Morning glory - coastal (Ipomoea cairica)

Also known as: mile-a-minute

Coastal morning glory is a vine weed with lobed leaves and purple funnel-shaped flowers. It smothers and outcompetes native plants.

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How does this weed affect you?

Coastal morning glory grows very quickly to form a dense mat along the ground or climbs into the canopy. It:

• smothers and outcompetes other plants including natives
• prevents native seedlings from growing
• reduces food and habitat for native animals
• contains calystegines, which can be toxic to horses and cattle, sheep or goats.

Invasion and establishment of exotic vines and scramblers has been identified as a key threatening process for many vulnerable and endangered species in NSW. Coastal morning glory is one of the main species listed as a threat.

What does it look like?

Coastal morning glory is a perennial vine with twining stems. It can grow up to 5 m into the canopy.

Leaves are:

• lobed with 5-7 deep lobes almost to the base
• 4-9 cm long and wide
• hairless or slightly hairy
• on stalks 2–5 cm long
• alternate along the stem.

Flowers are:

• violet purple or pink (occasionally white) with a darker throat
• funnel shaped with 5 fused petals
• 3.5–6 cm long and 6–8 cm in diameter
• hairless
• single or rarely in groups of 2 or 3
• on stalks 5–70 mm long
• present year-round but each flower only lasts one day.

Fruit are:

• a capsule
• green at first then brown when mature
• 9–11 mm in diameter
• divided into four compartments each with one seed.

Seeds are:

• black
• 4–5 mm long
• oval shaped
• hairy with longer hairs on outer ridges.

Stems:

• are cord-like when young and woody when older
• are usually hairless or slightly hairy
• have a white, milky sap, which is visible when cut.

Roots are:

• fibrous
• woody with a branching crown as they get older.

Similar looking plants

Coastal morning glory looks similar to other weed species, including:

•  Purple morning glory (Ipomoea indica), which has heart-shaped or three-lobed leaves.
• Common morning glory (Ipomoea purpurea), which has heart-shaped or three-lobed leaves. Also the flowers have a paler rather than darker coloured throat.

Where is it found?

Coastal morning glory grows along the NSW coastline from the Queensland border to Eurobodalla in the south. Isolated plants have also been found in the North West and Western regions.

 It is native to tropical regions of Africa and Asia. It was introduced to Australia as a garden ornamental.

What type of environment does it grow in?

Coastal morning glory grows in tropical, sub-tropical and warm temperate climates. It tolerates a wide variety of soil types including saline conditions. It is common in:

• coastal areas including sand dunes
• river banks including tidal estuaries
• rainforests
• woodlands
• disturbed areas such as gardens, often over fences.

How does it spread?

Most spread has been through intentional planting.

By seed

Plants can start producing seeds when they one year old. Seeds are spread by wind, moving water and birds.

By plant parts

Morning glory stems can grow new roots from the nodes. Broken stems can spread in moving water and by people dumping garden waste.

References

Harden, G., McDonald, B. & Williams, J.() Rainforest Climbing Plants: A Field Guide to Their Identification. Harden Publishing.

Identic Pty Ltd. and Lucid central (2016). Environmental Weeds of Australia Fact sheet: Ipomoea cairica. Retrieved 31_10_2023 from https://keyserver.lucidcentral.org/weeds/data/media/Html/ipomoea_cairica.htm

McKenzie, R. (2012). Australia's poisonous plants, fungi and cyanobacteria: a guide to species of medical and veterinary importance. CSIRO.

Muyt, A. (2001). Bush invaders of South-East Australia: a guide to the identification and control of environmental weeds found in South-East Australia. RG and FJ Richardson.

PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 31_10_2023 from https://plantnet.rbgsyd.nsw.gov.au/cgi-in/NSWfl.pl?page=nswfl&lvl=sp&name=Ipomoea~cairica

Richardson, F. J., Richardson, R. G., & Shepherd, R. C. H. (2011). Weeds of the south-east: an identification guide for Australia (No. Ed. 3). CSIRO.

More information

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Control

Successful weed control relies on follow up after the initial efforts. This means looking for and killing regrowth or new seedlings. Using a combination of control methods is usually more successful.

Physical removal

Hand pulling

Small plants and seedlings can be hand pulled. Some larger plants may be pulled out in soft sandy soils.

Cutting and digging

Climbing stems can be cut and left above the ground to dry out and die. Make sure no cut stems have contact with the soil. Dig out the crown and roots carefully as they can regrow from parts left in the soil.

Chemical control

Spot spraying

Spray actively growing plants and ensure that all of the foliage is covered with the herbicide mix. If vines are growing over desirable plants:

• cut stems at waist to chest height
• move stems that are connected to the soil away from desirable plants
• spray all of the foliage connected to the soil
• climbing stems can be left in place to wither and die. If there are any stems touching the ground, collect them and either take them off-site for disposal, or leave them on site to dry out without contacting the soil.

Regrowth can be spot sprayed with herbicides.

Cut stem method

Cut stems close to the ground, preferably within 10 cm from the soil. Apply herbicide gel to the cut surface connected to the soil within15 seconds of cutting. Climbing stems can be left in place to wither and die. If there are any stems touching the ground, collect them and either take them off-site for disposal, or leave them on site to dry out without contacting the soil.

Stem scraping

Cut stems to within 1 m of where the vine is firmly rooted in the soil. Use a sharp knife to scrape a very thin layer of bark from a 15–30 cm section of the stem. Apply the herbicide to the exposed soft underlying green tissue within 15 seconds of making the scrape. If there are any stems touching the ground, collect them and either take them off-site for disposal, or leave them to dry out on site, without contacting the soil. 

Disposal

Contact your local council for advice on how to dispose of this plant.

Herbicide options

See Using herbicides for more information.

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PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: 200 mL per 10 L of water
Comments: Spot-spray for seedling control.
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate

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PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: 1 part glyphosate per 1.5 parts water
Comments: Stem scraping application.
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate

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PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L with Metsulfuron-methyl 600 g/kg (Various products)
Rate: 200 mL glyphosate plus 1.5g of metsulfuron-methyl in 10 L water
Comments: Spot spray application
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate

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Dichlorprop 600 g/L (Lantana 600®)
Rate: 1 L in 200 L of water
Comments: Completely wet all leaves and stem of target plants
Withholding period: Nil.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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Picloram 44.7 g/L + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stem application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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Biosecurity duty

The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.

Area	Duty
All of NSW	General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable.

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Reviewed 2024