Asparagus weeds (Asparagus species) are some of the most abundant environmental weeds on the mid north coast. Unlike their edible cousin, these plants readily invade coastal bushland areas causing significant loss of native plant diversity and robbing the ground of moisture.
Asparagus fern, Foxtail fern, Climbing asparagus fern, Bridal creeper, Ground asparagus, Ming asparagus and Sicklethorn are all present in our region. Ground asparagus is a weed of national significance and many of the other species are listed as key threatening processes to the survival of threatened native plants.
Introduced from Africa
Asparagus weeds are native to Africa and were introduced to Australia as ornamental plants. Though fern-like in appearance, they are perennial plants that form small white flowers followed by green berries that turn orange, red or black when mature. These berries are spread by birds throughout bushland and gardens. Asparagus weeds are also spread via garden waste dumping.
Common features across species
Though each species differs in appearance, they share a number of common features such as:
- strong wiry stems that often have sharp spines. On some species a number of stems will grow from a single woody crown.
- fine, feathery or narrow “leaves” that are actually modified stems called cladodes.
- small white, star-shaped flowers that form clusters of berries.
- white, watery tubers that form along the roots. These tubers do not regenerate if left in the soil as they are only for water and energy storage.
Eradication is challenging
Asparagus weeds are very persistent and difficult to eradicate. If digging plants out, take care to remove the central woody crown. A knife or small saw can be used to cut the roots off around the crown. Any herbicide treatment should add a penetrant to the mix as the waxy stems can repel most herbicides.