Paper mulberry (Broussonetia papyrifera)

Paper mulberry is fast growing deciduous tree. It can outcompete native plants and its pollen can cause allergic reactions.

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How does this weed affect you?

Paper mulberry is a very fast-growing tree that:

• outcompetes native plants
• can reduce habitat and food for native animals
• forms dense stands
• can cause allergic reactions.

Human health

Paper mulberry produces lots of pollen which causes allergic reactions in some people.

What does it look like?

Paper mulberry is a deciduous tree that can grow to 20 m tall but is usually less than 12 m. It can grow 4 m in the first 6 months. There are separate male and female plants that have very different flowers.

Leaves are:

• 6–18 cm long and 5–9 cm wide
• oval or heart-shaped with a pointed tip
• often lobed with 3–5 lobes on young plants
• rough to touch above
• covered in soft short hairs on the lower side with coarser hairs along the veins
• toothed along the edges
• on stalks 23–80 mm long
• arranged in spirals on the stem.

Flowers:

Male flowers are:

• yellowish-white
• clustered together in a cylindrical spike that:
  • is 3–8 cm long
  • hangs down
  • contains about 200 flowers.

Female flowers are:

• green
• in clusters forming round balls 1.5–2.5 cm in diameter
• long, thin and tube-like with 4 small narrow sepals
• present in spring.

Fruit are:

• made up of clusters of many small drupes that form one roundish, fleshy fruit
• green when young
• orange to reddish-purple when ripe
• 15–30 mm in diameter
• ripe over summer and early autumn.

Stems:

• are pale brown and smooth or with shallowly grooved bark
• have light brown horizontal markings around the trunk
• are densely hairy and reddish-brown when small
• exude a milky, latex sap when broken.

Where is it found?

Paper mulberry has been found around Nimbin, Lismore and Upper Wilson’s Creek in northern NSW.

It is native to south-east Asia and was introduced as an ornamental or shade tree.

What type of environment does it grow in?

Paper mulberry is a pioneer species that grows best in sunny areas in warm-temperate, subtropical and tropical climates with 700–2500 mm annual rainfall. Trees grow best in moist, fertile, well-drained, lighter-textured soils, but can survive a 3–4 month dry season. It does not grow well in shaded areas.

In NSW, paper mulberries grow in:

• riparian areas
• margins and gaps in forests and vine thickets
• disturbed and open sites such as unmanaged farmland.

Maps and records

• Recorded presence of Paper mulberry during property inspections (Map: Biosecurity Information System - Weeds, 2017-2024)
  These records are made by authorised officers during property inspections under the Biosecurity Act 2015. Officers record the presence of priority weeds in their council area and provide this to the NSW Department of Primary Industries. Records reflect the presence of the weed on the date of inspection.
  
  

How does it spread?

By seed

If both male and female trees are present, paper mulberry can produce fruit and spread via seed. Birds, bats and other animals eat the fruit and spread the seeds in their droppings. Seeds can also be spread in moving water and dumped garden waste. Seeds rarely germinate under dense canopies but can germinate prolifically in canopy gaps.

By plant parts

Plants can spread short distances via root suckers and form dense thickets. Suckers often form when stems are damaged. New plants can grow from broken plant parts. Broken stems and roots can spread in moving water and in dumped garden waste.

References

Australia’s Virtual Herbarium: Broussonetia papyrifera. http://avh.ala.org.au/occurrences/search?taxa=Broussonetia+papyrifera#map

BioNET-EAFRINET Invasive Plants factsheet: Broussonetia papyrifera (Paper Mulberry). http://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Broussonetia_papyrifera_(Paper_Mulberry).htm 

CABI (2021). Broussonetia papyrifera (paper mulberry). In: Invasive Species Compendium. Wallingford, UK: CAB International. Retrieved 5 February 2021 from: https://www.cabi.org/isc/datasheet/10017

Csurhes, S. (2012). Invasive species risk assessment Paper Mulberry (Broussonetia papyrifera). Queensland Department of Agriculture, Fisheries and Forestry. https://www.daff.qld.gov.au/__data/assets/pdf_file/0011/67898/IPA-Paper-Mulberry-Risk-Assessment.pdf 

Hong, L., Yang, W., & Yiying, L. (2009). Structure of Flowers and Pollination Mechanism of Broussonetia papyrifera [J]. Journal of South-Central University for Nationalities (Natural Science Edition), 1. (Abstract only)[1] 

PlantNET (The NSW Plant Information Network System) (2020). Broussonetia papyrifera (L.) Vent. NSW Flora Online. Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 29 June 2020 from: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Broussonetia~papyrifera

University of Florida/IFAS Center for Aquatic and Invasive Plants (2014) Paper mulberry – Broussonetia payrifera. http://plants.ifas.ufl.edu/node/74 

Wu, P. C., Su, H. J., Lung, S. C. C., Chen, M. J., & Lin, W. P. (2019). Pollen of Broussonetia papyrifera: An emerging aeroallergen associated with allergic illness in Taiwan. Science of The Total Environment, 657, 804-810.

More information

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Control

Suspected plants should be reported to the local council weeds officer, who will provide assistance with identification, control and removal.

Physical removal

By hand

Young plants can be dug out. Remove as much of the roots as possible to prevent regrowth.

Chemical control

Herbicides can be effective in managing paper mulberry if applied during spring and summer when the plant is actively growing. Regular monitoring and follow-up of control of infested areas are essential.

Cut stump method

Cut trunks or stems and apply herbicide to the stump within 15 seconds of cutting. For larger plants, also scrape the cut stem and any above ground roots to expose the layer below the bark. Apply herbicide to the scraped areas within 15 seconds

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: 400 mL of glyphosate in 600 mL of water
Comments: Cut stump 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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Picloram 44.7 g/L + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump application. Apply a 3-5 mm layer of gel for stems less than 20 mm. Apply a 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.
North Coast	Regional Recommended Measure* (for Regional Priority - Eradication) Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found.
	*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here

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Reviewed 2023