GuidelineSpeci,icationsforNurseryTreeQuality

Revision 2009

BACKGROUND

ThisdocumentisarevisionofapreviouspublicationentitledGuidelineSpeci,icationsforNurseryTreeQuality,publishedbytheUrbanTreeFoundation,whichwasdevelopedbyacommitteeofhorticultureprofessionalsfromthenursery,landscape,municipal,consulting,andacademicsectors.TheoriginalpublicationhasbeenpostedonlineattheFoundation'sWebsite(http://www.urbantree.org/specs.asp)since2002andhasbeenusedbypublic,private,andnonpro,itgroupstoselectandspecifyqualitynurserytrees.Recommendationsforimprovementstothedocumentreceivedinthepast5yearshavebeenincorporatedinthis2009revision.

ThefollowingpeopleworkedontheoriginalGuidelineSpeci,icationsforNurseryTreeQuality:

DavidBurger,UCDavisDepartmentofPlantSciencesBarrieCoate,ConsultingArborist,LosGatosLarryCostello,UCCooperativeExtension,HalfMoonBayRobertCrudup,ValleyCrestTreeCompany,SunolJimGeiger,USForestService,Paci,icSouthWestRegionBruceHagen,CaliforniaDepartmentofForestryandFireProtection,SantaRosa,RetiredRichardHarris,ProfessorEmeritus,UCDavisDepartmentofPlantSciencesBrianKempf,UrbanTreeFoundation,VisaliaJerryKoch,CityofBerkeleyDivisionofUrbanForestry,RetiredBobLudekens,L.E.CookeCompany,VisaliaGregMcPherson,USForestService,PSWResearchStation,CenterforUrbanForestResearchMarthaOzonoff,CaliforniaReLeaf,DavisEdPerry,UCCooperativeExtension,StanislausCountyMarkioRobert,CaltransLDAMaintenanceDivision,Oakland

IllustrationsbyEdwardF.Gilman,Professor,EnvironmentalHorticultureDepartment,IFAS,UniversityofFlorida.AdaptionsfromArboriculture:IntegratedManagementofLandscapeTrees,ShrubsandVines,4thed.,byR.W.Harris,J.R.Clark,andN.P.Matheny(PrenticeHall,2003).

Copyright©2009BrianKempf

UrbanTreeFoundation115S.DollnerAve.Visalia,Ca93291www.urbantree.orgbrian@urbantree.org

Introduction

Thisdocumentprovidesspeci,icationsforselectingandspecifyingqualitynurserytreesinCalifornia,withafocusoncontainerstock.Keytraitsofnurserytreesareidenti,iedanddescribedtoprovidegrowersandbuyerswiththeinformationtheyneedtodistinguishgood‐qualitystockfrompoor‐qualitystock.Structuralandhealthcharacteristicsaredescribed,aswellaslabeling,compliancewithlawsandregulations,andinspectionofnurserystock.Ifaparticulardefectorsubstandardelementcanbecorrectedeasily,appropriateremediesshouldbeappliedasagreeduponbybothparties.I. GENERALSPECIFICATIONS

A.ProperIdenti>ication:Alltreesshallbetruetonameasorderedorshownonplantingplansandshallbelabeledindividuallyoringroupsbyspeciesandcultivar(asappropriate).B.Compliance:Alltreesshallcomplywithfederalandstatelawsandregulationsrequiringinspectionforplantdisease,pests,andweeds.Inspectioncerti,icatesrequiredbylawshallaccompanyeachshipmentofplants.Clearancefromthelocalcountyagriculturalcommissioner,ifrequired,shallbeobtainedbeforeplantingtreesoriginatingoutsidethecountyinwhichtheyaretobeplanted.Eventhoughtreesmayconformtocounty,state,andfederallaws,thebuyermayimposeadditionalrequirements.C.Inspection:Thebuyerreservestherighttorejecttreesthatdonotmeetspeci,icationsassetforthintheseguidelinesorasadoptedbythebuyer.Ifaparticulardefectorsubstandardelementcanbecorrectedeasily,appropriateremediesshallbeapplied.Ifdestructiveinspectionofarootballistobedone,thebuyerandsellershouldhaveaprioragreementastothetimeandplaceofinspection,numberoftreestobeinspected,and,inancialresponsibilityfortheinspectedtrees.D.Delivery:Thebuyershallstipulatehowmanydayspriortodeliverythatdeliverynoti,icationisneeded.Buyershallstipulateanyspecialconsiderationstothenurserypriortoshipment.

