Pretty Flowering Plants That Are Classified Weeds in Parts of Australia

Pretty Flowering Plants That Are Classified Weeds in Parts of Australia

There’s always the temptation as a gardener or slow flower farmer to use pretty weeds growing wild on your property in floral arrangements, and especially if the growing season is coming to an end and you don’t have much on hand to fill vases or bouquets.

As a responsible flower grower however, it’s important to check with local and state authorities that the wild plants you want to harvest, or even the flower varieties that you want to grow, aren’t in fact classified as environmental or noxious weeds.

Here’s a list of some pretty plants that are classified weeds in regions and states across Australia so you know what to avoid growing, selling and distributing:

Pampas Grass

Instagram is single-handedly responsible for the demand in pampas. With its creamy-white foliage, 6-feet tall feathery heads, the plant is highly popular with wedding event stylists, floral designers and Instagrammers alike. In many parts of New South Wales and Queensland, however, Pampas Grass is actually classified as a noxious weed and is banned from sale and distribution. Pampas Grass flower heads can produce up to 100,000 seeds that spread prolifically with the wind. Australian biosecurity officers will seize these illegal plants from florists so if you live in these regions and adore the plant’s appearance but don’t want to commit an environmental offence, wild millet is a great alternative – and it’s legal.

Pampas grass may be beautiful but it’s also a classified weed in some Australian states. Photo: Maria Velniceriu.

Ageratum (Ageratum houstonianum and Ageratum conyzoides)

A popular species of cut flower originally from tropical America, Ageratum are used as filler flowers in many floral bouquets. With its green leaves and soft, fluffy lilac-blue coloured flowers, it’s easy to see why its a favourite amongst growers and florists. While many find this plant attractive, in Queensland and New South Wales, this introduced species and more specifically the Ageratum houstonianum and Ageratum conyzoides varieties commonly known as billygoat weed, have become invasive. Taking over paddocks and competing with native flora for space, Ageratum flowers all year round making it especially hard to eradicate. Classified as an environmental weed in both states, it has also been found to be toxic to horses.

Arum Lily

A visually spectacular plant native to South Africa and traditionally used in funeral arrangements, the arum lily, also known as calla lily, has been declared an environmental weed in Western Australia for its ability to invade bushland and outcompete native plant species. Its sale is highly prohibited in the state; growers and sellers found to be distributing the plant can face heavy penalties. Originally introduced as a garden plant, the arum lily is now widespread and usually found in wet, swampy areas. The invasive species also has the potential to kill livestock.

Arum lilies are regarded as an environmental pest in Western Australia. Photo: Nature Uninterrupted Photography.

Easter Cassia

This gorgeous shrub native to the tropical Americas produces spectacular clusters of yellow flowers during Spring and Summer and its papery seed pod distributes seeds easily. While widely naturalised across many parts of Australia, this plant is classified as a weed in many Australian states. In Queensland, the weed is a ‘category 3’ weed which means it must not be distributed, disposed or released into the environment without permit.


With its luscious succulent-like leaves and a tall blue or white flowering head, the Agapanthus is truly breathtaking in the summer months as it puts on a showy display. Native to South Africa, the plant is well adapted to the Australian climate, a little too adapted in some regions, and as a result, it is declared an environmental weed species in some council areas of Victoria such as the Mornington Peninsula. Its ability to spread and dominate native plants is a common concern of Aussie flower growers so it’s best to check with local laws to ensure that you aren’t spreading a known weed in your corner of Australia.

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Pretty Flowering Plants That Are Classified Weeds in Parts of Australia

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Cover image of woman standing near pampas grass by Mathilde Langevin.

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