Quick Facts

Quick facts

• Originally from South Africa, Bridal Veil (Asparagus declinatus), a Weed of National Significance, is a weakly climbing herb that has become a highly invasive and aggressive environmental weed in cool temperate areas.
• It is presently confined to a few areas in South Australia and Western Australia, but has the potential to spread and become a more serious weed, similar to its relative Bridal Creeper (Asparagus asparagoides).
• It is spread by seeds, mainly by birds who eat the fruits dispersing viable seeds in dropping up to 10 kilometres away, and can establish in pristine native vegetation.
• Bridal Veil has a mass of above ground stems with narrow waxy foliage that smothers the ground and smaller shrub layer. 
• Produces a profusion of below ground rhizomes and tubers which suppresses other ground flora, reducing available soil moisture and nutrients, preventing the re-establishment of desirable species.
• The extensive root system and prolific seed production makes control difficult requiring very long-term commitment over decades, with repeated control action and monitoring requiring an integrated management strategy.
• Control options include; chemical with a variety of application options; non-chemical including, mechanical, hand pulling, that removes the underground rhizome to kill plant.
• All control programs should aim to reduce the amount of seed produced, with prevention the most cost-effective form of weed control.
• No biological control agent is presently active for Bridal Veil.

What Does It Look Like?

What is it?

Bridal Veil (Asparagus declinatus) is a delicate much-branched scrambler or weak climbing plant to 1 m high, with branches sometimes up to 3 m long, and an extensive perennial (long-lived) underground root system of branching rhizomes (underground, horizontal stems), bearing numerous tubers (storage organs). The above ground portion of the plant dies back during summer and reappears with autumn rains while the underground parts remain dormant.

The "leaves", called cladodes are not true leaves but flattened stems that look and function like leaves. Cladodes arise from the base of the true leaves, which are reduced to scales. The leaf-like cladodes are blue-green, finely slender, needle-shaped, produced in 3s at each node along the stem, are all more or less equal in length being 3–9 mm long, c. 0.5 mm wide.

The root system forms dense underground clumps of underground mats (Parsons & Cuthbertson 1992; Vivian-Smith & Grimshaw 2006). The below ground mats are rhizomes (underground stems or potential growing points) attached to fleshy tubers (storage organs). The clumps of underground stems are capable of vegetative reproduction, producing new stems and plants if the above ground (stems and leaves) are removed or die back in unfavourable conditions, like a bulb does. The main roots supply water and nutrients to the plant, and swollen fleshy white tubers only act as an underground storage systems for the plant.  Neither roots or tubers are not capable of producing new stems or plants. However, if the tubers are attached to rhizomes, the rhizomes can grow into new plants with the tubers acting as energy for the new plant. The tubers help the plant survive in harsh unfavourable growing conditions over long periods of time. Tubers are roughly ovoid in shape and large.

The flowers are white to greenish white, bisexual (with male and female parts in one flower), and solitary in axils (occur individually in 'leaf stalk), with a short flower tube to 1.5 mm long, stamens Male reproductive organs) are shorter than the perianth (flower).

The fruit is an ovoid berry about 12 mm long, pale bluish-grey to whitish to light green semi-translucent berry, normally containing 3-8 seeds (Navie 2004; Lawrie 2006), Seeds 3–9, 2.5–3.5 mm long. 

Recognition: This species can normally be recognised by the combination of the following characters;  Soft leaves (cldodes) in 3s 3-9 mm long; green ripe fruit.

For further information and assistance with identification of Bridal Veil contact the herbarium in your state or territory.

Flower colour

White to greenish white.

Growth form (weed type/habit)

Herb, Vine

Where it currently grows? Preferred habitat

Bridal Veil has infested roadside, native vegetation, rocky outcrops, pine forest and is strongly correlated with canopy cover (Lawrie undated) which presumably supplies shelter from the hot sun. It can grow with other Asparagus weeds in these environments.

Are there similar species?

Bridal Veil is characterised by its climbing habit, having 3 needle-like cladodes per axil, bisexual flowers and bluish grey to whitish to pale green fruit. In Australia it is most likely to be confused with other species of Asparagus with fine needle-like cladodes about 0.5 mm wide, such as Asparagus africanus, A. officinalis, A. plumosus, A. racemosus and A. virgatus. The fruit colour and the number of cladodes per axil are two ways of distinguishing the species.

