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Toadflax

Toadflax is a perennial that can carry harmful plant diseases while suppressing natural vegetation.

Toadflax plant
photo: Utah State University Archive

What you can do to stop the spread of toadflax

  • Avoid planting toadflax and avoid wildflower seed mixes as they might contain this harmful plant. Seedling toadflax plants are weak competitors, so maintaining a healthy garden and/or mulching between plants will inhibit Toadflax seedlings.
  • Toadflax can easily re-sprout from roots, so mechanical removal of plants (i.e. hand pulling, cutting, tilling) will likely need to be repeated for several years.
  • Cutting plants or mowing large patches during the early flowering stage will prevent seeding, but will only stress (not kill) plants.
  • Chemicals applied to toadflax may have limited impact, since the waxy texture of leaves and stems may prevent uptake of herbicide.
Dalmatian toadflax foliage
photo: Linda Wilson, University of Idaho

What is toadflax?

Plant Type: perennial
Size: up to 1.5m tall, single stem or bushy
Leaves: waxy, alternate along stem, heart shaped (L. dalmatica) or blade-like (L. vulgaris)
Flowers: Showy yellow snapdragon flowers with a spur on flower spikes, blooms May – June

Toadflax plants spread through both seed production and creeping roots - Roots penetrate up to 2 metres in soil and can spread 3 metres horizontally. Toadflax can harbour plant diseases and rapidly chokes out natural plant communities.

Toadflax is also known as Linaria dalmatica: Dalmatian Toadflax, Broadleaf Toadflax, Smooth Toadflax, Wild Snapdragon, Yellow Toadflax, Butter-and-eggs, Linaria spp. (Linaria dalmatica, Linaria vulgaris)

Consider some of these garden selections as alternatives to the toadflax

  • Fine-leaved goldenrod (Solidago graminifolia)
  • Goldenrod (Solidago canadensis)
  • Annual snapdragon (Antirrhinum majus)
  • Dwarf snapdragons (Chaenorrhimun minus)
  • Mountain goldenbanner (Thermopsis montana)

Yellow toadflax flowers and foliage

More information

Learn more about The City's initiatives to prevent invasive plant infestations.

View the fact sheets on invasive species in Alberta from the Alberta Invasive Plants Council.