Oldfield toadflax (Nuttallanthus canadensis) is also known as common or blue toadflax. It is a winter annual or biennial weed that is commonly found blooming in the spring in fields and roadsides. Oldfield toadflax is most often found in the Piedmont and Coastal Plain of North Carolina. The plant can flower from early spring (most common) to late fall (less common) - depending on growing conditions. The small blue flowers have three lobes and basal spurs. The leaves are small, bright green and linear. Small clumps of leaves will form in early spring, and the blue flowers will appear on long green stems shortly thereafter.

Proper turf management is important for biennial broadleaf weed control. Maintain a dense, actively growing turf through proper mowing, fertilizing, and watering practices. Mow at the proper height for your selected adapted turfgrass. Coring and traffic control reduce compaction and encourage desirable turfgrass competition. It is best to control this biennial broadleaf weed in spring or fall, if actively growing at these times.

• GROWTH SEASON / LIFE CYCLE
  • winter annual weed or biennial weed
• GROWTH HABIT
  • upright
    Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6
• LEAFLET NUMBER
  • one
• LEAF MARGIN
  • smooth
• LEAF HAIRS
  • none
• LEAF / LEAFLET SHAPE
  • linear / oblong
• LEAF WIDTH
  • <1/2 inch
    Figure 7
• LEAF ARRANGEMENT
  • alternate
• FLOWER COLOR
  • blue / purple
    Figure 8, Figure 9, Figure 10, Figure 11, Figure 12

Figure 1. Oldfield toadflax growth habit.

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Figure 1. Oldfield toadflax growth habit.

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Figure 2. Oldfield toadflax growth habit.

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Figure 2. Oldfield toadflax growth habit.

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Figure 3. Oldfield toadflax growth habit.

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Figure 3. Oldfield toadflax growth habit.

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Figure 4. Oldfield toadflax growth habit.

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Figure 4. Oldfield toadflax growth habit.

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Figure 5. Oldfield toadflax growth habit.

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Figure 5. Oldfield toadflax growth habit.

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Figure 6. Oldfield toadflax growth habit.

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Figure 6. Oldfield toadflax growth habit.

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Figure 7. Oldfield toadflax leaf width.

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Figure 7. Oldfield toadflax leaf width.

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Figure 8. Oldfield toadflax flower color.

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Figure 8. Oldfield toadflax flower color.

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Figure 9. Oldfield toadflax flower color.

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Figure 9. Oldfield toadflax flower color.

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Figure 10. Oldfield toadflax flower color.

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Figure 10. Oldfield toadflax flower color.

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Figure 11. Oldfield toadflax flower color.

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Figure 11. Oldfield toadflax flower color.

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Figure 12. Oldfield toadflax flower color.

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Figure 12. Oldfield toadflax flower color.

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