Westerndvdes-644

1HowToPruneConiferousEvergreenTreesBulletinNo.
644D.
W.
McConnellR.
L.
MahoneyW.
M.
ColtA.
D.
PartridgeCooperativeExtensionSystem2TREESERVICEEvergreenshadetreesinthecitiesandtownsofIdahoprovidebeautyandcomfort.
Unfortunately,thesetreesareoftenneglectedorimproperlytreatedandthus,theybecomesickly,unsightly,andhazardous.
Propermain-tenanceoftreesaroundhomesandinparkscanprovidemaximumbenefitsandminimalproblems.
Coniferousevergreensnormallydonotrequirepruning.
Attimes,however,carefullyplannedpruningisanecessarypartofacompletetreemaintenanceprogram.
PruningObjectivesPruningistheremovalorreductionofcertainpartsofaplantthatarenotdesiredorrequired,nolongereffec-tive,oreveninjurioustotheplantitself.
Theprimeob-jectiveistomaintainthenaturalbeautyoftheplantandkeepitashealthyaspossible(Fig.
1).
Pruningthecrownofayoungtreehelpstobringthecrownandrootsintobalance.
Ayoungtreecanbetrainedintoadesiredshapeorform,withincertainlimitations.
Inaddition,treesshouldbemaintainedtoprotecthomes,powerlines,andneighboringplants.
Itisimportant,therefore,thatthepropertyownermakewell-informedpruningdecisions.
HowToPruneConiferousEvergreenTreesD.
W.
McConnell,R.
L.
Mahoney,W.
M.
Colt,andA.
D.
PartridgeSevere,extensivepruningiscostlybothtotheland-ownerandthetree.
Suchpracticescanbeavoidedthroughregular,judicioustreatmentswhereundesirablegrowthisperiodicallyremoved.
DoINeedtoHireAProfessionalTreeSurgeonTheanswertothisquestionwilldependonseveralfactors:thesizeandlocationofthetree,yourphysicalabilityandpruningknowledge,andyouravailabletime.
Inthecaseofanylargetree,oratreenearahomeorpowerlines,youshouldcontactaprofessionaltreesur-geon.
Whenlocatingatreesurgeon,rememberthesepoints:1.
Checktheyellowpagesfor"TreeServiceCompanies.
"Avoidadssuchas"Treework,call.
.
.
"(Fig.
2).
2.
Thecontractormustbebondedandinsured.
Theworkcrewshouldhaveacopyofliabilityinsuranceinitspossessionwhileonthejob.
3.
Askforreferencesofpastworkinthecommunity.
Ifpossible,taketimetovisitoneortwoofthesesites.
4.
Requirethatthejobbeperformedona"jobba-sis,"notanhourlyrate.
Useawrittencontract.
5.
Askforafullexplanationofwhatthetreeservicecontractorthinksyourtreeneeds,whyitneedsthistreatment,andwhatheintendstodotothetree.
Ifyouhaveuncertainties,getasecondopinion.
Fig.
1.
Healthyplants.
.
.
satisfiedowner!
Fig.
2.
Usetheyellowpagestofindreliabletreeservicecompanies.
3Fig.
3.
Whentoprune6.
Don'tbeforcedintoaquickdecisionbyhighpres-sureortheofferofa"realdeal.
"Getasecondorthirdestimateofnecessarytreatmentsandcosts.
Whetheryoudecidetopruneyourtreesyourselforhireaprofessionaltreesurgeon,readthispublication,andstudytheillustrationscarefully.
Thisinformationwillalsobeusefulwhendiscussingtherequirementsofyoursituationwithatreeservicecontractor.
Ifyouhaveanyquestions,contacttheUniversityofIdahoCoopera-tiveExtensionSystemofficeinyourcountyforadvice.
WhentoPruneOneofthefirstoccasionswhenatreemayrequirepruningiswhenplanted.
Rootshavebeendisturbedorpartlydestroyed,andthebranchstructureshouldbebroughtintobalancewiththeremainingrootsystem.
