofHalimiumwithCistus.AlongwiththeSunroses(ingenusHelianthemum)theyrepresentmostofthecultivatedplantsinthefamilyCistaceae.Cistusisawoodyevergreenshrubthatflowersprofusely,ifonlyforashortperiodoftime.Theyproducespectacularyellow,pink,white,orpurplefive-petaledblooms,from1to4½inchesacrossonshrubsthatvaryfrom1-6feetinheight.Thecommonnameof‘rose’intheirdescriptioncomesfromthesimilaritytheybeartoold-fashionedsinglerosesmadefromcrepepaper.Theyarenotedfortheirdarkspotsatthebaseofthepetal.Theyopenintheearlymorninganddroptheirpaper-likepetalsbymid-afternoon,withanotherflushofflowersopeningthefollowingmorning.Theirspectacularbloominglastsforamonthortwofrommid-springintosummer.ThefamilyCistaceaehasbetween170-200speciesineightgenera,Cistushasabout20speciesandover450cultivarswiththespeciesofCistusdistributedinthetemperateareasofEuropeandtheMediterranean.Mostareshrubsthatcomefromdrysunnyhabitats,oftenonpoorsoilswhichinmanyrespectsmakethemextremelysuitableforgardensinSanDiegoCounty,astheyseemtopreferpoorsoilconditions.GrowingtheminSanDiegoseemslikeagoodchoiceastheirneedforsummerirrigationisalmostunneeded,theypreferbeinginfullsunandwhiletherearesomeissuesthatoccasionallyarise,theyaremostlyeasytogrow.Theydon’tliketobeprunedmuchandmostlycanbeignored.Plantinthefallforspringblooms.Thehardinessofrockrosescanbevariable,buttheyshoulddofairlywellinourareaastheyareratedasgrowableinUSDAzones7to10.They’renotonlyabletodealwithpoorsoilandlotsofsun,buttheyaregoodalongthecoastandcaneventoleratesomeoceansprayandmistymornings.Themainissueseemstobethatiftheygrowtooquicklybecauseofoverwateringtheycandeclinemorequicklyandneedtobereplacedsincetheydon’ttakewelltobeingcutback.Soinsteadofbeinginyourgardenforseveralyears,maybeasmanyasten,theymightonlylasthalfthattimeiftheygrowtooquicklyandgettooleggy.Cistusisadicot,withopposite,simple,usuallyslightlyrough-surfacedevergreenleaves.Inafewspecies(suchasC.ladanifer),theleavesarecoatedwithahighlyaromaticresincalledlabdanumwhichcanbeharvestedandhashistoricallybeenusedinperfumesandincense.Theleavesaresoftgreen,gray,orsilverandtheirflowercolorsarefew,butshowy.SincethegenusCistusisnotnativetoNorthAmericanthereareveryfewdiseasesthatimpactit.Rockrosesareusuallypestfree,althoughsomecommongardendiseasesmaydevelopsuchaspowderymildew,verticilliumwilt,andmaybesootymoldandgraymold.Aphidsareabouttheonlyinsectproblemtheytypicallyaresubjectto,andofcoursethereareenvironmentalproblemsthatmightpop

GretchenWard Presentationfor“What’sThatBloomingThing”--Cistusspp.

upsuchasmineralandnutrientdeficienciesorexcesses.Thebiggestproblemisgettingthewatermanagementcorrectforthisgenus.Mostgrowersofrockrosesseemtolikethemfornotonlytheirprettyspringtimeflowers,butalsoforthefactthattheyliketobeignored.They’reaplantthatthrivesonbenignneglectandwillrewardyouwithbeautyandgreeneryyear-round.ReferencesBaldwin,Randy2020 “TheRockroses,”SanMarcosGrowers,accessedonlineat

https://www.smgrowers.com/info/cistus.asp,March2,2020.Bell,Neil(websitecreator,OregonStateUniversityExtensionService)2020 “Rockrose(Cistusspp.andHalimiumspp.)EvaluationforWesternOregon”–accessedonlineat

https://agsci.oregonstate.edu/osu-nursery-greenhouse-and-christmas-trees/rockrose-cistus-spp-and-halimium-spp-evaluation-western-oregon,March2,2020

Page,RobertG.2019 TheCistusandHalimiumSite.Accessedonlineathttp://www.cistuspage.org.uk/,March2,2020Stallsmith,Audrey2014 “Rock'nRoses:CistusandHalimium”–accessedonlineat

https://davesgarden.com/guides/articles/view/4866,March2,2020.