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

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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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