Ayoungtree,ifwellprunedandtrainedinitsearlylife,willneedminimalpruninginlateryears.
Theremovalofyoung,smalllimbsisquickandsimple(Fig.
3).
Ifpruningisdelayeduntillimbsbecomelarge,theyaremoredifficulttoremoveandwillaltertheappearanceandhealthofthetree.
Thebestresultscomefromprun-ingayoung,vigoroustree.
Mostconifershavestrong,centralleadersandwillneedlittleornotrainingunlessnontypicalgrowthisdesired.
Pruningwhenplantinginvolvesthinningoutsomeofthebranchesthatwouldbecomecrowdedordevelopweakcrotchesandremovingbranchesthatcrosseachother.
Multipleleadersshouldbethinnedtofavorthestrongestorbest-formedindividual.
Forestablishedtrees,annualinspectionswillshowwhetherpruningorothertreemaintenanceisnecessary.
Again,mostconiferousevergreensneedlittleornopruninggiventhepropersituation.
Brokenorcrowdedlimbsneedingtreatmentwillbeinfrequentifthetreehasbeenproperlymaintained.
Thesizeofoldertreesofsomespeciescanbecontrolledtoalimitedextentwithcarefulpruning.
ForconiferousspeciessuchasGrandfir,Westernwhitepine,andthespruces,latewintertoearlyspringisthepreferredtimetoprune.
Donotprunelivebranchesduringthegrowingseason—latespringthroughsum-mer.
Atthistime,thebarkismoreeasilydamaged,cre-atingahighriskforfungalinfection.
Douglas-firbarkiseasilydamagedandmaynotproduceenoughresintoprotectawoundfromfungalinfection.
WithDouglas-fir,itisunsafetoprunebrancheslargerthan11/2to2inchesindiameterduetothisproblem.
Pruningspruce,however,stimulatesresinproductionthathelpsprotectcutsurfacesfromfungalinfections.
Withcare,deadlimbsmayberemovedatanytimefromconiferoustrees.
Deadlimbsmaybeidentifiedbytheirlackofgreenfoliageorlivetissueunderthebark.
Useaknifetoscrapeawaytheouterbarkofthesuspectbranch.
Iftheexposedtissueisdry,thebranchisdead.
ToolsforPruningHandsawsthatcutonthepullstrokearerecom-mendedforpruningastheyprovideexcellentcontrolwhilebeingtheeasiesttouse.
Polesawsareusefulforpruningbranchesthatarelessthan20feetabovetheground.
Sharpandwell-maintainedbypasshandshearsarealsorecommendedfortheremovalofsmall,lightbranches.
Figure4illustratesthepreferredtoolsforpruning.
6to12feetFig.
4.
Recommendedpruningtools.
4Hedgeshearsshouldnotbeusedastheydonotre-movebranchescleanly.
Likewise,anvil-cuthandshearstendtocrushtheprunedstem,whichslowsthehealingprocess.
Chainsawsareonlyrecommendedforprelimi-naryorroughcutsinpruning.
Mostpruningshouldbedonebeforebrancheseverreachasizethatrequirestheuseofachainsaw.
Theuseofaxesforpruningshouldbeavoided.
Theroughstubsleftbythistreatmenthealpoorly;thereisalsoahigherriskofneedlesslyinjuringavaluableshadetreeoryourself.
GuidelinesforPruningConifersBeforepruning,consideryourobjectives,suchasthedesiredsize,shape,anddensityofthetree.
Attimes,noamountofcarefulpruningwillcontroltheplanttoyoursatisfaction.
Insuchacase,removalandreplacementwithadifferentplantmaybethebesttreatment.
Thedensegrowthcharacteristicsofjuniper,arborvi-tae,andsimilarspeciesproduceadeadinteriorzonewherethetwigsandbudsarekilledfromsevereself-shading(Fig.
5).
Thedeadzonelimitstheextentofprun-ing.
Ifitisexposedbyseverepruning,newshootswillnotdevelopfromtheexposedarea.
Theresultisade-formedandunsightlyplant.
