Ochna (Ochna serrulata)

Also known as: Mickey mouse plant

Ochna is a shrub with yellow flowers and distinctive black berries surrounded by red sepals. It invades bushland and can dominate the understory.

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How does this weed affect you?

Ochna is a very hardy plant that can:

• outcompete native plants
• reduce food and habitat for native animals
• form dense infestations that restrict movement of people and animals.

What does it look like?

Ochna is an evergreen perennial shrub that grows 2–3 m tall. The black berries on the red sepals look like Micky Mouse’s face.

Leaves are:

• light to dark green and sometimes bronze on new growth
• usually darker green on top and lighter underneath (mature leaves)
• narrow and oblong
• 2–10 cm long and up to 2.5 cm wide
• finely toothed along the edges and often wavy overall
• on short stalks
• alternate along the stem

Flowers:

• have 5 yellow petals, each up to 10 mm long
• have 5 green sepals (leaf-like structures) up to 8 mm long which curve backwards and turn red, staying on the plant below the fruit
• are up to 3 cm wide overall
• are usually single, growing on short stalks between the leaves and branches
• are present in spring.

Fruit are:

• green turning black when ripe
• 5–8 mm long
• oval-shaped
• in rings of up to 6 fruit surrounded by 5 red sepals up to 1.5 cm long 
• single seeded
• present from September–March with most fruit ripening in December.

Stems are:

• green or bronze when young
• brown when older
• covered in tiny lumps (lenticels).

Roots are:

• deep, even on small plants
• kinked part way along the taproot
• woody.

Where is it found?

In NSW, ochna grows in coastal regions from Illawarra in the South East region to the Queensland border. It is common in the Greater Sydney and North Coast regions. It has also been found in the Northern Tablelands.

Ochna was introduced as an ornamental garden plant. It is native to southern Africa.

What type of environment does it grow in?

Ochna grows well in shade or full sun on a wide range of soil types from sand to clay. It tolerates extended dry spells but is sensitive to frost. Ochna often invades disturbed sites but can also grow in native vegetation that has had no disturbance. It has been found growing:

• in rainforest and sclerophyll forests
• in cleared paddocks
• in road reserves
• along river and creek banks.

How does it spread?

By seed

Ochna does not produce seeds until the plants are 3 years old. Seeds usually germinate within 1 month and are only viable for up to one year. Birds eat the fruit and spread the seeds, often from garden plantings into nearby bushland. Seeds can also be spread by people dumping garden waste that contains fruiting ochna.

References

Breaden, R., & Armstrong, T. (2004). Control methods for ochna (Ochna serrulata)(Hochst.) Walp. in south-east Queensland. Plant Protection Quarterly, 19(1), 33.

Gosper, C. R., Vivian-Smith, G., & Hoad, K. (2006). Reproductive ecology of invasive Ochna serrulata (Ochnaceae) in south-eastern Queensland. Australian journal of botany, 54(1), 43-52.

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) (2020). Ochna serrulata (Hochst.) Walp. 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=Ochna~serrulata

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.

To manage ochna:

• dig out small plants (under 20 cm) making sure that all the roots are removed
• control plants before they fruit (plants take at least three years to produce fruit)
• check and follow-up initial control efforts as this weed is very hardy and often re-sprouts.

Physical removal

By hand

Do not try to pull out plants as they will break off where the root kinks and the plant will regrow. Dig out small plants and seedlings (under 20 cm tall) if the soil is sandy or soft enough. Remove as much of the roots as possible.

Disposal

For advice about the best way to dispose of ochna fruit, contact your local council weed officer.

Chemical control

When: Anytime but best during warm wet summers.

Follow-up: When regrowth appears. Ochna is very hardy and more than one treatment is often needed.

Spot spraying

Spraying is best for plants below knee high. Apply to all foliage to the point of visible wetness.

Gas guns

Use this method (also known as the ‘splatter gun’ technique) for plants up to 1 m tall. Apply a small amount of concentrated herbicide and a marker dye onto the leaves of the plant by painting lines of the herbicide mixture in a cross hatch pattern. There is no need to saturate the plant using this method and it can be effectively used to avoid off-target damage to native or other desirable plants.

Scrape and paint method

This method is suitable for small plants with thin stems. Scrape the stem gently to expose the green layer under the bark. Start at the base of the plant and scrape as high as possible. Apply herbicide within 15 seconds of scraping.

Cut stump method

This method is suitable for plants with thick stems. Cut trunks or stems of the plant as low to the ground as possible and apply herbicide to the stump within 15 seconds of cutting. For best results, dig below the cut stump and scrape the stem to expose the green layer under the bark. Apply herbicide to the scraped stem within 15 seconds.

Stem inject

For large mature plants, drill holes around the lower stem of the plant using a 10 mm drill bit. Fill the holes with herbicide within 15 seconds. Remove and bag any fruit from the plant and dispose of appropriately.

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 glyphosate per 10 L of water
Comments: Spot spray. Apply to seedlings/ coppice shoots and shrubs.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
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 of water
Comments: Scrape stem, cut, and paint. Cut stump saplings. Stem injection large trees and shrubs.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
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 metsulfuron-methyl per 10 L of water
Comments: Spot spray application.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate

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Fluroxypyr 333 g/L (Starane™ Advanced)
Rate: 600 mL in 100 L of water
Comments: Spot spray, Apply to plants up to 2 m tall
Withholding period: Do not graze failed crops and treated pastures or cut for stock food for 7 days after application. See label for more information.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Fluroxypyr 333 g/L (Starane™ Advanced)
Rate: 300 mL per 10 L of water
Comments: Gas gun application to plants up to 1 m.
Withholding period: Do not graze failed crops and treated pastures or cut for stock food for 7 days after application. See label for more information.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Picloram 44.7 g/L + 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 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 2022