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ThisdocumentisacompilationoftheGuidelineSpeci,icationforNurseryTreeQuality:StrategiesforGrowingaHighQualityRootSystem,Trunk,andCrowninaContainerNursery,andtheTreeCareCueCards.Ithasbeenpreparedtohelpgreenindustryprofessionalsintheeffortstoselect,plant,andcareforyoungtrees.
IllustrationsbyEdwardF.Gilman,Professor,EnvironmentalHorticultureDepartment,IFAS,UniversityofFlorida;adaptionsfromArboriculture:IntegratedManagementofLandscapeTrees,ShrubsandVines,4thed.,byR.W.Harris,J.R.Clark,andN.P.Matheny(PrenticeHall,2003).
Copyright©2011BrianKempfandEdGilman
GuidelineSpeciVicationsforSelecting,Planting,andEarlyCareofYoungTrees
NurseryTreeQuality
I. GENERALSPECIFICATIONS
ProperIdenti8ication:Alltreesshallbetruetonameasorderedorshownonplantingplansandshallbelabeledindividuallyoringroupsbyspeciesandcultivar(asappropriate).Compliance:Alltreesshallcomplywithfederalandstatelawsandregulationsrequiringinspectionforplantdisease,pests,andweeds.InspectioncertiVicatesrequiredbylawshallaccompanyeachshipmentofplants.Clearancefromthelocalcountyagriculturalcommissioner,ifrequired,shallbeobtainedbeforeplantingtreesoriginatingoutsidethecountyinwhichtheyaretobeplanted.Eventhoughtreesmayconformtocounty,state,andfederallaws,thebuyermayimposeadditionalrequirements.Inspection:ThebuyerreservestherighttorejecttreesthatdonotmeetspeciVicationsassetforthintheseguidelinesorasadoptedbythebuyer.Ifaparticulardefectorsubstandardelementcanbecorrectedeasily,appropriateremediesshallbeapplied.Ifdestructiveinspectionofarootballistobedone,thebuyerandsellershallhaveaprioragreementastothetimeandplaceofinspection,numberoftreestobeinspected,andVinancialresponsibilityfortheinspectedtrees.Delivery:ThebuyershallstipulatehowmanydayspriortodeliverythatdeliverynotiVicationisneeded.Buyershallstipulateanyspecialconsiderationstothenurserypriortoshipment.
II.HEALTHANDSTRUCTURESPECIFICATIONS
ThesespeciVicationsapplytodeciduous,broadleafevergreen,andconiferousspecies.Theydonotapplytopalms.Notethatleafcharacteristicswillnotbeevidentondeciduoustreesduringthedormantseason.
Crown:Theformanddensityofthecrownshallbetypicalforayoungspecimenofthespeciesorcultivar.Theleadershallbeintacttotheverytopofthetree.Leaves:Thesize,color,andappearanceofleavesshallbetypicalforthetimeofyearandstageofgrowthofthespeciesorcultivar.Treesshallnotshowsignsofmoisturestressasindicatedbywilted,shriveled,ordeadleaves.Branches:Shootgrowth(lengthanddiameter)throughoutthecrownshallbeappropriatefortheageandsizeofthespeciesorcultivar.Treesshallnothavedead,diseased,broken,distorted,orotherwiseinjuredbranches.Trunk:Thetreetrunkshallberelativelystraight,vertical,andfreeofwounds(exceptproperlymadepruningcuts),sunburnedareas,conks(fungalfruitingbodies),woodcracks,bleedingareas,signsofboringinsects,cankers,girdlingties,orlesions(mechanicalinjury).Theterminalbudontheleadershallbeintacttotheverytopofthetree,anditshallbethehighestpointonthetree.Roots:Therootsystemshallbesubstantiallyfreeofinjuryfrombiotic(e.g.,insectsandpathogens)andabiotic(e.g.,herbicidetoxicityandsaltinjury)agents.Rootdistributionshallbeuniformthroughoutthecontainersubstrate,andshallbeappropriateforthespeciesorcultivar.Attimeofinspectionanddelivery,therootballshallbemoistthroughout.Rootsshallnotshowsignsofexcesssoilmoistureconditionsasindicatedbystunted,discolored,distorted,ordeadroots.
Copyright©2011BrianKempfandEdGilman
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Shadetreesthatgrowtobelargeshallhaveonerelativelystraightcentralleader(Figure1).Headingthetreeisacceptableprovidedthecentralleaderisreestablishedinthenursery.
Mainbranches(Figure2)shallbewelldistributedalongthecentralleader,notclusteredtogether.Theyshallformabalancedcrownappropriateforthecultivarorspecies.
Thelargestbranchesshallbefreeofbarkinclusionsthatextendintothebranchunion(Figure4AandB).
