Missoula County Weed District & Extension

Houndstongue

 

Houndstongue
CYOFrosette
 houndstongue dog

Boraginaceae or Borage Family
Cynoglossum officinale

IDENTIFICATION:
Growth Habit:
Biennial, grows up to 3 feet tall.
Leaves: Velvety to touch, lower: broad, upper: narrow and clasps the stem.
Stems: Heavy, erect, branched above.
Flowers: Dark red to purple, 1/4 inch in diameter, grows in clusters. Native hounds tongues have a blue flower.
Roots: Taproot.
Seeds: Produces 300-675 seeds per plant, viable up to 2-3 years.
Reproduction: By seed.
Habitat: Pastures, roadsides, and waste areas.

MANAGEMENT OPTIONS:
Handpulling: Handpulling, especially with the aid of a shovel, can be a very effective method of control on patches of both rosettes and flowering houndstongue plants at any time during the growing season. Pulled plants that are in or past the flowering stage should be placed in plastic bags and removed from the site to prevent seed dispersal.
Mowing: Can be a very effective method of control for bolting individuals if done before flower, but will not effect rosettes of houndstongue.
Biological Control:  N/A
Grazing: Grazing is not a recommended method of control for houndstongue due to it containing high levels of pyrrolizidine alkaloids that are poisonous to livestock. Grazing will only increase pressure on competitive, desirable species.
Herbicide: The use of herbicides on houndstongue should focus on individuals that are in the rosette or bolting stages, as flowering individuals will already die at the end of the season (houndstongue is a biennial). The following herbicides have been labelled for control of houndstongue. Always consult product labels and read them carefully to ensure correct species/land management usage and chemical application.

Trade Name: Active Ingredient: Rate: Efficacy: Comments:
Escort  metsulfuron  .5-1 oz/acre most effective if applied at rosette to late bud stage  Cannot be used near wells, surface water or shallow ground water. 
 Telar  chlorsulfuron  .5-1 oz/acre most effective if applied at rosette to late bud stage
 2,4-D  2,4-D  2 qts/acre most effective if applied at rosette stage