II.HEALTHANDSTRUCTURESPECIFICATIONS

Thesespeci,icationsapplytodeciduous,broadleafevergreen,andconiferousspecies.Theydonotapplytopalms.Notethatleafcharacteristicswillnotbeevidentondeciduoustreesduringthedormantseason.

A.TreeHealth

1.Crown:Theformanddensityofthecrownshallbetypicalforayoungspecimenofthespeciesorcultivar.Changesinformcausedbywind,pruningpractices,pests,orotherfactorsshallnotsubstantiallyaltertheformforthespeciesorcultivar.2.Leaves:Thesize,color,andappearanceofleavesshallbetypicalforthetimeofyearandstageofgrowthofthespeciesorcultivar.Treesshallnotshowsignsofprolongedmoisturestressasindicatedbywilted,shriveled,ordeadleaves.3.Branches:Shootgrowth(lengthanddiameter)throughoutthecrownshouldbeappropriatefortheageandsizeofthespeciesorcultivar.Treesshallnothavedead,diseased,broken,distorted,orotherwiseinjuredbranches.

4.Trunk:Thetreetrunkshallberelativelystraight,vertical,andfreeofwounds(exceptproperlymadepruningcuts),sunburnedareas,conks(fungalfruitingbodies),woodcracks,bleedingareas,signsofboringinsects,galls,cankers,girdlingties,orlesions(mechanicalinjury).

5.Roots:Therootsystemshallbesubstantiallyfreeofinjuryfrombiotic(e.g.,insectsandpathogens)andabiotic(e.g.,herbicidetoxicityandsaltinjury)agents.Rootdistributionshallbeuniformthroughoutthecontainersubstrate,andgrowthshallbeappropriateforthespeciesorcultivar.Attimeofinspectionanddelivery,therootballshallbemoistthroughout.Rootsshallnotshowsignsofexcesssoilmoistureconditionsasindicatedbystunted,discolored,distorted,ordeadroots.

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B. TreeCrown

Note:Crownspeci,icationsdonotapplytoplantsthathavebeenspeci,icallytrainedinthenurseryastopiary,espalier,multistem,clump,oruniqueselectionssuchascontortedorweepingcultivars.1.Treesshallhaveasingle,relativelystraightcentralleader.Theyshallbefreeofcodominantstemsandvigorous,uprightbranchesthatcompetewiththecentralleader.Iftheoriginalleaderhasbeenheaded,anewleaderatleastone‐halfofthediameteroftheoriginalleadershallbepresent.

Nottoppingisdesirable.

Toppingandretainingaleaderisdesirable.

Toppingwithoutretainingaleaderisnotdesirable.

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2.Mainbranchesshallbewelldistributedalongthecentralleadernotclusteredtogether.Theyshallformabalancedcrownappropriateforthecultivar/species.

NotDesirableDesirable

3.Branchdiametershallbenolargerthantwo‐thirds(one‐halfispreferred)thediameterofthecentralleadermeasured1inchabovethebranch.

Desirable NotDesirable

4.Theattachmentofthelargestbranches(scaffoldbranches)shallbefreeofincludedbark.

Desirable NotDesirable

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5.Temporarybranches,unlessotherwisespeci,ied,shouldbepresentalongthelowertrunkbelowthelowestmain(scaffold)branch,particularlyfortreeslessthan1inchincaliper.Thesebranchesshouldbenogreaterthan3/8inchdiameter.Cleartrunkshouldbenomorethan40%ofthetotalheightofthetree.

NotDesirableDesirable

C.Trunk1.Thetrunkshallbefreeofwounds(exceptproperly‐madepruningcuts),sunburnedareas,conks(fungalfruiting‐bodies),woodcracks,bleedingareas,signsofboringinsects,galls,cankersand/orlesions.

