Clockweed (Oenothera curtiflora)

Clockweed is an annual garden plant. It has become an invasive environmental weed in some locations.

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How does this weed affect you?

Clockweed is a garden escape that has become an invasive environmental weed particularly along roadsides, creeks and waterways. 

What does it look like?

Clockweed is an annual hairy herb growing to 1 m high.

Leaves are oval shaped, up to 12 cm long and 4 cm wide and have tiney teeth along the margins.

The white flowers are very small with petals only 2-3 mm long. They open around sunset and last less than one day. They become reddish or yellow with age.

The fruit is a stiff capsule, 10 mm long and 2 mm wide. 

Where is it found?

Clockweed grows in the Murray, Riverina, North West, North Coast, Western and Central West regions of NSW. Plants are often found along waterways.

It is native to America. 

Maps and records

  • Recorded presence of Clockweed 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?

Clockweed is commonly grown in gardens and it has spread by seed into nearby bushland areas.

More information

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Control

Hand weeding

Seedlings and small plants can be hand pulled or chipped out using a hoe or other garden tool. Weeding will be easier in damp soil. Remove the whole plant and dispose of any plant parts appropriately to prevent regrowth or spread.

Chemical control

Spot spraying

Spray actively growing plants. Cover all of the foliage.

Splatter gun

Splatter-guns use small amounts of concentrated herbicide. They spray large droplets that limit spray drift. They are useful for very dense infestations of weeds that are difficult to reach.

Wiping

Wipers or wands apply herbicide directly onto leaves. This can better target the chemical and minimise damage to other species.

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 31/03/2025
Fluroxypyr 200 g/L (Various products)
Rate: 500 mL to 1 L per 100 L water
Comments: Spot spray
Withholding period: Do not graze failed crops and treated pastures or cut for stock feed for 7 days after application. See label for further information.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate


PERMIT 9907 Expires 31/03/2025
Fluroxypyr 333 g/L (Staraneā„¢ Advanced)
Rate: 300 to 600 mL per 100 L water
Comments: Spot spray
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: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate


PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: One part product to 50 parts water
Comments: Spot spray
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate


PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: One part product to 9 parts water
Comments: Splatter gun
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate


PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: One part product to 20 parts water
Comments: Wipe onto leaves
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate


PERMIT 9907 Expires 31/03/2025
Metsulfuron-methyl 600 g/kg (Various products)
Rate: 10 - 20 g per 100 L water plus surfactant
Comments: Spot spray
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: 2 (previously group B), Inhibition of acetolactate and/or acetohydroxyacid synthase (ALS, AHAS inhibitors)
Resistance risk: High


PERMIT 9907 Expires 31/03/2025
Metsulfuron-methyl 600 g/kg (Various products)
Rate: 10 g per 1 L of water plus surfactant
Comments: Wipe onto leaves
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: 2 (previously group B), Inhibition of acetolactate and/or acetohydroxyacid synthase (ALS, AHAS inhibitors)
Resistance risk: High


2,4-D amine 700 g/L (Amicide Advance 700)
Rate: 285 mL in 100 L water
Comments: Pastures, rights of way and industrial areas
Withholding period: Do not graze or cut for stock food for 7 days after application.
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.
Western 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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For technical advice and assistance with identification please contact your local council weeds officer.

Reviewed 2023