Weed of Week – Coolatai Grass

In week eight of our Weed of the Week campaign, we continue to share important information on our region’s priority weeds. This week we’re looking at an emerging threat in the Snowy Monaro – Coolatai Grass.

Snowy Monaro Regional Council encourages our community to get to know our region’s unwanted (priority) weeds. Knowing what to look for and how to help, we can work together protect the environment, help our farmers and support our community.

The impact of weeds on natural vegetation can be devastating and is estimated to cost the NSW economy approximately $1.8 billion annually (NSW Department of Industry, 2018).

What is Coolatai Grass?

Coolatai grass is a long-lived, summer active perennial that grows to 1.5 metres tall and produces short rhizomes (underground stems) forming a dense grass tussock. It has greyish-green leaves that turn orangey-red in winter, particularly after frost. The leaves are harsh to touch. Leaf sheaths are usually hairless and keeled. The leaf blade is flat and 2-3 mm wide with the ligule 2-3 mm long and minutely toothed. In the Snowy Monaro Regional Council area, landholders are required to eradicate this weed if they find it on their land – land must be kept free of this weed.

Why is Coolatai Grass a problem?

Coolatai Grass easily invades relatively undisturbed ecosystems and pastures, and comes to dominate them. It is especially dangerous in areas with low ground cover (less than 70%), commonly due to heavy grazing and low soil fertility.

• It grows on a range of soils, most active on light and medium textured soils

• It is cold tolerant and grows anywhere from sea level to 1500m elevation• It easily survives hot fires, regular burning has no negative impact on plant numbers

• It quickly dominates pastures, leading to tall rank growth that: o offers low digestibility (o offers low protein (o requires feed supplementation of cattle• Seed sheds quickly on maturity

• Seeds readily stick to animal hair and wool, can survive digestion• Seeds are light and spread easily on the wind – especially by roadsides

• Poses a particular threat to fragmented native vegetation

What can you do?

• Learn to identify and effectively control Coolatai Grass• Search your property for any sign of this priority weed

• Map infestations• Remove plants, bag and burn, try to stop seed being dropped in the process

• Spot spray with a knockdown herbicide• It may be useful to sow some replacement competitive pasture species in disturbed areas to compete with new germination of Coolatai grass

• Competitive pastures (where ground cover is maintained at >70%) will resist Coolatai grass invasion• Competitive pastures in spring, maintaining high levels of ground cover over summer will resist Coolatai grass invasion

• Council’s Biosecurity officers can assist with identification and provide advice on best management practices

/Public Release. View in full here.