Yellow toadflax—also called butter-and-eggs—looks cheerful with its snapdragon-like yellow flowers, but it’s a tough weed once it gets established. One mature plant can produce lots of seed and re-sprout from creeping roots, so a small patch can become a big problem fast. If you see it along roadsides, fields, or the edge of your lawn, act early.
Look for narrow, gray-green leaves on a square stem and clusters of tubular yellow flowers with an orange throat. Flowers bloom from late spring into fall. Plants grow 30–60 cm tall and often form loose clumps. Seeds are small and numerous; roots are fibrous and can form short, spreading rhizomes. That combination—many seeds plus persistent roots—is why it spreads so well.
Common ID mistakes: it can be confused with snapdragons or some native wildflowers, but toadflax leaves are more linear and the plant has that sticky, slightly hairy feel. If you’re unsure, check for the orange-spotted throat in the flower—that’s a reliable clue.
Pull or dig small patches when the soil is moist. Grab the crown and remove as much root as you can; any leftover root piece can resprout. For larger patches, repeat removal every 2–3 weeks through the season to stop new seed heads.
Mow or cut before plants set seed to reduce spread. Mowing won’t kill established roots, but it lowers seed production and makes follow-up control easier. If you mow, collect and bag clippings with seed heads—don’t leave them on the ground.
Spot herbicide treatments are often the fastest fix for big infestations. Systemic herbicides (like those with glyphosate or triclopyr) work best when plants are actively growing and moving sugars to the roots—late summer to early fall is a good time. Always read the label, follow local rules, and avoid spraying desirable plants nearby.
For pastures and native areas, consider an integrated approach: timed mowing, spot herbicide, and reseeding with competitive grasses or native wildflowers. That helps block re-establishment without wide herbicide use.
Dispose of pulled plants and seed heads by bagging and sending to landfill or by burning if allowed. Don’t compost seed-heavy material unless your compost reaches high temperatures consistently.
Prevention beats cleanup. Check seed mixes and soil brought onto your land, trim vehicle tires and equipment that move soil, and remove new plants as soon as you spot them. Planting competitive groundcovers or dense turf reduces places where toadflax can get a foothold.
People have used yellow toadflax in folk medicine, but that’s not a reason to encourage it in your yard. It can reduce forage quality in pastures and crowd out native flowers that pollinators rely on.
If a patch looks too big to handle or it’s in sensitive habitat, contact your local extension office or land manager. They can recommend the safest timing and products for your area. Quick action and consistent follow-up are the two best ways to win the fight against yellow toadflax.
