Weird weeds expected to arrive univited with spring rains

12 November 2020 

Landholders are urged to look out for long-forgotten weeds that might appear due to generous spring rain events across the region.

David Hughes, Senior Landscape Officer for the Northern and Yorke Landscape Board said current weather conditions were ideal for the emergence of weeds that have been missing in action during the dry spell.

“With rain replenishing our soils after a long dry period, previously dormant weed seeds are likely to take advantage of the extra moisture that’s now available,” he said. “We encourage landholders to be on high alert for weeds that haven’t troubled them for some time, as they can quickly escape and dominate farming land.”

Two pest plants with huge potential to cause headaches for landholders in the Northern and Yorke region are African Rue (Peganum harmala) and Creeping Knapweed (Acroptilon repens).

“Both have extensive root systems that make them very difficult to control once established,” said Mr Hughes. “The end result is an expensive problem that can devalue your property.”

African Rue is a small, white-flowered shrub that is unpalatable to stock and competes with pastures for moisture and nutrients. A 2005 study showed that African Rue has the ability to invade up to 73% of the land area in our region.

One of the most competitive weeds, Creeping Knapweed is known to reduce cereal crop yields by 75%. It forms large, dense single-species stands and removes vital moisture and nutrients over summer.

Root fragments broken off during cultivation is a major cause of spread of both these problem weeds.

If you discover a weird weed on your property, contact your local Landscape Officer to help identify it. It could be an odd pest plant or a rare native, so it’s best to confirm the species first. Call the Northern and Yorke Landscape Board on 8841 3400 or email ny.landscapeboard@sa.gov.au.


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