It was once a popular garden plant, but now the evergreen herb is causing considerable problems in parts of Australia.
In fact, the Weed Wise website says the asparagus fern (Asparagus aethiopicus) is “one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts.”
Is asparagus fern a weed?
Despite its misleading name, asparagus fern is not a vegetable or a true fern – it’s an aggressive pest, as Jenny Dillon, the gardening editor at Better Homes and Gardens, clarifies.
“Originally from Africa, it was introduced to Australia as an ornamental, but quickly became invasive, especially in our iconic and unique bushlands in Queensland and NSW where it smothers ground covers and understorey plants,” says Jenny.
“Underground, the roots can form dense mats that prevent the growth of native seedlings.”
What does the asparagus fern look like?
Jenny adds, “Seven species of asparagus ferns have been declared Weeds of National Significance (WoNS). They can still be found growing in the gardens of older homes, but nowadays, you can’t sell them, give them away, or release them into the environment.”
Among these offenders, the basket asparagus fern (Asparagus aethiopicus cv. Sprengeri) is notorious for escaping garden beds.
Here’s what to look out for:
- Foliage: The fern-like foliage consists of numerous delicate, needle-like leaflets called cladophylls. These cladophylls are arranged in clusters along wiry stems.
- Stems: The stems feature woody and wiry stems.
- Berries: In late summer to early autumn, the plant produces small, round berries that start green and turn red as they mature. These berries contain seeds, which birds and other animals spread.
- Roots: Asparagus fern has rhizomatous roots, which are underground stems that spread horizontally.
- Size: Asparagus ferns range from small, compact plants to large, sprawling masses covering several square metres.
How does asparagus fern spread?
Asparagus fern thrives in regions with mild, frost-free climates. While it can tolerate some sun, it prefers growing in shaded or partially shaded areas. Asparagus fern likes moist soil and can tolerate occasional flooding. It often grows near water sources such as rivers, streams, or wetlands. However, once established, it can also tolerate periods of drought.
Asparagus fern spreads in Australia mainly through its ability to produce berries containing seeds.
“It produces masses of tiny red, orange, or purply-black berries – depending on the species – eaten by birds, reptiles, and foxes, and the seeds are then released with their droppings,” says Jenny.
Additionally, the plant can also spread underground through its rhizomatous roots.
Not disposing of the plant properly can also cause it to spread, as discarded plant material can take root and establish new plants.
How to kill asparagus fern:
- Manual removal: For small infestations, manually digging up the plants, including their roots, can be effective. The plant will grow back if you don’t remove the entire root system. Dispose of the plant material carefully to avoid spreading seeds or rhizomes to other areas.
- Chemical control: Herbicides can kill asparagus fern, but be cautious as they can harm other plants if not applied carefully. Follow the manufacturer’s instructions regarding application rates and safety precautions. A reapplication is likely necessary.
- The asparagus assassin: Queensland man Ron Gooch has invented a tool, he calls the “asparagus assassin”, to fight the spread of the invasive asparagus fern. Ron told the ABC News, “I’ve taken out thousands of them with it.”
Related content:
The lavender species gardeners need to stop planting
Related stories
Native ad body.
Native ad body.
Native ad body.
