Dalmatian Toadflax

• Invasive:

Yellow or Common Toadflax (Linaria vulgaris): This plant is of the same genus, and has similar yellow flowers. Dalmatian Toadflax leaves are clasping, shorter and more broad-based than Yellow Toadflax. Yellow Toadflax is also shorter (up to 60 cm tall).

 

 

 

Origin: Dalmatian Toadflax is native to Western Asia as well as the Mediterranean region; it was introduced to North America in the late 19th century as a garden ornamental.

Habitat: Dalmatian Toadflax is most commonly found on sandy or gravely soil on roadsides, railroads, pastures, cultivated fields, rangelands and clearcuts. It is adapted to a wide variety of conditions: it thrives in poor, dry soils, but can also cause issues in high-quality soils. Dalmatian Toadflax does well in sunny to partly shaded conditions.

Dalmatian Toadflax is often associated with several other invasive species. For example, it often moves in after Diffuse and Spotted Knapweed are controlled. Similarly, Dalmatian Toadflax has been observed on rangeland sites after biological control suppressed St. John’s Wort.

Dalmatian Toadflax reproduces by seed and vegetatively. One mature plant can produce up to 500,000 seeds each year, and seeds remain viable in the soil for up to 10 years.

It also reproduces vegetatively via creeping rhizomes, and from root fragments.

Dalmatian Toadflax seeds are extremely small, so they can be spread by the wind. Dried flower stalks and seeds can remain on the plant for up to 2 years, and the stalks easily break off and spread in the landscape. Seeds also mix with soil and can be transported in clothing, equipment or vehicles. Root fragments can create new plants, so improper plant disposal could also help spread Dalmatian Toadflax.

Dalmatian Toadflax is found in the Sea to Sky region and its distribution is beyond landscape-level control. When Dalmatian Toadflax is present at high-priority locations and negatively impacting them, their control is considered a high priority.

Otherwise, the goal is to prevent it from spreading to new (uninfested) areas, and to control it where possible to limit its impact on biodiversity.

Learn to identify Dalmatian Toadflax: use the images presented in this profile page to learn how to identify this plant.

What to do if you spot it: You can report any sighting by visiting our reporting page..

 

DO:

• Regularly monitor properties for infestations.
• Avoid planting Dalmatian Toadflax
• Ensure soil and gravel are uncontaminated before transport
• Remove plant material from any equipment, vehicles, or clothing used in infested areas and wash equipment and vehicles at designated cleaning sites before leaving these areas.
• Minimize soil disturbances (e.g. use grazing plans that prevent soil exposure from overgrazing), and use seed mixes with dense, early colonization (e.g. alfalfa or barley) to re-vegetate exposed soil and resist invasion.
• Ensure plants (particularly flowering heads or root fragments) are bagged or covered to prevent spread during transport to designated disposal sites (e.g. landfill).

DO NOT:

• Don’t unload, park, or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles, or clothing used in such areas, and wash equipment and vehicles before leaving infested areas.
• Do not plant Dalmatian Toadflax, no matter how well-contained the area might seem.
• DO NOT COMPOST!

 

Control

Mechanical

• Hand-pull new and small infestations before the plants set seed, if the soil is not too hard or rocky.
• Remove as much of the root system as possible, as new shoots will re-sprout from any remaining lateral roots.
• In the case of more mature infestations, mechanical control must be repeated annually for at least 10 years to exhaust the seed bank.
• Mowing is only effective to diminish seed production, but not to control the plant.

Chemical

• Dalmatian Toadflax’s waxy leaves make the use of an oil or silicon-based surfactant necessary.
• Satisfactory control can be achieved using dicamba; chlorsulphuron, glyphosate or imazapyr have also proven effective.
• Picloram can be effective, but it is not suitable for wet, coastal soils.
• We recommend that any herbicide application is carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.

Biological

• Several biocontrol agents have been released in BC, most notably Mecinus janthinus, a black stem-boring weevil.
• Calophasia lunula, a moth, as well as Rhinusa antirrhini, another weevil, are also known biocontrol agents.