Asparagus africanus has numerous cladodes per axil and orange fruit, Asparagus officinalis is an erect herb, has unisexual flowers and red fruit, A. plumosus has numerous cladodes per axil and black fruit, A. racemosus has 3-6 cladodes per axil and red fruit and A. virgatus has 3 cladodes per axil and orange fruit.

Bridal Veil may also be confused with A. aethiopicus which has flattened (not needle-like) narrow cladodes 2-3 mm wide and red fruit (see Navie 2004).

Why Is It A Weed?

What are its impacts?

Bridal Veil (Asparagus declinatus) is a Weed of National Significance (WONS). It is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts (CRC 2003). it is an invasive soft herb or vine that forms dense impenetrable thickets excluding desirable species. 

Agriculture: Bridal Veil (Asparagus declinatus) is not known or reported as a problematic agricultural weed. 

Native ecosystems:  Bridal Veil (Asparagus declinatus) is a highly invasive environmental weed and unlike most environmental weeds can establish in undisturbed native vegetation. The climbing stems form a dense canopy which smothers other vegetation, Bridal Veil is an invasive and aggressive environmental weed that produces thick tuberous root masses and dense foliage that smothers and out-competes the surrounding native vegetation. It forms a dense, underground, tuberous root mass that prevents native plant recruitment and regeneration (Lawrie 2006), reducing available soil moisture and nutrients, impacting on native animals. The underground well developed rhizomes and numerous tubers allow the plant to tolerate dry periods. It colonises and dominates both the shrub and herb levels, leading to displacement of native vegetation in native systems including rocky outcrops, various woodlands, and coastal habitats.

Urban areas: Bridal Veil (Asparagus declinatus) grows on urban fringes and edges, on abandoned or degraded land, that further spread beyond in to native vegetation.

How does it spread?

Bridal Veil is a heavy producer of fruit (100-800 fruit/m²). The fruit is known to be dispersed by birds, with some of the larger birds capable of carrying the seed a distance of 10 km from the source. There is also potential for some ground dwelling animals to disperse the seed (Lawrie undated). Movement of soil containing roots and tubers (e.g. by grading) could be another potential source for the spread of plants.

What is its history in Australia?

Bridal Veil was introduced into Australia as an ornamental plant and was first recorded as a garden plant in 1870. The first naturalised occurrence of Bridal Veil in South Australia was recorded on Kangaroo Island in 1954. On the mainland, it was first recorded in 1966 near Victor Harbor and has since increased its range dramatically (Lawrie 2006).

How To Manage It?

Best practice management

Control of Bridal Veil (Asparagus declinatus) is possible by chemical and mechanical means. Other less common control methods include grazing and fire. Grazing by cattle and sheep can successfully keep Bridal Veil at low levels and prevent fruit production. Biological control options are not available for Bridal Veil.

Chemical control: Applying herbicide is the most common method of controlling Bridal Veil. Herbicide is most effective when sprayed during the winter to early spring flowering period when plants are actively growing. However, leaves of Bridal Veil are fine and waxy which can make herbicide application difficult, as the chemicals do not adhere to the leaves very well. Trials by the Kangaroo Island Asparagus Weeds Committee have shown that emulsifiable vegetable oil mixed with the herbicide will help the chemicals to stick (Lawrie 2006).

However, because Bridal Veil often grows in areas of native vegetation, it is particularly important to avoid contact with desirable plants or soil near tree root zones. Isolated plants can be treated with a recommended herbicide applied by spot spraying. As infestations become larger, a strategically staged approach for removal is advisable to ensure that treated areas are not re-infested (CRC 2003). Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au .

Non-chemical control: Physical control: Physical removal of Bridal Veil involves carefully excavating around and under the tuberous root mass and then levering it out with hand tools. This control method is only effective if all of the tuberous root mass, including the rhizomes, are dug up and removed from the site (Lawrie 2006). This may be possible for new, small infestations or as a follow-up after several years of herbicide control of a larger infestation. Slashing the stems and leaves may prevent fruit production and slowly deplete root reserves but it will not eradicate an infestation (CRC 2003). Small infestations can be controlled by hand pulling where practical.

