Stopping the spread of stevia ovata

REDUCING INVASIVE WEEDS

FINDING STEVIA OVATA BEFORE IT FLOWERS AND SPREADS…

11 MAY 2025

The countdown is on to find the invasive weed Stevia ovata before flowering season on the Atherton Tablelands – the time of year when its seeds spread on the wind.

Terrain NRM and Tablelands Regional Council have been working together to remove this weed, which is also known as candyleaf, from 250 hectares of land on roadsides, along powerlines, on private properties and forests in the Ravenshoe and Herberton areas.

250 hectares of control work

“Over two years, most of the known infestation areas have been treated,’’ Terrain NRM’s Evizel Seymour says.

“This weed is not as mobile as more aggressive species like Siam weed. Its seeds remain viable for only about 18 months, and it doesn’t spread easily to new areas. As a result, infestations have so far been contained to known locations.

“This presents a critical opportunity—now is the time to stay vigilant and act decisively to keep the upper hand.”

Stopping its spread on the Atherton Tablelands

Stevia ovata is currently only found on the Atherton Tablelands, in the Ravenshoe and Herbertson areas. Left uncontrolled, it can impact grazing land and natural vegetation.

“It was first found in this region in 2007. The growing season is February to May with a flowering season from the end of May through June,’’ Evizel says.

“The best time to control Stevia ovata is before it flowers. By July to August the top of the plant dies off naturally but the bottom can re-shoot with moisture and the problem continues unless it is being controlled.”

Spraying and pulling out by hand

Control work has been spraying with herbicides and pulling the weed out by hand.

Terrain NRM secured funding through the Queensland Government’s Queensland Feral Pest Initiative to follow on from earlier Stevia ovata control work by partnering with Tablelands Regional Council to work with landholders and others including Ergon Energy, Powerlink, Clean Co and the Queensland Parks and Wildlife Service.

The project also included community engagement work at events in the region, at stakeholder meetings and through the installation of two roadside signs about Stevia ovata –on Wooroora Rd and Tully Falls Rd which are in the main infestation areas.

How you can help

If you think you have Stevia ovata (candy leaf) on your property, or you have seen it in the region, or you want to know more about this invasive weed, contact Tablelands Regional Council at info@trc.qld.gov.au, by phoning 1300 362 242 or visiting the customer service centre.

STEVIA OVATA (CANDY LEAF): FAST FACTS

Native to tropical America, it was first found in Australia, on the Atherton Tablelands, in 2007. This is the only place it has been found in Australia. It’s a category 3 restricted invasive plant under the Queensland Government’s Biosecurity Act 2014.

Stevia ovata can form dense stands of vegetation, can rapidly colonise open, disturbed habitats and has potential to replace native plants and pasture.

The plant is usually 50cm-100cm tall but it can grow up to 3m tall with some plants having over 30 stems and a large, strong rootball. It has white or light pink flowers in May-June. Its leaves are arranged in mostly opposite pairs along the stem, but sometimes alternately.

It grows across a range of habitats on the Atherton Tablelands at the higher altitudes including open woodlands, native pastures and disturbed sites like roadsides and under powerlines.

Seeds can spread on the wind, in water, on machinery and animals.