Afterlocatingthedeadzone,lookinthelivezoneforlimbsthatcanbecompletelyremovedorforlimbsthataredead,diseased,orbroken.
Ifabranchistobepartiallyremoved,makesuretoleaveagreenshootnearthecutorelsethelimbwilldie.
Thegreenshootwillproducevigorousgrowthduringthefollowinggrowingseason.
Thegrowthhabitsofpinesdifferfromtheotherever-greenspeciesmentionedabove.
Pinesdonotdevelopaprominentdeadzonebecausetheiropencrowndoesnotcausesevereself-shading.
Somelowerandinnerbranches,however,willperiodicallydiefromself-shad-ingandnormalgrowthhabits.
Pinescharacteristicallyproducebranchesingroups,orwhorls,animportantfacttoconsiderinproperpruning.
Seefigure6forexamplesoftheseandothertreeparts.
Again,beforepruning,consideryourobjectivesforthetree,especiallyconcerningthesizeandshape.
Smallpinesareoftenprunedtoproduceapyramidal,Christmastreeform.
Pruningwillshortenthespacebetweenthewhorlsofapine,producingafuller,morecompactplant.
Beginbycuttingbackthecentralleaderatthetoptoan8-to12-inchstub(Fig.
7A).
Thiscutshouldbejustaboveawell-formedbud.
Ifpossible,selectabudonthenorthsideofthebranchinordertoformthestraightestgrowth.
South-facingbudstendtogrowout-wardratherthanupward.
Next,prunethesidebranchesaroundthetopuntiltheyare4to6inchesshorterthanthecentralleader.
Continuepruningtheremainingsidebranchesinamannerthatwillproduceauniformpyramidshape(Fig.
7B).
Iftheleaderofatreehasbeenbroken,asidebranchcanbetrainedtobecomethenewleader.
ThisprocesswouldoccurnaturallybutusuallyresultsintwoormoreleadersidebrancheswhorlinternodemainstemortrunkFig.
6.
Importantpartsofaconiferousevergreentoknowwhenpruning.
Fig.
5.
Deadzoneofjuniperandarborvitae.
deadzone5branchescompetingwithoneanotherasmultiplelead-ers.
Topreventthis,cutbacktheremnantofthemainstemtoapointjustabovetheuppermostwhorlofbranches(Fig.
8A).
Pruneoneofthebranchestoalengthof6to10inches.
Gentlybendthelimbtoanuprightpositionandholditinplacewithastakeandstring(Fig.
8B).
Finally,prunetheotherbranchesinthewhorlbacktorestorethepyra-midalshapeofthetree.
Pruningpineswillstimulatebuddevelopmentfromtheneedlebunchesbeloweachcut.
Thesebudswillincreasethedensityofthetreebyproducingmorelimbs.
Thebranchesoflargerpinetreeswillrespondinasimilarfashion.
Besuretopruneonlythenewergrowth,leavinggreenneedlesonthecutbranchestoproducemorebuds.
Whenpruninglargerevergreentrees,itisoftendesir-abletoremovelowerbranchesinordertoimproveac-cessaroundthetree.
Asmuchasone-thirdofthecrownoffull-crownedevergreensmayberemovedwithoutaffectingthevigorofthetree(Fig.
9).
Thelowercrown,however,shouldonlyberemovedwhenabsolutelynec-essary.
Thefullycrownedtreeinfigure9isobviouslysuperiorinbeautyandutility.
Fig.
8.
Howtotrainabranchtoreplaceabrokenleaderonaconiferousevergreen.
Fig.
7.
Twostepstopruningtheleaderofapinetree.
StepAStepBStepAStepB6Whenremovingaheavylimb,followathree-cutpro-cessasfollows.
Makethefirstcut1to2feetawayfromthebaseofthelimbontheundersideofthebranch;thiscutshouldbemadethroughapproximatelyone-thirdofthebranch.
Makethesecondcutfromabove,justout-sidethefirstcut;itshouldcompletelyseverthebranch.
Finally,makethethirdcutjustoutsidethelimbcollar,par-alleltotheattachedlimbortothetreetrunkifattachedthere.
