Flowering now, Narrow-leaf Privet is among our worst ecosystem transformer weeds, forming monoculture thickets that take over riparian vegetation in particular. For this reason, Privet patches can seem overwhelming, but they can be managed effectively by being strategic, and working from your best, most resilient areas of bush (good native canopy, diverse native vegetation) outward, picking battles you can win. Plants with flowers are very handy to target – they will take up herbicide readily, and you get to prevent the formation of new fruit and hence new seed – and the existing soil seedbank will only last a couple of years.
Depending on the site, it can be most efficient to target flowering plants first with an aim of stopping local seed production. Be cautious when killing large trees – consider the impact on canopy cover and altered light access, and be prepared to follow-up a potential sea of new Privet seedling recruits. Where you have a lot of small seedlings, spraying with a simple 1% glyphosate mix (being careful of course to avoid off-target species) can be very efficient.
Be careful hand-pulling Privet, it has a wide system of lateral roots and is easy to snap off. Either carefully dig out with a trowel, Hori knife or small pick, or try a Tree Popper – to borrow one of ours, contact Joël greatlakes@midcoast2tops.org.au or Jono inland@midcoast2tops.org.au
Cut stump herbicide application is the treatment of choice for medium sized plants – cut low and horizontal with good secateurs, a folding saw, pair of loppers (or mechanical help like a battery or petrol chainsaw if you choose to fell larger trees), and apply herbicide promptly (neat waterway-safe glyphosate with some dye, using a dripper applicator), ensuring all of the outer, living cambium layer is dosed. If lateral/buttress roots are easily accessible, these can be stem scraped to give a bigger dose and reduce the chance of reshooting. Large trees can be easily killed in-situ with stem injection using a battery powered drill with a 10mm bit, every 5-10cm around each main stem, only need to be deep enough to dose the cambium layer.
For some practical Privet killing tips, check out our video with Peter Dixon of AABR.
For more information on this weed, see NSW Weedwise