Small‐diameterbranches(Figure5,left),particularlyontreeslessthan1inchcaliper,shouldbepresentalongthelowertrunkbelowthelowestmainbranch.Thesebranchesshallbenolargerthan3/8inchindiameter.
Desirable Notdesirable
Thediameterofbranches(Figure3)thatgrowfromthecentralleader,ortrunk,shallbenolargerthantwo‐thirds(one‐halfispreferred)thediameterofthetrunkmeasuredjustabovethebranch.
Desirable
Desirable Notdesirable
Notdesirable
DesirableDesirable Notdesirable
Figure1.
Figure2.
Figure3.
Therootcollar(theuppermostroots)(Figure7)shallbewithintheupper2inchesofthesoilmedia(substrate).Therootcollarandtheinsideportionoftherootballshallbefreeofdefects,includingcircling,kinked,andstem‐girdlingroots.Rootsatthesurfaceshouldgrowmostlystraighttothesideofthecontainer.Youmayneedtoremovesoilneartherootcollartoinspectforrootdefects.
Thetreeshallbewellrootedinthesoilmedia.Rootsshallbeuniformlydistributedthroughoutthecontainer,meaningthatrootsshouldnotbeconcentratedatthebottomoftherootball.Somerootsshouldcontactthecontainerwallinthetophalfoftherootball(Figure7,left).Whenthecontainerisremoved,therootballshallremainintact.Whenthetrunkislifted,boththetrunkandrootsystemshallmoveasone.Theimprintofthelinerorsmallercontainershallnotbevisible(Figure7,left).
Therootballshallbemoistthroughoutatthetimeofinspectionanddelivery.Therootsshallshownosignsofexcesssoilmoistureasindicatedbypoorrootgrowth,rootdiscoloration,distortion,death,orfoulodor.Thecrownshallshownosignsofmoisturestressasindicatedbywilted,shriveled,ordeadleavesorbranchdieback.
Thetrunkcaliper(diameter)andtaper(Figure6)shallbesufVicientsothatthetreeremainsverticalwithoutastake.
Thetrunkshallbefreeofwounds,sunburnedareas,conks(fungalfruitingbodies),woodcracks,bleedingareas,signsofboringinsects,cankers,orlesions.Properlymaderecentorclosedpruningcutsareacceptable.
Figure4.A
B
Figure5.
Desirable Notdesirable
NotdesirableDesirable
Figure6.
Figure7.
Desirable NotdesirableCopyright©2011BrianKempfandEdGilman3
TreePlanting
Diggingthehole:AVirm,Vlat‐bottomedholewillpreventtreesfromsinking.Digtheholeonlydeepenoughtopositiontherootcollarevenwiththelandscapesoilsurface(Figure8).Usearototillerorshoveltoloosensoilinanareathreetimesthesizeoftherootball.Thisloosesoilpromotesrapidrootgrowthandquickestablishment.
Figure8.Looseningsoilinalargeareaaroundtherootballallowsforrapidrootgrowthandquickestablishment.
B
Mulching:Alayeroforganicmulch,suchasleaflitter,shreddedbark,orwoodchips,helpsprotecttreerootsfromtemperatureextremesandconservessoilmoisture.Mulchalsohelpspreventgrassfromcompetingwiththetreeforwaterandnutrients.Themulchedareamakesiteasiertooperatemowersandweedeaterswithouthittingthetrunkandcompactingsoil.Applymulchtoadepthof3to4inches(slightlythinnerontopoftherootball)(Figure11).
Staking:Themethodofstakingisdependentonatree’sabilitytostandonitsownandthelocationoftheplantingsite.Stakingisusedtoholdtreeserect,allowtherootballtoanchor,andprotectthetrunkfromdamagebyequipment.Stakesshouldberemovedwhenthetreecanstandonitsownandtherootballisanchored.Stakesshouldbepositionedawayfromthetreeandsecuredtothetrunkatthepointwherethetreestandsstraight.Donotusewireoranystrapthatwillgirdlethetreeordamagethebark.Ifatreecannotstandstraightonitsownafterstaking,asplintstaketieddirectlytothetrunkmadeofbamboo,springsteel,oraViberglassrodmaybeusedtostraightentheuppertrunkand/orleader.Avoidusingsquarewoodsecondarystakes.
Installingthetree:Removesoilandrootsfromthetopoftherootballtoexposetherootcollar;cutawayanyrootsthatgrowoverthecollar(Figure9).Alsocutanyrootsthatcircleormatalongthesidesandbottomoftherootball(Figure10).Therootcollarshallbeevenwiththelandscapesoilafterplanting(seeFigure9).BackVillwithsoilremovedfromthehole.Minimizeairpocketsbypackinggentlyandapplyingwater.Buildaberm4inchestallaroundtherootballtohelpforcewaterthroughtherootball.Enlargethebermasthetreeestablishes.