Figure10showsthesethreebasicstepsinpruning.
Whenmakingthisthirdcut,supportthestub.
Thisprocesswillpermitthebasalcuttobemadesmoothly,withouttheriskofbindingasaworpeelingthebark.
Inlargerevergreentrees,removeanydeadorbrokenbranchesandanybranchstubs.
Besuretomakethecutsurfacesasflushwiththebarkaspossible.
Forbranchesthatnoticeablyswellwheretheyjointhemainstem,makethefinalcutatthepointwherethebranchbeginstoflare.
Thisleavesasmallercutsurfacethatwillhealmorerapidly(Fig.
10,cut3).
Also,anybranchesthatap-pearcrowdedshouldbethinnedtofavorasingle,strongerbranch.
Strongbranchescanbeidentifiedbythewidebranchinganglebetweenthetrunkandthelimb.
DoNotTopEvergreens!
Anunsatisfactoryapproachtotreemaintenanceforanytreeistotopit.
Toppingistheremovalofallbranchesofamaturetreeaboveanarbitraryheight,leavingun-natural,grotesquestubs.
Largeevergreentreesdonotrespondwelltotopping.
Theremovaloftheuppermainstemthroughtoppingopensthetreetointernaldecay,disease,ordamaginginsects;italsoremovesthemostproductiveportionofthecrownofthetree.
Theresultisthatthetreebecomesahazardtoitself,neighboringtrees,andyourproperty(Fig.
11).
Thepracticeoftoppingtocontroltreesizeorgrowthisnotjustified.
Ifthetreeistoolargetofitthespace,itshouldberemovedandreplacedwithasmallerspecies.
Beawarethatunprofessionaltreeservicecrewsusethisapproachbecauseittakeslittleskillandiseasiestforthemtoperform.
Donotletyourselfbepersuadedthattoppingservesyourbestinterest;bothyouandyourtreewillsufferfromsuchmistreatment.
PruningMatureEvergreensNearPowerlinesWestronglyrecommendthatyouhireaprofes-sionaltreemaintenanceservicewhenpruningnearoverheadpowerlines.
Alwaysnotifythepowercompanybeforebeginningwork.
Pruningaroundpowerlinesisnecessarytopreventlinedamageandotherhazards.
Itshouldbedone,however,inanaestheticallypleasingmannerthatisalsogoodforthetree.
Directionalpruninginvolvestheopeningofpathsthroughthecrownofthetreeforthewires.
Whilethismethodmayappearmoreexpensivethanothers,itgivesFig.
9.
Beforeandafter:theremovaloflowerbranchesfromaconiferousevergreenwillimproveaccessaroundthetreewithoutaffectingitsvigor.
BeforeAfterFig.
10.
Usethreecutswhenremovingalargebranch.
Fig.
11.
Atoppedtreebecomesbothgrotesqueandhazardous.
1237themostlastingbenefitswiththeleastdisfigurementofthetree.
Thus,itcostslessinthelongrun,andvaluablelargetreescanberetained(Fig.
12).
PruningDiseasedEvergreensAttimesitisnecessarytopruneatreetoremoveorpreventthefurtherspreadofadisease.
Undersuchcon-ditions,greatcareshouldbeexercisedsothattheprun-ingwillnotpromotethespreadofthedisease.
Deadorinfectedbranchesharborpathogensthatareeasilycarriedbycuttingtools.
Sawsandothertoolsusedinthisworkshouldbedippedinalcoholorhouseholdbleachbetweeneachcutinordertokillanypathogenwhichmightbecar-riedonthetool.
Lightlyoilallpruningtoolsafteruse.
Sanitationpruningcutsshouldbedonewellawayfrominfectedwood.
Besuretomakeyourcutinlivewoodatleast4to6inchesbelowthelastindicationofdiebackordisease.
Branchesanddebrisfromsuchpruningshouldbeburnedassoonaspossibleandasclosetothesiteascon-venienttominimizethedangerofspreadingthedisease.
Avoidpruningdiseasedtreesinwetweather.
