weeds of national significance
Bridal creeper – Asparagus asparagoides
Current Potential
Bridal creeper (Asparagus asparagoides) The problem
Bridal creeper is a Weed of National Bridal creeper Significance. It is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts.
Bridal creeper entered the country as a – Asparagus asparagoides garden plant and is now a major weed of bushland in southern Australia, where its climbing stems and foliage smother native plants. It forms a thick mat of underground tubers which impedes the root growth of other plants and often prevents seedling establishment. Rare native plants, such as the rice flower Bridal creeper is a major weed of bushland in southern Australia, where its climbing vegetation smothers native plants. Pimelea spicata, are threatened with Photo: Louise Morin, CSIRO extinction by bridal creeper. It invades undisturbed habitats and is The underground mat of rhizomes and Key points a major threat to most low shrubs and tubers makes up the bulk of the plant. groundcover plants in mallee, dry These tubers provide water, energy and • Prevent new areas from becoming infested sclerophyll forest and heath vegetation. nutrients that enable the plant to survive by safely disposing of garden waste. In South Australia and southwestern over summer and allow rapid shoot • Spraying herbicide is the most effective method Western Australia bridal creeper is growth in autumn. of controlling bridal creeper. considered the most important weed Twisting stems grow up to 3 m in • Biological control is also having an impact threat to biodiversity. length, with leaves borne in groups on in many areas; local communities can become It also causes losses to primary industries short side branches. Numerous shoots involved in rearing and releasing the bridal (eg by shading citrus and avocado trees are produced from one patch of roots creeper leafhopper and spreading the rust fungus. and interfering with fruit picking), espe- and entwine with each other and the • It will take many years for the biocontrol cially in the Murray River irrigation area. native vegetation, making it almost agents to reduce the density of bridal creeper impossible to identify individual plants. due to the huge reserves stored underground The weed Bridal creeper produces pea-sized in tubers. green berries which ripen to red and Bridal creeper has annual, climbing shoot usually contain two or three black seeds. growth from a perennial root system Although one of its common names consisting of many tubers (food storage is ‘smilax’, it is not related to native organs) grouped along a central rhizome species in the genus Smilax. (an underground stem with shoot buds). 2
Growth calendar Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Flowering 30 mm Fruiting Dieback Regrowth Germination
General growth pattern Growth pattern in suitable conditions
Seeds germinate in autumn and winter in leaf litter and at soil depths of up to 100 mm. Buried seed that does not germinate rots within two years, while seeds on the soil surface may be viable for at least three years. Compared to many other weeds, Bridal creeper tolerates a wide range of soil and climatic conditions and, unlike many other weeds, bridal creeper has a short-lived seedbank. can establish in undisturbed areas. Photo: Weeds CRC Shoots of bridal creeper typically emerge from the soil in autumn but earlier emergence can occur in years of high summer rainfall. Shoots may be present year round in areas which normally have summer rains or are under irrigation. Bridal very popular in floral arrangements, creeper plants take at least three years to reach flowering size, the flowers appearing especially bridal bouquets, and as a along the length of the shoots in August and September. The green berries turn plant for hanging baskets. red in late spring to early summer.
There can be large differences in fruit production between years and sites. Early Where it grows autumn rains allow a longer growing season, which favours high fruit production. Bridal creeper is widespread in The amount of fruit set is significantly greater where shoots are able to grow vertically southwestern Western Australia, southern by climbing up shrubs and trees, and less where the plants are heavily shaded, South Australia and eastern Victoria. – Asparagus asparagoides suffer water stress or where there is a high level of competition between shoots Although it is spreading through New (ie older, dense infestations). South Wales and Tasmania, it could still be eradicated there with a sustained effort. Leaves turn yellow and fall and stems die back in late spring – early summer as temperatures rise and soils become dry. As well as a wide range of natural habitats, bridal creeper grows well in citrus orchards
Bridal creeper Bridal creeper and pine plantations. It can grow in most How it spreads soils but is most common close to the coast where it invades woodlands and Bridal creeper plants can produce more other open coastal vegetation. It is than 1000 berries per square metre. Birds particularly vigorous in alkaline sandy feed on the berries and later excrete the soils and thrives in areas high in nutrients seeds at perch sites, usually within 100 m such as drainage lines. Roadsides next of source plants. However, seed dispersed to farms are favoured sites because of by birds has helped spread the weed increased nutrient levels from fertilised along roadsides and into native vegetation paddocks. Bridal creeper is frost tolerant patches further afield. Rabbits and foxes and its perennial root system enables it 8 mm also eat fruit and disperse seeds. to survive summer drought.
