With winter weather comes winter weeds and the Limestone Coast Landscape Board is encouraging landholders to be on the lookout.
Limestone Coast Landscape Board southern operations team leader Nicole McGuiness said there was a range of priority declared weeds to be aware of this winter.
“Landholders should be looking to control declared weeds such as Salvation Jane, Horehound, African boxthorn and Variegated thistle,” she said.
“Preventing spread and decreasing weeds on your property benefits industry and most importantly the long-term sustainability of your land.”
Early intervention and control of winter weeds can reduce control costs significantly as the young, emerging plants require less herbicide. This also allows desirable pasture species to thrive and out compete weed species.
Ms McGuiness said a priority weed for the LC Landscape Board this season was variegated thistle.
“Variegated thistle typically establishes where there are bare patches in pasture and with dry summer conditions, these paddocks are more prone to new weed infestations,” she said.
“Variegated thistle has shiny, mottled green leaves, deeply divided into toothed segments with short spines along the edges. Variegated thistle accumulates nitrate throughout its growth period, to levels that can be toxic to sheep. The weed becomes most palatable when it has wilted, this is also when nitrate levels are most dangerous.
“It’s really important to treat this thistle well before it flowers in spring and with multiple treatments over the winter period.
“Seeds can remain dormant in soil for up to nine years, however consistent and effective management of pre flowering plants can reduce years of re-emergence. Follow up control is key.”
Ms McGuiness said sheep were often responsible for movement of variegated thistle seeds across pasture. Seeds can also spread by water, vehicles, machinery, or in hay, chaff, or silage.
Landholders are encouraged to check their properties in particular along fence lines to prevent spread on to roadsides and neighbouring land.
“Declared weeds do not recognise property boundaries. By working together we have the best chance of controlling priority pest plants in the region,” she said.
Landholders have a legal responsibility, under the Landscape South Australia Act 2019, to control declared plants on their land.
