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  • Noxious Weed Identification List

    Dalmatian Toadflax


    Linaria dalmatica

    Info sheet Adobe PDF Icon

    Colorado List B - Control required in Jefferson County

    General

    • Family: Scrophulariaceae (Figwort)
    • Grows from sea level to 9,200 feet
    • Herbaceous perennial
    • Introduced from Europe
    • Has been used as an ornamental but no longer available in Colorado
    • Individual patches can live for 13 or more years
    • Toadflax can significantly reduce crop yields and stress native communities

     

    Common Names

    • Wild snapdragon

     

    Habitat

    • Found in pastures, rangelands, roadsides, gravel pits and grasslands
    • Tolerant to low temperatures and coarse soils
    • Prefers open, sunny locations

     

    PLANT

    Vegetation

    • Mature plants up to 3 feet tall
    • Stems are woody at the base
    • Top growth dies back in fall, prostrate stems form in the fall and during winter
    • Produces 1 to 25 floral stems
    • Leaves are heart-shaped and clasp the stem
    • 1 to 3 inches long, 3/8 to 3/4 inch wide and waxy

     

    Roots

    • Taproots can reach 6+ feet deep
    • Lateral roots are found 2 to 8 inches deep, can extend horizontally 10 or more feet
    • New plants can develop from root buds 2 to 3 weeks after germination and from root fragments as small as 1/4 inch long

     

    Flower

    • Color: yellow
    • Season: spring to fall
    • Size: 3/4 to 1 1/2 inches long
    • Typically has a spur as long as the flower

     

    Seed

    • Each plant can produce up to 500,000 seeds
    • Remains viable up to 10 years
    • Seed capsules begin opening in July
    • Seed matures from July through September

     

    Seedling

    • Most emerge in April
    • Some fall germination possible under optimum conditions

     

    Reproduction

    • Seed and vegetative means

     

    CONTROL

    Biological

    • Calophasia lunula, a defoliating moth (L)
    • Brachypterolus pulicarius, Toadflax flower-feeding beetle (A)

     

    Chemical

    Please refer to our Info sheet Adobe PDF Icon

    Cultural

    • Prevention – maintain health of site
    • Fertilization to promote grass cover
    • Revegetation of highly disturbed sites
    • Removal of prostrate stems in spring and fall reduces floral stems

     

    Mechanical

    • Burning - Not recommended; deep roots protect the plant; areas disturbed by fire are susceptible to re-invasion due to lack of competition from desirable plants 
    • Grazing - Does not control; intensive grazing contributes to ideal habitat conditions, helping dalmatian toadflax spread; may be toxic to livestock 
    • Mowing - Not recommended 

     

    Use all chemicals according to the manufacturer's label. Listing the above methods or products does not imply a specific recommendation or endorsement.



    Alicia Doran
    Weed & Pest Management Specialist
    303-271-5989
    adoran@jeffco.us

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    weed-pest-b-dalmatian-toadflax-plant

    weed-pest-b-dalmatian-toadflax-leaves

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    Last Updated: 7-29-2013