The plant can spread as the root system slowly expands in area. Movement of Potential distribution soil containing roots (eg by grading) can Bridal creeper could potentially extend spread plants further. Dumping of garden its current distribution into southeastern rubbish containing bridal creeper seeds Queensland. It could also spread further or roots also spreads the weed. and increase its density in regions where Bridal creeper was first recorded in it is present but not widespread, eg the Bridal creeper produces bright red berries, which are eaten by birds and foxes, enabling it to be a nursery catalogue in 1857. With its central north and far southeast coasts spread over long distances. dainty white flowers and stems covered of Western Australia and northern and Photo:Colin G. Wilson with heart-shaped green leaves, it proved southwestern Victoria.
Weed Management Guide • Bridal creeper – Asparagus asparagoides 3
Herbicides
Herbicides have been the most effective method of control. However, because bridal creeper 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 reinfested.
Off-target impacts have been a concern where herbicide has not been applied Physical removal is not effective unless all the rhizomes are dug up and destroyed. Photo: Kate Blood carefully. The best way to apply it is with a hand sprayer, but it can also be wiped directly on the leaves. Using a herbicide What to do about it When searching for bridal creeper, check coloured with dye helps show where tree corridors and taller trees on the it has been used and limits spillage Bridal creeper has a number of features edges of native vegetation. Weed surveys and wastage. which make it difficult to control – its tuber should extend several hundred metres reserves provide a buffer against adverse from source infestations to ensure most Biological control seasons, it has a wide germination range of the bird dispersed seeds/seedlings and, unlike some other weeds, it can are picked up, and buffer zones for In South Africa bridal creeper is an invade undisturbed sites. bridal creeper should be 500 m wide uncommon plant that is kept in check around the edge of an infestation. by its natural enemies. But there are also weaknesses in its Within the buffer zone the aim is to biology – it has a relatively short-lived Three of these enemies have been limit further spread. The conventional seedbank, seed production only occurs released in Australia: the bridal creeper approach is to focus on the small on early emerging stems, and the seed leafhopper (Zygina sp.), rust fungus patches at the edge of an infestation, output in old infestations is small. (Puccinia myrsiphylli ) and leaf beetle working back towards the centre. (Crioceris sp.). However, an alternative approach is to It is vital to keep uninfested target the larger climbing infestations The bridal creeper leafhopper has areas free of bridal creeper that produce the most seed and are thus been released at more than 700 sites throughout southern Australia since Gardeners must be discouraged from most attractive to birds. A two-pronged 1999. The adult insect is white, 2–3 mm planting bridal creeper, and encouraged attack may be best but research is needed long and lives on the underside of to replace existing plants with desirable to confirm this. species and safely dispose of garden waste. Mapping is important to determine what area of bridal creeper is present in a region; where infestations are located (particularly in relation to areas of significant native vegetation); which infestations are eradicable; which 2 mm infestations are likely to be major seed sources; and where buffer/control zones 40 mm should be located.
New infestations of bridal creeper are The many shoots entwine with each other and The bridal creeper leafhopper (Zygina sp.) the native vegetation, making it almost impossible has been released at more than 700 sites often associated with the tallest trees, to identify individual plants. throughout southern Australia. reflecting preferred bird perching sites. Photo: Colin G. Wilson Photo: CSIRO
Weed Management Guide • Bridal creeper – Asparagus asparagoides 4
Weed control contacts
State / Department Phone Email Website Territory ACT Environment ACT (02) 6207 9777 [email protected] www.environment.act.gov.au NSW NSW Agriculture 1800 680 244 [email protected] www.agric.nsw.gov.au Qld Dept of Natural Resources and Mines (07) 3896 3111 [email protected] www.nrm.qld.gov.au SA Dept of Water, Land and (08) 8303 9500 [email protected] www.dwlbc.sa.gov.au Biodiversity Conservation Tas Dept of Primary Industries, 1300 368 550 [email protected] www.dpiwe.tas.gov.au Water and Environment Vic Dept of Primary Industries/Dept 136 186 [email protected] www.dpi.vic.gov.au of Sustainability and Environment www.dse.vic.gov.au WA Dept of Agriculture (08) 9368 3333 [email protected] www.agric.wa.gov.au
Australia wide Australian Pesticides and Veterinary (02) 6272 5852 [email protected] www.apvma.gov.au Medicines Authority Bridal creeper For up-to-date information on which herbicides are registered to control bridal creeper and the best application methods and dosages, contact your state or territory weed management agency or local council. This information varies from state to state and from time to time. Contact details are listed above, including contacts for the Australian Pesticides and Veterinary Medicines Authority, which hosts the PUBCRIS database. This database contains information on all herbicides that are registered for use on weeds in each Australian state and territory.
