Weed Wattles

Weed Wattles

Acacia Species

NottobeconfusedwithourownGoldenWreathWattle(AcaciaSaligna),EasternStates WattleshavebecomeproblematicintheSouthWestduetotheirpreviouspopularityas ornamentaltrees&assoilstabilisers.Theseinclude:

SydneyGoldenWattle(A longifolia)

FlindersRangeWattle(A.iteaphylla)

CootamundraWattle(A.baileyana)

SilverWattle(A dealbata)

QueenslandSilverWattle(A.podalyriifolia)

GoldenWattle(A.pycnantha)

The Problem / Impact

WeedWattlesarenotaproblemintheirownnatural geographiclocationswherelocalseed-eatinginsects keepthemincheck.Butthisnaturalcontroldoesnot occurinWesternAustraliawherethesewattles reproduceprolifically byseed.

TheImpactofWeedWattles: INCREASEDBUSHFIRETHREAT:Wattlesarenitrogen fixers.Whentheygrowinanareathathasbeen disturbedthecombination ofdisturbedsoilandextra nitrogenencouragesexoticgrassestoinvade.Asthegrassesdryoutinsummer,theyincrease theriskofbushfire.Firestimulatesmorewattleseedstogerminateandadestructivecycleisset inmotion.

OUTCOMPETENATIVESPECIES:underoptimumconditionscan formdense,almostimpenetrable thicketsoftreeseffectivelywipingoutallothernativeplantsandhabitatfornativeanimals.

Growth Habit & Biological Weak Link

Perennial,treesorspreadingshrubsupto8mhigh(variety dependent).ThemainfloweringperiodisJunetoOctober. Seedlingsgerminateinwinterproducingacaciatypejuvenile leavesforthefirstseasonortwo.

Thejuvenilesquicklygrowtomaturityandbecomeprolific producersofpodsandseedsin2-3years.Thicketsareoften formedandfewspeciesgrowintheunderstorey.

Aweedwattle'sbiologicalweaklinkispriortoflowering (matureplants)&atseedlingstage.Treesaremosteffectively controlledusingherbicidesbetweenMarchandAugust.Itis importantthatfelledtreesandbranchesareremovedasthey canreproducevegetativelybydevelopingadventurousroots wheretheplantmeetsthesoil.

Management & Control Options

SEEDLINGS:

Wattlesarebestcontrolledasseedlingswhentheyareeasytoleverandhand‐pullorover‐spraywitha10%solutionglyphosate. Asseedmayremaindormantformorethan10years,annualfollowupcontrolofnewly emergedseedlingsisessential.

MATUREPLANTS:

Pruningtheflowersbeforetheysetseedisnotapracticaloptiononcethesewattlesreacha certainsize Theonlysurewaytopreventseedspreadingistofellthetreeandthenpainting thefreshlycutstumpwithasolutionof50%glyphosatetopreventsuckeringandregrowth oftheplant

Alternatively,treescanbepoisonedandkilledwithoutfellingbyinjectingthemwitha50% glyphosatesolution,orbypaintingthebarkaroundthebaseofthetreewitha250mlmixof Access®in15Lofdiesel

Rehabilitation & Prevention

Youcanhelpbyreplacingpotentialweedwattlesgrowingonyour propertywithnativetreesorwithotherspeciesthathaveless potentialtobecomeweedsinnativebushland. Areasthathavebeen clearedofweedwattlesneedtoberevegetatedassoonaspracticably possibletooutcompeteanygerminatingseedsthatmaybeleft behind.Tryplantingourownnativewattleinstead-GoldenWreath Wattle(AcaciaSaligna).

References & Further Information

SourcesofInformationforthisflier: HerbiGuidewww.herbiguide.com.au-Detailedinformationaboutweedspeciesandcontrolmethods. FactSheet–WeedWattles,TheCityofBunbury DPIRDWebsite:https://www.agric.wa.gov.au/declared-plants/acacia-declared-pest FurtherReading: Moore,J&Wheeler,J(2019)SouthernWeedsandtheircontrol DepartmentofAgricultureandFoodWA