Title: St John's wort spreading accross Australian Capital Territory

St John's Wort weed[The Canberra Times 27 Nov. 2011 by Michael Inman] -- YELLOW fever is spreading across the territory, as St John's wort consolidates its grip on Canberra's grasslands. The yellow-flowering invasive weed is thriving in the capital due to the increased rainfall over the past two springs. Introduced from Europe and western Asia, St John's wort poses a high weed risk for native grasslands, grassy woodlands and grazing areas. It beats wildflowers for space, is poisonous to livestock, and may cause contact dermatitis in people, according to Territory and Municipal Services. The infestation is most obvious in sites around Red Hill, where it threatens to smother a national endangered wildflower, Rutidosis leptorrhynchoides, commonly known as the Button Wrinklewort.The ACT Parks and Conservation Service has responded by almost doubling its weed control program, to $316,500 in 2011-12. There will also be about 710 ranger hours spent controlling St John's wort. [Photo caption: "Yellow could be the colour of summer as St John's wort spreads in the ACT"]

A TAMS spokesperson said, ''St John's wort is a very persistent invasive weed which makes it difficult to control. ''Ongoing follow-up work at control sites is the only way to succeed.'' Canberrans have grown used to the purple haze of Paterson's curse over the warmer months. But TAMS said the yellow of St John's wort would be the colour of the coming summer. ''Rainfall has allowed very good grass growth which has out-competed the Paterson's curse at many areas this spring.

''Herbicide control of Paterson's curse at priority sites has also helped considerably.

''The ability of healthy perennial grass cover to out-compete Paterson's curse is one reason it has a lower weed risk of 'medium' compared to the weed risk of 'high' for St John's wort.''

TAMS said the ACT region is also having problems with the rapid spread of a number of other invasive weeds, such as blackberry, pest willows, African lovegrass, Chilean needlegrass and serrated tussock. The ACT Government has responded to this biosecurity threat by increasing weed control budgets in 2011-12.

Original source



Article: WeedsNews2637 (permalink)
Categories: :WeedsNews:weed control, :WeedsNews:community engagement
Date: 8 December 2011; 1:02:04 pm Australian Eastern Daylight Time

Author Name: David Low
Author ID: adminDavid