oxalates nitrates
Flower Color:
  • flower color
fields, wasteareas, wetlands, roadsides

Time of Greatest Risk


Geographical Distribution

Curly dock distribution - United States

Related Species

Curly Dock

Rumex crispus

Yellow Dock, Curled Dock, Sour Dock, Reguette, Língua-de-vaca, Paciência, Krusskräppa, Rumex Crêpu
5/ 10
Curly dock (Rumex crispus ) is a perennial broadleaf weed. Curly dock is found virtually everywhere in the world, naturalized and in some places invasive.

Curly dock Identifying Characteristics
  • Height: 5 ft (1.5 m)
  • Flowers: Greenish to reddish-brown clusters of sepals, along the upper portion of the elongating stem.
  • Leaves: Ground-level leaves are dark green to reddish-purple (as they age), rosette-style, petioled, hairless, alternately arranged leaves with wavy margins. Leaves along the stem are alternatively arranged with a membranous sheath.
  • Fruit: Triangular-shaped, brown to reddish brown, glossy achenes; surrounded by a papery 3-valved or 2-winged structure.
  • Stems: Typically reddish, thick, hairless, ridged, and unbranched.
  • Root system: Large, yellow to orange, fleshy taproots.

Toxic components
All parts of curly dock are toxic to horses as it has the ability to accumulate high levels of nitrates and oxalates.


  • Listlessness
  • Dullness
  • Incoordination
  • Weakness
  • Coma
  • Excess Salivation
  • Tremors
  • Recumbency
  • Sudden Death


MECHANICAL CONTROL: Mowing will prevent seed production and reduce top growth. Tillage that completely destroys the taproot is effective.

CHEMICAL CONTROL: If applied in the spring it will control seedling plants. Herbicide application in the fall is the best timing for controlling established plants. Herbicides that contain glyphosate (> 1.25lb ae/A at bud to early flower stage or in the fall after a light frost); thifensulfuron (>0.33 oz ai/A); tribenuron (>0.1875 oz ai/A) plus thifensulfuron 2,4-D, or MCPA, aminopyralid, bromoxynil, or clopyralid are effective at controlling curly dock.