Verbascum, commonly known as mullein, is a biennial herbaceous plant with a characteristic spike or cone of yellow flowers, which can be used as a dye. It is also called big taper, common mullein, flannel plant, velvet dock, velvet plant, and woolly mullein. It originated in Europe and Asia, and was brought to the United States by settlers.
Mullein is native to Europe and Asia, and was brought to the United States by settlers. It has been used as a medicinal plant for cough, diarrhea and to stimulate respiration. It has had other uses over the years and has become widespread throughout the United States due to these uses. It was used as a piscicide, or fish poison, early in the 1700s, in Virginia. Botanists catalogued it in Michigan, and along the Pacific Coast in the 1800s, documenting its quick spread. Methanol can be extracted from mullein, and is sometimes used as an insecticide for mosquito larvae.
Verbascum is cold hardy, due to its biennial dieback, and will renew itself in the spring. It is found naturally in every state of the United States and most Canadian provinces except the sub-Arctic regions. In warm areas, it can become invasive; in Hawaii it is listed as a noxious weed that is alien to native plants. Other temperate climate states also count it as an invasive weed, including Colorado, California, Kentucky, Nebraska, Tennessee and Wyoming.
Seeds of verbascum are small, but tough, and can be kept for several years before germination. They can be planted any time of year, but will sprout in the spring. Mullein needs a growing season of about four months to seed itself and thrive. Seeds prefer shallow soil coverage to germinate, and do best in raked or loosened soil.
An individual mullein plant blooms every two years. If you have more than one plant, they may not be on the same blooming cycle. In verbascum's first year, it will produce a rose shape of leaves without flowers, which are grayish-green and low to the ground, no higher than a foot. In its second year, it grows much taller, up to 5-10 feet, and produces the flowering stalk. It will bloom from June to August, and seed itself in late summer and early fall.
Mullein does not like shade and grows best in full sun. It can tolerate dry soils, and only needs from three to six inches of rain in a growing season. It also prefers well-drained and even sandy soils. It will suffer and even die in wet soils. Soil for verbascum should have a neutral pH or be slightly alkaline.