Hand pulling can only be used for small plants and infestation. The rhizomes (main growing points at the top of the soil where the stem emerge) should be removed when hand pulling.  If the plant breaks leaving any or all the rhizome, plants will immediately regrow if conditions allow. 

Mechanical control: However, for large dense infestations where little to no native plants remain mechanical removal of above ground parts parts may help.

Competition and management: Grazing can provide some control. Sheep will graze on the new shoots and are more likely to chew it down than cattle. However, Bridal Veil is not a preferred food source for sheep and cattle and so grazing should be considered as an opportunistic control method and not relied upon to eradicate an infestation (Lawrie 2006).

Disposal: When removing material off-site, rhizomes can regrow and re-shoot if not killed. Any rhizomes that come in to contact with the ground, on or off site, will re-shoot. Material can be composted or solarised and the same methods should be used for the fruits containing seeds, as these can germinate and grow in to new plants. If the plant is being removed from gardens, dispose of it through local government kerbside collection or tip facilities. Fruiting shoot material should be bagged immediately to avoid it being dropped or dispersed by birds. Root material (which can survive being dried for long periods) and seeds should not be composted or mulched (CRC 2003).

Fire: Fire can also be useful in reducing above ground biomass of larger infestations. The effectiveness of fire as a control method is yet to be verified. Previous experiments using fire have had little impact on the underground tuber mat due to difficulties in maintaining fire intensity. In some high rainfall regions of South Australia, it has been observed that tubers grow in the leaf litter. A high intensity fire may 'cook' and ultimately destroy these tubers (Lawrie 2006).

Biological control: At present there are no biological control agents for Bridal Veil in Australia (Lawrie 2006).

For further information see the Asparagus Weeds Best Practice Management Manual (available at https://www.environment.nsw.gov.au/-/media/OEH/Corporate-Site/Documents/Animals-and-plants/Pests-and-weeds/asparagus-weeds-management-manual-130486.pdf ).

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Bridal Veil shoots begin to appear after the first autumn rains, usually during April or May, and scramble across the ground but do not generally climb to the same extent as Bridal Creeper (Asparagus asparagoides). The onset of cool winter weather sees shoots form dense foliage becoming deep green in colour. Above ground plant matter begins to whither and dies off when temperatures rise, usually during November-December, though drying fruit has been observed to stay on the plant through to January. Over the hot summer months Bridal Veil senesces back to the underground tuberous root mat (Lawrie 2006).

There is little knowledge of the growth rate of Bridal Veil. Based on research conducted by Raymond (1996a) it could be inferred that it has a similar growth rate to Bridal Creeper (Asparagus asparagoides). The underground, tuberous root mat ensures that during periods of unfavourable conditions (such as during a dry season or extended drought period) the plant can draw on nutrients and moisture contained within the storage organs (Pate & Dixon 1982). Observations made on Bridal Veil vigour and fruiting capacity during the 2002 drought in South Australia found that during this period, foliage turned a pale yellow colour and growth rate and vigour was reduced. Similarly, fruiting levels were lower than average during that season suggesting drought conditions adversely affect Bridal Veil (Bass & Lawrie 2003).

Where Is It Found?

Which states and territories is it found?

SA, VIC, WA.

What areas within states and territories is it found?

Bridal Veil (Asparagus declinatus) is currently known only from Western Australia and South Australia, and localised in Victoria around the Horsham area. However, in Victoria it is now thought the populations have been eradicated.

In Western Australia infestations have been recorded from Kings Park in Perth, further south at Bunbury and close to coast just west of Albany. In South Australia it is more widespread with infestations on the southern part of the Eyre Peninsula, the southern tip and central regions of the York Peninsula, the Fleurieu Peninsula and is dense  the eastern part of Kangaroo Island. Bridal Veil is also recorded from the southern Flinders Ranges (Lawrie 2006).

Where does it originate?

Bridal Veil is native to the south-west region of South Africa (Lawrie 2006).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

YES

Where is it a declared weed?

ACT, NSW, NT, QLD, SA, TAS, VIC.

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Asparagus declinatus

Other scientific names (synonyms)?

• Asparagus crispus Lam.
• Myrsiphyllum declinatum (L.) Oberm.

Does it have other known common name(s)?

Bridal Veil Creeper, Pale Berry Asparagus Fern, Asparagus Fern, South African Creeper