Yellow toadflax is a member of the snapdragon family and is easily recognized by the bright yellow flowers. It was introduced as an ornamental in the mid-1800's known as Butter-n-Eggs, wild snapdragon, common toadflax, ramsted, flaxweed and Jacob's ladder. Many of the old homesteads had Yellow toadflax planted around the farmstead. Since then it has escaped and has become very invasive. Yellow toadflax is becoming a major problem in many counties across North Dakota and has just recently been added to the North Dakota noxious weed list.
Yellow toadflax grows from 1 to 2 feet tall and can be confused with Leafy spurge as the leaf shape is similar; long and narrow. However, toadflax does not exude the white plant sap that Leafy spurge does when the stem or leaf is broken. Reproduction is by seed or by underground rootstocks similar to Dalmatian toadflax. A single plant may produce up to 500,000 seeds that are dispersed by wind, rain, wildlife and movement of forage and livestock. The roots of a single plant can extend up to 10 feet and produce daughter plants every few inches.
Yellow toadflax is aggressive and displaces native and tame forages. It is adapted to more moist soils and is often found in pasture, meadows and ditches. Yellow toadflax can be mildly toxic to livestock.
Control is difficult as few herbicides are effective. Picloram with Overdrive applied in mid-summer during flowering or in late fall will reduce infestations.