When using herbicides always read the label and follow instructions carefully. Particular care should be taken when using herbicides near waterways because rainfall running off the land into waterways can carry herbicides with it. Permits from state or territory Environment Protection Authorities may be required if herbicides are to be sprayed on riverbanks. – Asparagus asparagoides bridal creeper leaves. Both the adult and juvenile stages feed on the leaves of the weed, causing them to turn white and, in severe cases, fall off. The plant will continue to grow but with much less 40 mm vigour. Continual damage over several years will reduce new tuber production, making it less competitive.
Rearing the leafhopper is easy and many schools and community groups The bridal creeper rust fungus attacks leaves Physical removal of established bridal creeper have become involved in breeding up and stems, reducing the amount of green plant infestations is made virtually impossible by the populations for local release. It can material. extensive mats of tubers. produce several generations a year and Photo: John Virtue Photo: Kathryn Batchelor females are highly reproductive, so populations can quickly increase. some of the spores onto the leaves, to new areas. Trial releases in other The bridal creeper rust fungus was spraying them with water, covering regions are continuing. them overnight with a plastic bag, then released in 2000 and more than 700 It will take many years for the biocontrol removing the plastic bag the next day. releases have been made across Australia. agents to reduce the density of bridal The rust fungus attacks leaves and stems, The techniques to redistribute the creeper due to the huge reserves stored reducing the amount of green plant leafhopper and the rust fungus are underground in tubers. material. It can produce many generations described in detail on the CSIRO a year, resulting in large amounts of wind- website, which also has a map of Other control methods dispersed spores. It produces an over- release site locations Physical removal is not effective unless summering spore to survive the summer
Weed Management Guide • Bridal creeper – Asparagus asparagoides 5
Fire can help in larger infestations. Fires Trials with biocontrol agents began in above-ground growth and further reduce in late summer and early autumn can citrus orchards in 2001. the stored root reserves. Infestations remove all understorey vegetation and should be monitored regularly and over improve access for later spraying. In Disposal several years because of the probability winter-rainfall areas, bridal creeper often of regrowth from remnants of the root If the plant is being removed from emerges before the first autumn rains system. Regularly check for new incurs- gardens, dispose of it through local so herbicides may be applied before post- ions, carefully removing them or treating government kerbside collection or tip fire regeneration of native vegetation. them with herbicide, as necessary. For facilities. Fruiting shoot material should As well as improving the effectiveness new or small infestations hand digging be bagged immediately to avoid it being of herbicide application, fire may help of roots may be an appropriate follow- dropped or dispersed by birds. Root to destroy bridal creeper seed and the up technique. material (which can survive being dried dense tuber mat. for long periods) and seeds should not However, use of fire requires permission be composted or mulched. Legislation from government authorities and its Bridal creeper is a declared noxious weed frequent use may endanger the survival Follow-up in South Australia, New South Wales and of many native plant populations. Follow-up actions are required after Tasmania, meaning that landholders in treatment. If fire is used, regrowth should these states are required to control it. Grazing be treated carefully with herbicide to limit It is not declared in Victoria although it is a major weed there. Bridal creeper is Grazing can provide some control of listed as a prohibited plant in Western bridal creeper. Tamar wallabies on Australia, meaning that it cannot be Garden Island in Western Australia have brought into the state. successfully kept it at low levels there, and sheep grazing may be an option to control it under trees in remnant Acknowledgments vegetation, woodlots and shelterbelts.
