WSU Extension

Hortsense

Weeds : Groundsel, common : Senecio vulgaris
(revision date: 3/14/2019)

Family: Asteraceae (Compositae)
Cycle: Annual/Biennial
Plant Type: Broadleaf

Use Integrated Pest Management (IPM) for successful weed management.

Biology
Common groundsel may reach four to eighteen inches tall. Seedlings are small rosettes of deeply notched or lobed leaves one to four inches long and 1/4 as wide. Leaves are hairless to woolly or hairy. Leaves are alternate on the hollow stems of older plants. The lower stems and undersides of lower leaves are purplish in color. Flower heads are borne in clusters on somewhat branching stems. Each 1/4- to 1/2-inch flower head is broadest at the green base and narrow at the top, with yellow disk flowers barely visible at the top. Ray flowers or "petals" are absent. Seeds are tipped with silky white hairs, somewhat like dandelion seeds. SPECIAL INFORMATION: Common groundsel seedlings may be mistaken for seedling tansy ragwort plants (Senecio jacobaea). Both species are toxic to cattle and horses, causing chronic liver damage. Common groundsel is designated as a Class 'C' noxious weed in WASHINGTON. Management may be required by law in your county. Consult your local Noxious Weed Control Board for more information.
Habitat
Common groundsel grows on moist, rich soils in gardens, croplands, and waste areas. It is widespread throughout the Pacific Northwest.

Management Options

Non-Chemical Management
  • Weed infestation can be reduced by cultivation methods such as rototilling or hoeing, where practical.
  • Reduce weed infestation by handpulling weeds.
  • Careful digging is useful to manage weed populations. However, digging can carry undesirable weed seed to the surface and foster further germination.
Select non-chemical management options as your first choice!

Chemical Management

Apply according to label directions. Glyphosate products should be applied as spot treatments only! NOTE: Some ingredients listed here are only available in combination. Read the label carefully on combination products to make sure the product is suitable for your specific situation.

Landscape areas
  • glyphosate
  • dichlobenil
Turf areas
  • products containing 2,4-D
Bare ground areas
  • glyphosate
Images
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Caption: Common groundsel
Photo by: R. Parker
Caption: Common groundsel flower heads
Photo by: D.G. Swan
Caption: Common groundsel seed heads
Photo by: R. Parker
Caption: Groundsel buds
Photo by: T. W. Miller