Boththeplantsandtheairshouldbedryforseveraldaysbeforepruninganduntilthepruneddebrisisburned.
Anex-tendedperiodofdryweatherduringlatesummerisanexampleofagoodtimetoprunediseasedbranches.
Theriskofspreadingdiseasesporesthroughtoolsorthecarelesshandlingofinfectedmaterialisgreatlyde-creasedduringdryweather.
Fig.
12.
Directionalpruningcanhelpretainlargetreesnearpowerlines,butthiskindofpruningshouldbeperformedbyaprofessionaltreeservice.
WoundCareforEvergreensOpenwoundscanexposetreestounnecessarydam-agefrominsectsanddisease.
Withsimpletreatment,woundscanbeencouragedtohealrapidlyandsopro-tectvaluabletrees.
Topromoterapidhealing,trimthebarkaroundthewoundintoanellipticalshape,creatingacleanwoundedge.
Itisbesttouseasharpknifethathasbeensteril-izedwithmethylalcoholorahouseholdbleach.
Theellipticalshapearoundthewoundpreventswaterfrompoolinginthewoundandimprovesthesapflowthathealsthewound(Fig.
13).
Woundsshouldbeallowedtodryasquicklyaspossibletoavoidtheentranceofinsectsordisease.
Treedressingsandpruningpaintsdonotincreasethehealingrateofaproperlycutsurface.
Asphalttreedress-ingsarecosmetictreatmentsoftenusedonlargebasalcutstomakethetree"lookbetter.
"Anypaintusedtocoverawetwoundoronefromwhichsapisseepingmayentrapdiseaseordecay-causingfungisothatheal-ingishamperedratherthanpromoted.
Housepaintsusedonwoundswilloftenkilllivingtissue,thusenlargingthewound.
Whilemosthomegardenersbelievethattreedressingsaidhealingandpreventinfection,noevidencesupportsthistheory.
Dressingacompletelydrywoundafterthefirstgrowingseasonwouldcausenoharmtothetreeanditprobablywouldhavenobenefit.
Werec-ommend,therefore,thatyoudonotuseanytypeoftreewounddressing.
CommonConiferousEvergreenTreesFoundinIdahoThefollowinglistoftreesrepresentsthemostcom-monconiferousevergreensfoundincitiesandtownsinIdaho:Douglas-fir,Grandfir,Whitefir,Easternredcedar,Westernredcedar,Northernwhitecedar,Ponderosapine,Scotspine,Austrianpine,Westernwhitepine,RockyMountainjuniper,Albertaspruce,Norwayspruce,Coloradobluespruce,andEnglemannspruce.
Fig.
13.
Aclean-edged,ellipticalcutpromoteshealingoftreewounds.
8Issuedinfurtheranceofcooperativeextensionworkinagricultureandhomeeconomics,ActsofMay8andJune30,1914,incooperationwiththeU.
S.
DepartmentofAgriculture,LeRoyD.
Luft,DirectorofCooperativeExtensionSystem,UniversityofIdaho,Moscow,Idaho83844.
TheUniversityofIdahoprovidesequalopportunityineducationandemploymentonthebasisofrace,color,religion,nationalorigin,gender,age,disability,orstatusasaVietnam-eraveteran,asrequiredbystateandfederallaws.
AcknowledgmentThispublicationwasdeveloped,inpart,frominfor-mationsuppliedbytheUniversityofIllinois,KansasStateUniversity,andMontanaStateUniversity.
ItwaspreparedincooperationwiththeUniversityofIdahoCollegeofAgriculture,theUICollegeofForest,Wild-lifeandRangeSciences,andtheUSDACooperativeExtensionService.
AbouttheAuthorsDouglassMcConnellisaformerExtensionfor-estryassistant,RonaldMahoneyisExtensionfor-ester,andArthurD.
Partridgeisaformerprofessorofforestresources,allattheUICollegeofForest,WildlifeandRangeSciencesinMoscow.
W.
MichaelColtisExtensionhorticulturistattheUIParmaRe-searchandExtensionCenter.
Published1985;Reprinted1998$1.
50percopy