Dalmatian Toadflax

Dalmatian Toadflax

Linaria dalmatica

Information Sheet (PDF)

Colorado List B - Control required in Jefferson County

General

• Family: Plantaginaceae (Plantain)
• Grows from sea level to 9,200 feet
• Has been used as an ornamental but no longer available in Colorado
• Herbaceous perennial
• 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
• Prefers open, sunny locations
• Tolerant to low temperatures and coarse soils

Plant

Vegetation

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

Roots

• 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
• Taproots can reach 6 plus feet deep

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

• View Information Sheet (PDF)

Cultural

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

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. No specific recommendation or endorsement is made or implied by listing methods or products.