Sweet Reed-grass (Glyceria maxima) is a highly-invasive, exotic import from Europe and temperate Asia that has gained a foothold on the Peninsula.

An aquatic weed, it grows to over 2 m high in everything from wet soil to water up to a meter or more deep. It even can extend out over deeper water by forming floating mats with the roots connected back to the shore.

Its dense growth habit presents a threat to other aquatic life, and it has been identified as a cause of cyanide poisoning in stock.

Propagation is by seeds and pieces that spread downstream or through attachment to equipment. Once established, a single plant can generate up to 100 shoots and spreading rhizomes that form a thick mat and can spread over 30 m in just a couple of years.

Control is through a variety of means, all of which involve danger to native species. It also is easy to confuse with the native Common Reed ( Phragmites australis), so it is best to contact your Landcare Group or Melbourne Water for advice before proceeding.

– More information here, and do remember delay is not an option for early invasive species such as this.