Selectingqualitytrees:Plantingqualitytreesbeginsbyselectingtherighttreefortherightlocationandchoosingvigorous,structurallysoundtreesfromthenursery.
Figure10.Cutrootsat(A)toformnewrootsthatgrowawayfromthetrunk.Donotcutrootsat(B),sincetherootdefectswillregrow.
Figure9.Removesoilandrootsgrowingovertherootcollar(A)andplacecollarlevelwithsoilsurface(B).
Figure11.Mulchshalltapertoaslightlythinnerlayerontopoftherootball.
A AB
Figure12.Doublestaked Figure13.Doublestakedwithsplintstake.
Figure14.Singlestakedwithsplintstake.
splintstake
Copyright©2011BrianKempfandEdGilman
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Treesthatgrowtobelargearemorestructurallysoundandcost‐effectivetomaintainwhentrainedwithacentraldominantleaderthatextends30feetormoreintothecrown(Figure15,left).Vigorous,uprightbranchesandstemsthatcompetewiththecentralleadercanbecomeweaklyattached(Figure15,right).
Figure15.Goodtreestructure(left);poorstructure(right).Treeswithbranchesspacedalongthecentralleader,ortrunk(Figure15,left)arestrongerthantreeswithbranchesclusteredtogether(Figure15,right).Prunetreesatplantingtoonecentralleaderbyremovingorshortening(shown)competingstems(Figure16).Allbranchesandstemsshallbeconsiderably shorterthanthecentralleaderafterpruningiscompleted(Figure16,right).
Figure16.Shortencompetingstemstoimprovestructure.
Removeorshortenbranchesthatarelargerthanhalfthetrunkdiameteratplantingandeveryfewyearsthereafter.Shortenthembycuttingbacktoalivelateralbranch(Figure17,right).Thislateralbranchshallbepointedawayfromthetrunkanditshouldnotbegrowingupright.Thecentralleadershallbemorevisibleinthecrowncenterafterpruning.Onlylarge‐diameterbranchesneedtobeprunedbecausetheycompetewiththeleaderandcouldbeweaklyattached(Figure17,L).Smallbranches(Figure17,S)donotneedpruningbecausetheywillnotcompetewiththeleader.
Figure17.Onlylargebranchesneedpruning(L).Smallbranches(S)donotneedtobepruned.
TreeTrainingatPlantingandintheEarlyYears
Figure19.Reduceastembacktoalivelateralbranchtoslowitsgrowth.
Before
Figure18.Shorteninglargerlowbranchesconcentratesgrowthintheleaderandimprovestreestructure.
StructuralPruningChecklist1.Developandmaintainacentralleader.2.Identifythelowestbranchinwhatwillbecomethepermanentcrown.
3.Preventbranchesbelowthepermanentcrownfromgrowinglargerthanhalfthetrunkdiameter.4.Spacemainbranchesalongthecentralleader.5.Reducevigorousuprightstemsbacktolateral branchesorremoveentirely(Figure20).
Thebestwaytoshortenlargeorlongstemsandbranchesistocutthembacktoalivelateralbranch(Figure19).Thisslowsgrowthontheprunedpartsandencouragesgrowthinthedominantleadercreatingsoundstructure.
Shortenorremovethelargestlowbrancheswhenthetreeisyoungtokeepthemsmall(Figure18).Thisensuresthatonlyasmallwoundiscreatedwhentheyareeventuallyremovedfromthetrunk.
Removelargerbranchesbymakingthreecuts.Thispreventsthebarkfrompeelingorsplittingoffthetrunkbelowthecut.MaketheVinalcutbacktothebranchcollar(enlargedareaaroundunionofbranchwhereitjoinsthetrunk).
L
SS
retainthislateralbranch
livelateralbranch
After
Copyright©2011BrianKempfandEdGilman5
IrrigationConsistentirrigationiscriticalforestablishment.1.Applyabout3gallons0fwaterperinchoftrunkdiametertotherootball2or3timesperweek fortheVirstgrowingseason.2.Increasevolumeanddecreasefrequencyasthetreebecomesestablished.3.WeeklyirrigationthesecondyearandbimonthlyirrigationthethirdyearshouldbesufVicientfor establishment.4.Onceestablished,irrigationrequirementsdependonspecies,plantingsite,climate,andsoil conditions.5.Irrigationdevicesshouldberegularlycheckedforbreaksandleaks.
Copyright©2011BrianKempfandEdGilman
Reductioncutscanbeusedontreesatplantingtosubordinatebranchesthatarecodominant(Figure20).Someuprightstemsandbranchescanberemovedentirelybacktothetrunk.Headingcutsmayhavetobeusedoccasionally.
Figure 20. Before and after pruning at planting for structure
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