2.Trunkcaliperandtapershallbesuf,icientsothatthetreewillremainverticalwithoutastake.Trunkcaliperat6inchesabovethesoilmedia(substrate)surfaceshallbewithinthediameterrangeshownforeachcontainersizebelow:ContainerSize‐‐‐‐‐‐‐TrunkDiameter#5.............................0.5"to0.75"#15..........................0.75"to1.5"24‐inchbox...........1.5"to2.5"

NotDesirableDesirable

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D. Roots1. Theuppermostrootsorrootcollar(rootcrown)shallbewithintheupper2inchesofthesoilmedia(substrate).

2.Therootcollarandtheinsideportionoftherootballshallbefreeofdefects,includingcircling,kinked,andstemgirdlingroots.Soilremovalneartherootcollarmaybenecessarytoinspecttheaforementionedrootdefects.

4.Thetreeshallbewellrootedinthesoilmedia(substrate).Rootdistributionshallbeuniformthroughoutthecontainermedia.Structureandgrowthshallbeappropriateforthespecies/cultivar.Whenthecontainerisremoved,therootballshallremainintact.Whenthetrunkisliftedboththetrunkandrootsystemshallmoveasone.5.Atthetimeofinspectionanddelivery,therootballshallbemoistthroughout.Thecrownshallshownosignsofmoisturestressasindicatedbywilted,shriveled,ordeadleavesorbranchdieback.Therootsshallshownosignsofexcesssoilmoistureasindicatedbypoorrootgrowth,rootdiscoloration,distortion,death,orfoulodor.III.INSPECTION

Thebuyerreservestherighttorejecttreesthatdonotmeetspeci,icationsassetforthintheseguidelinesorasadoptedbythebuyer.Ifaparticulardefectorsubstandardelementorcharacteristiccanbeeasilycorrected,appropriateremediesareencouraged.Ifdestructiveinspectionofarootballorballsistobedone,thebuyerandsellershouldhaveaprioragreementastothetimeandplaceofinspection,minimumnumberoftreestobeinspectedorpercentageofaspeciesorcultivar,and,inancialresponsibilityfortheinspectedtrees.VI.DELIVERY

Thebuyershouldstipulatehowmanydayspriortodeliverythatnoti,icationisneeded.

Desirable NotDesirable3.Rootsontheperipheryandbottomoftherootballshallbelessthan1/4inchindiameter(1/8inchispreferred).Themaximumacceptablerootdiameterontheperipheryshouldbeindicated.

Desirable NotDesirable

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GLOSSARY:caliper.Trunkdiametermeasured6inchesfromtheground;ifcaliperisgreaterthan4inches,thecalipermeasurementistakenat12inchesfromtheground.central leader. A continuation of the main trunk located more or less in the center of the crown, beginning at the lowest main branch (scaffold) and extending to the top of the tree. Also referred to as the dominant leader.

circling roots. One or more roots whose diameter is greater than 10% of the trunk caliper circling more than one-third of the trunk.cleartrunk.Theportionofthetrunkbelowthecrownlackinglateralbranches;thisincludestheportionofthetrunkwithshortenedtemporarybranchesthatarebelowthemaincrown.codominant. Two or more vigorous, upright branches or stems of relatively equal size that originate from a common point, usually where the leader was lost or removed.crown. The portion of a tree beginning at the lowest main (scaffold) branch extending to the top of the tree.cultivar. A named plant selection from which identical or nearly identical plants can be produced, usually by vegetative propagation or cloning.included bark. Bark embedded in the union between a branch and the trunk or between two or more stems that prevents the formation of a normal branch bark ridge.kinked root. A main mother root that is sharply bent.leader.Thedominantstemthatusuallydevelopsintothemaintrunk.photosynthate. Sugar and other carbohydrates that are produced by the foliage and stems during photosynthesis.root collar. The base of a tree where the main roots and trunk meet. Also referred to as the root flare.scaffold branches. Large main branches that form the main structure of the crown.stem-girdling root. A circling, bent, or straight root that touches or rests on the trunk or root flare that can become a permanent root.temporary branch. A small branch that is temporarily retained along the lower trunk of young trees.trunk. The main stem of a tree, beginning at the root collar and ending at the lowest main scaffold branch.taper. The thickening of a trunk or branch toward its base.

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