The Mullein plant (Verbascum thapsus) is a widely recognized biennial species across North America and Europe. Its life span stretches over two growing seasons, during which its appearance changes significantly. Understanding these two distinct phases is key to identifying Mullein. This guide describes the plant’s form during its first and second years of growth, along with its preferred habitats.
First-Year Growth: The Basal Rosette
Mullein begins its life as a low-growing, compact arrangement of leaves known as a basal rosette, designed to gather sunlight and store energy. This rosette typically lies flat against the soil surface, sometimes reaching up to 30 inches in diameter by the end of the first season.
The leaves are oblong to lanceolate, often measuring between 4 and 15 inches long. They are characterized by a dense covering of soft, woolly, star-shaped hairs on both sides. This heavy coating gives the leaves a silvery-green or grayish-green color and a flannel-like texture, leading to the common name “flannel plant.”
The rosette allows the plant to overwinter and protects its central growing point from cold temperatures. The leaves are attached close to the compressed stem, which remains near the soil surface until the following spring. Identification relies on recognizing the characteristic size and the unique soft, felt-like texture.
Second-Year Growth: The Flowering Spike
The second year, Mullein uses its stored energy to produce a single, stout, erect flowering stalk, or spike. This stalk emerges from the center of the first year’s rosette and commonly ranges from 3 to 7 feet tall.
The entire stalk remains densely hairy, maintaining the woolly texture of the basal leaves. Along this sturdy, unbranched stem are smaller, alternating leaves that are stalkless and appear to clasp the stalk, giving it a “winged” appearance. These leaves decrease in size toward the top of the plant.
The upper portion of the stalk is topped with a dense, elongated cluster of flowers. The flowers are small, saucer-shaped, and typically bright yellow, though occasionally they can be white. Each flower has five rounded petals and is less than an inch across. They bloom sequentially, moving up the spike from early summer into autumn.
Common Habitats and Range
Mullein is an opportunistic plant that has naturalized across North America, Europe, and Asia, having been introduced to the Americas in the 18th century. It prefers environments where other vegetation is sparse, making it a colonizer of disturbed ground.
The plant thrives in open, sunny locations with well-drained soil and shows a high tolerance for poor or dry conditions. Common locations include roadsides, abandoned fields, gravel areas, pastures, and forest clearings. Because it requires full sun, Mullein is rarely found in heavily shaded areas. Its presence often indicates that the soil has been recently disturbed.