New season weeds to watch out for
25 June 2019
With winter weather comes winter weeds, and Natural Resources South East’s NRM Officers are encouraging locals to be on the lookout.
NRM Officer Paul Wordley said there’s a range of priority declared weeds to be aware of this winter.
“Landholders should be on the lookout for horehound, Salvation Jane, false caper, and variegated thistle,” Paul said.
“One we want to bring attention to this season is variegated thistle, also known as St Mary’s thistle, milk thistle or bull thistle.”
Variegated thistle has shiny, mottled green leaves, deeply divided into toothed segments with short spines along the edges. When flowering, as early as September, flowering heads are 4-8cm, packed with purple florets to 5cm long.
“It’s really important to treat this thistle well before flowering, and continue with multiple treatments over the winter period,” Paul said.
“Seeds can remain dormant in soil for up to 9 years, however consistent and effective management of pre flowering plants can reduce years of re-emergence. Follow up is key.”
Sheep are often responsible for movement of variegated thistle seeds across pasture. Seeds can also spread by water, vehicles, machinery, or in hay, chaff, or silage.
“Variegated thistle typically establishes where there are cleared patches in pasture. We’ve been spotting it lately along fence lines, so encourage landholders to check their properties to prevent spread on to roadsides and neighbouring land.”
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.
“Preventing spread, and decreasing weeds on your property benefits industry, and most importantly the long term sustainability of your land,” Paul said.
For more information on how to identify and control weeds on your property, contact your local NRM Officer. See the link below for contact information, or call 8735 1177.
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