– Asparagus asparagoides Information and guide revision: John Virtue (SA DWLBC/Weeds CRC), Control in horticulture Kathryn Batchelor (CSIRO), Louise Morin In citrus and avocado orchards it is (CSIRO), Richard Carter (NSW Agriculture/ difficult to spray bridal creeper entwined Weeds CRC), Beverley Overton (Kangaroo in the leaves of trees. Pruning lower limbs Island Bridal Creeper Control Committee)
Bridal creeper Bridal creeper to provide access underneath trees, a and John Thorp (National Weeds Bridal creeper causes losses in citrus orchards by Management Facilitator). practice known as ‘skirting’, enables spot shading trees and interfering with fruit picking. spraying with a recommended herbicide. Photo: Rae Kwong, DPI Vic Maps: Australian Weeds Committee.
Strategic management of bridal creeper on Kangaroo...case Island study
At the eastern end of South Australia’s Mapping and identifying control areas owners are gradually taking over treated Kangaroo Island bridal creeper is causing has been an integral part of the strategy, areas to ensure they remain weed free. devastation. It has smothered the says Beverley Overton of the Kangaroo In 2003 contractors will also be collecting understorey of many roadside verges Island Bridal Creeper Control Committee. and spraying rust fungus as an experiment. and is even killing small trees. It is also While herbicides continue to be the main Spread of the fungus by wind is very extending into the island’s national parks. method of control, field trials of the bridal variable so the committee hopes to A targeted control program involving creeper leafhopper and rust fungus, obtain better establishment by spraying landholders, community groups, national which have both been released on the it with water, particularly in inaccessible park rangers and weeds officers is island since 2000, are taking place. locations such as along creek lines. underway to tackle the problem, and Although the leafhopper has not had After eight years the control program is being partly funded through the a major impact, the rust fungus is doing has achieved significant results. Three Commonwealth Government’s Natural exceptionally well in several locations. years after spraying, infestations 2 m Heritage Trust. Contractors have been spraying high and 2 m deep have been reduced case studyinfestations with herbicide and property to a few tendrils. Weed Management Guide • Bridal creeper – Asparagus asparagoides Quick reference guide
Prevent new outbreaks major seed sources, and where buffer/ control zones should be located. Do not plant bridal creeper in your garden; replace existing plants with New outbreaks desirable species and safely dispose of garden waste. Keep 500 m buffer zones New outbreaks are often associated with for bridal creeper around the edge of the tallest trees, where seeds have been an infestation. spread by birds. Isolated plants can be treated with a recommended herbicide A strategic approach applied by spot spraying. As infestations become larger, a strategically staged Because of extensive storage reserves approach for removal is advisable to in the root tissues, the most effective ensure that treated areas are not reinfested. means of managing bridal creeper The best way to apply herbicide on bridal creeper involves integrating a range of is with a hand sprayer. Follow-up Photo: Kate Blood treatment techniques. Follow-up actions are required after On a regional scale mapping is important
– Asparagus asparagoides treatment. After fire treat regrowth of the probability of regrowth from to determine the area of bridal creeper carefully with herbicide to limit above- remnants of the root system. Regularly that is present, where infestations are ground growth and further reduce the check for new outbreaks. It may be located and which ones are likely to be stored root reserves. Monitor infestations possible to hand dig roots in new or regularly and over several years because small infestations. Control options Bridal creeper Bridal creeper
Type of infestation Herbicide Physical Fire Mechanical Biological Isolated plants or Once plant is correctly Remove isolated Not suitable. Not suitable. Not suitable. small infestations identified, treat with plants before seeding. registered herbicide. Be sure to remove all underground rhizomes and tubers. Larger infestations Apply after Not suitable. Use a prescribed burn Slashing the stems and Community groups can a prescribed fire in in autumn followed foliage may prevent become involved in autumn when growth by application fruit production and rearing the bridal is most vigorous. of herbicide. deplete root reserves, creeper leafhopper and Avoid contact with but must be continued distributing the rust desirable plants or soil over several years in fungus. See CSIRO near tree root zones. the absence of other website (details on p.4) treatments. for more information. Orchards Spot spray with Prune lower limbs Not suitable. Not suitable. Trials began in citrus recommended to provide access orchards in 2001. herbicide. under trees.
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