An erect summer annual with alternate, lanceolate leaves that have toothed margins. Fireweed is primarily a weed of pastures, abandoned fields, and some agronomic crops. Its leaves are elliptic to lanceolate in outline, approximately 2 to 8 inches long, and 1/2 to 1/2 inches wide. Their stems are erect, solid, and usually without hairs (though occasionally slightly hairy). Stems range from 1 1/3 to 10 feet in height. This weed grows in the thatch layer which is located above the pre-emergence controls, rendering such controls powerless to stop its growth. Soil deficiencies indicated by this weed include low calcium and phosphorous, high potassium and iron, and excess thatch. Correcting these deficiencies is the most effective way to prevent this weed from growing.