IPMP3.0, Oregon State University, Copyright 2000

Biology and Management of Common Groundsel

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Registered Herbicides

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Common Groundsel

General Description:

  • simple or branched upright growth, 6-18 inches tall.
  • foilage is generally smooth but may have light pubescence.
  • alternate leaves are irregularly and deeply lobed - upper leaves attached to stem directly.
  • basal leaves have a purple color on underside.
  • yellow disk flowers are numerous.
  • fruit is ridged, slender and slightly pubescent.
  • young plants appear as rosettes.
  • small taproot with secondary fibrous root.
  • contains the same pyrrolididine alkaloids found in tansy ragwort and may cause liver damage in horses and cattle (though not as toxic as tansy).
  • biotypes have evoloved which are resistant to triazine and dinitroaniline herbicides.

Life cycle:   winter or summer annual, sometimes acts as a biennial

  •  reproduces by seed.
  • germinates early spring - late fall.
  • may produce 3-4 generations in one season.
  • seedlings: cotyledons and young leaves are purple on underside
  • flowers April - Ocotober.
  • seed can mature in opened flowers even after plants have been killed.

 Impact on Yield:

  • Although groundsel is not a strong competitor, heavy infestations have the potential to reduce mint yields. In one study, a medium infestation of groundsel caused a loss of 12 lbs per acre of peppermint oil (Ian Heap).

 Habitat/Crops associated with:

  • prefers cool and wet envirnonment - and nutrient rich soil.
  • nusery stock, landscape, vineyards.
  • mint, wheat (west of the Cascades).

Herbicide Control Notes:

  • Resistance to Buctril common in some regions. The combination of Gramoxone and Goal is very effective during the dormant season. Stinger most effective in fall or tank-mixed with Buctril or Basagran in spring.