Cherry guava (Psidium cattleyanum)

Profile

Impact

Cherry guava is an evergreen tree or shrub that can rapidly form dense thickets. It has naturalised in many coastal parts of Queensland and New South Wales and become a significant environmental weed on Lord Howe Island.

Cherry guava is an invasive woody weed that infests forests, woodlands, forest margins and grassland areas of tropical and sub-tropical areas. Able to tolerate shade, it completes with the understorey species of native rainforests, changing the biodiversity and structure of the forest. The invasiveness of this plant allows it to out-compete all other species present, forming a monoculture.

Cherry guava has been recognised as an important environmental weed in the Pacific region. It has been ranked as one of the world’s 100 worst invasive weeds by the International Union for the Conservation of Nature.

Distribution

Native to Brazil and Uruguay. Cherry guava has naturalised in Portugal, South Africa, La Réunion, the Seychelles, Mauritius, New Zealand, the USA, Hawaii, Micronesia and French Polynesia. It is considered one of the worst forest weeds of Hawaii and has had devastating effects on native habitats in Mauritius.

Originally introduced as an ornamental plant with edible fruit. It has escaped cultivation and was first recorded naturalised in the 1890s along the Daintree River in Queensland.

Cherry guava is now scattered in many locations along the east coast of Australia. It extends along the northern coastline of NSW from Tweed Heads through to Taree. It is a declared weed on Lord Howe Island and is also present on Norfolk and Christmas Islands.

Distribution map

Spread

Cherry guava reproduces from seed and vegetatively by producing suckers from the roots. Large numbers of attractive edible fruit are produced annually. Vegetative growth allows infestations to thicken and plants to spread locally. The soil surface of cherry guava infestations can often be a mat of sucker roots.

The berries of cherry guava are appealing to many animals. Birds, cattle and feral pigs feed on the fruit and spread the seed to new locations in their droppings. Seeds that pass through the gut of pigs have been found to germinate faster than those that haven’t. The rooting and trampling behaviour of feal pigs, combined with the large consumption of berries, provides a suitable environment for new cherry guava plants to grow and flourish.

Humans have also contributed to its spread by intentional plantings and dumping of garden waste in unauthorised areas.

Lifecycle

Cherry guava is a fast growing perennial plant. It quickly produces a dense population of suckers and seedlings.

Flowering occurs throughout the year, but is more prominent during the spring and summer months. Fruit forms from late summer into mid autumn.

Description

Cherry guava commonly grows 1–3 m in height but can reach heights up to 6 m.

Bark

  • young stems are smooth and may contain soft fine hairs
  • mature bark is grey to reddish-brown in colour
  • outer layers of bark peel away exposing inner layers

Leaves

  • occur in pairs on short stalks 4–10 mm long
  • oval in shape, tapering to a pointy end
  • pale to dark green in colour
  • up to 7 cm long and 4 cm wide
  • shiny surface with smooth edges

Flowers

  • fluffy in appearance
  • usually a single flower at the base of the leaf stalk, but can also occur in clusters of three
  • up to 2.5 wide
  • 5 white petals about 5 mm long with 5 green leaf-like structures on the underside (sepals)

Fruit

  • fleshy berry with a thin edible skin
  • up to 3.5 cm in diameter
  • round in shape
  • contains a white to yellow juicy pulp with up to 70 kidney-shaped seeds
  • changes from green to a purplish-red as it matures
  • 5 lobe like structures (the remains of the flower sepals) at the opposite end of the stalk

Similar species

Cherry guava is similar to other species Brazilian guava (Psidium guineense) and guava (Psidium guajava). These species have larger leaves with prominent veins. Cherry guava can be distinguished from other guava varieties by its purplish-red fruit.  

Habitat

Cherry guava prefers a tropical to sub-tropical climate. It will readily establish on disturbed sites, but is also capable of germinating in undisturbed, intact areas such as rainforest floors.

Able to grow on any soil type, it prefers open locations such as the edge of rainforests and scrub habitats. It is also shade tolerant, allowing it to spread further into a forest over time. It does not tolerate frosts.

Acknowledgements

Written by Rachele Osmond.

References

Brisbane City Council (2014) Weed identification tool: cherry guava (Psidium cattleianum var. cattleianum). Available at weeds.brisbane.qld.gov.au/weeds/cherry-guava

Department of the Environment (2011) Weeds in Australia: Psidium cattleianum, Australian Government. Available at www.environment.gov.au

Global Invasive Species Database (2005) Psidium cattleianum. Available at www.issg.org

Lowe S, Browne M, Boudjelas S and De Poorter M (2004) 100 of the world’s worst invasive alien species: a selection from the global invasive species database. The Invasive Species Specialist Group (ISSG).

Tunison T (1991) Element Stewardship Abstract for Psidium cattleianum Strawberry guava. The Nature Conservancy, Arlington, Virginia. Available at http://www.invasive.org/gist/esadocs/documnts/psidcat.pdf

US Forest Service, Pacific Island Ecosystems at Risk (2014) Online resource: Psidium cattleianum. Available at http://www.hear.org/pier/

Wilson P (2014) Psidium cattleyanum in PlantNET - The Plant Information Network System of The Royal Botanic Gardens and Domain Trust, Sydney, Australia. Available at http://plantnet.rbgsyd.nsw.gov.au

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Control

Manual control

Physical removal is best avoided in large infestations as the roots need to be removed and destroyed, so that plants do not regenerate.

Where practical, manually uproot small seedlings and saplings that have originated from seed. Although this can be very time consuming. Take care if using any form of manual control as plants can re-shoot from the roots.

Herbicide control

The best methods of herbicide application are cut stump, basal bark and stem injection. These methods can be conducted at any time of the year.

Always check controlled plants for re-shooting from stumps and roots. Treat as necessary.

Herbicide options

WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au

See Using herbicides for more information.


PERMIT 9907 Expires 31/03/2020
Fluroxypyr 200 g/L (Starane™)
Rate: 35 mL per 1 L of diesel
Comments: Basal bark application
Withholding period: 7 days.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L (Roundup®)
Rate: 1 part glyphosate to 1.5 parts water
Comments: Cut stump/ stem injection
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate


Picloram 44.7 g/kg + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump/stem injection 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: I, Disruptors of plant cell growth (synthetic auxins)
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 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 2014