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Curled dock (Rumex crispus)

Curled dock is an aggressive agricultural and environmental weed found across Australia, especially in wetter situations. Its dense growth crowds out other plants, and its deep root system and prolific seed production make it difficult to manage.

Key facts

Type: Weed, herb.

Native to: Europe and south-west Asia.

Established in: QLD, NSW, ACT, VIC, TAS, SA, WA.

Other names: Curly dock.

Best time to act: Look for seedlings emerging in autumn and spring, winter regrowth from established rootstocks, and flowering and fruiting plants by early summer.

Identification

  • A robust, upright perennial, usually 50–150 cm tall, with a taproot that can reach 3 m deep.
  • Large basal leaves form a rosette; their blades are puckered or wavy, especially around the margins, and can grow to 30 cm long.
  • Numerous upright branches carry dense clusters of flowers, followed by conspicuous rusty-brown fruiting heads.
  • Each three-sided fruit is surrounded by three persistent valves with untoothed margins and a small lump on the lower back.
  • Look-alike: Clustered dock also has untoothed valves, but is shorter, with wide-spreading branches and smaller flowers and fruit.
  • Look-alike: Sorrel (Acetosella vulgaris) has untoothed valves and upright branches, but is a much shorter, slender rhizomatous plant; native docks can be distinguished in fruit by their toothed valve margins.

Where it grows

It occurs in temperate regions of all Australian states, commonly in seasonally or semi-permanently wet, disturbed pastures and cultivation areas, roadsides and stream-banks, and also in some natural habitats.

Why it matters

  • Dense growth crowds out desirable plants and can shade other vegetation while depleting soil nutrients and moisture through its extensive root system.
  • It can become the dominant herbaceous plant, particularly in irrigated production areas, and competes with native species in wetlands, riverbanks and other plant communities.
  • Dense stands can obstruct irrigation and drainage channels, reduce grazing capacity, cause pasture yield losses and infest irrigated orchards and other plantation crops.
  • It produces about 60,000 seeds per plant and contains oxalates; it is suspected of poisoning stock, although it is generally considered unpalatable and levels are unlikely to be lethal.

How it spreads

  • It spreads by seed, and mature fruits on dried branches break off readily when brushed by people, animals or equipment.
  • Fruits may be transported by wind, mud and water.
  • Cultivation equipment can create crown and upper taproot fragments that regenerate.

Control options

  • Deep hoe or grub single plants, removing the plant carefully because crown and upper taproot fragments can regenerate.
  • For larger infestations, use a combination of cultivation and registered herbicides; in pastures, the spray/graze technique can reduce infestations.
  • Slashing and mowing are not effective.
  • The established stem- and root-boring moth Pyropteron doryliformis provides almost total control in Western Australia and good control in about 50% of infested areas in Victoria and New South Wales.

Hygiene and washdown

  • Mature fruits can be carried on people and equipment, so clean boots, gear and machinery after working in seed-bearing infestations and avoid moving contaminated mud or plant material.
  • Inspect and clean vehicles, plant and footwear before leaving an infested area, paying attention to tyres, radiators, belly plates, tracks and floor mats.
  • Wash down at a designated bay where runoff is contained and can be monitored for seedlings.
  • Record each washdown so the client has evidence of clean entry and exit.

Classification by state

  • Australia (national): No national listing. Managed under state and territory law.
  • Queensland: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Not a priority weed. Not a state or regional priority weed in NSW. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Not declared. Not declared under the Catchment and Land Protection Act 1994. Other Victorian laws may still apply.
  • South Australia: Not declared. Not declared under the Landscape South Australia Act 2019. Other laws may still apply.
  • Western Australia: Permitted, not declared. Listed as a permitted organism in WA, so it can be brought in, but it is not a declared pest.
  • Tasmania: Not declared. Not a declared weed in Tasmania. Other laws may still apply.
  • Northern Territory: Check NT list. There is no NT weed profile for it. Check the NT declared weeds list for its current status.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Queensland: Biosecurity Act 2014 (Qld), administered by Biosecurity Queensland (13 25 23)
  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Australian Capital Territory: Biosecurity Act 2023 (ACT), administered by ACT Biosecurity
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • Tasmania: Biosecurity Act 2019 (Tas), administered by Biosecurity Tasmania
  • South Australia: Landscape South Australia Act 2019 (SA), administered by the regional landscape board
  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development

Sources