Mullein (Verbascum thapsus) is a distinctive biennial plant, recognized by its tall flower stalks and soft, woolly leaves. It frequently grows in disturbed soils, adding unique texture to landscapes. Beyond aesthetics, mullein has a history in traditional herbal practices and provides ecological benefits, attracting pollinators.
Understanding Mullein Propagation Methods
Stem cuttings are often considered for mullein. However, mullein is challenging to propagate from stem cuttings. Its growth habit and lack of nodal roots make this method impractical due to low success.
While stem cuttings are not viable, mullein can be propagated vegetatively using root cuttings. This method uses the plant’s robust root system, yielding new plants from sections. While root cuttings are possible, growing mullein from seed is the most common and successful.
Propagating Mullein from Root Cuttings
Root cuttings offer a reliable way to propagate mullein. Take root cuttings during the plant’s dormant season, typically late autumn after foliage dies back or early spring before new growth. This minimizes stress, using stored root energy.
Carefully dig around a mature mullein plant, exposing a healthy taproot. Select a pencil-sized section of the taproot or a lateral root. Using a sharp knife or pruners, cut root sections 2-4 inches long.
Make a straight cut on the end closest to the parent plant and a slanted cut on the farthest end. This helps remember correct planting orientation (straight-cut end upwards). Prepare a well-draining rooting medium, such as perlite, peat moss, or sandy mix.
Plant each root section horizontally or with the straight-cut end slightly elevated, burying it 0.5-1 inch deep. Keep the medium consistently moist, not waterlogged, to prevent rot. Place containers in a cool location (40-50°F) with indirect light to encourage root development.
Propagating Mullein from Seed
Growing mullein from seed is the easiest and most successful method, yielding many plants. Seeds can be collected from dried stalks of mature plants or purchased from suppliers. Wild mullein seeds benefit from cold stratification to break dormancy and improve germination.
To stratify, mix seeds with moist sand or peat moss and refrigerate for four to six weeks. This mimics winter to prepare seeds for germination. When sowing, mullein seeds require light for germination, so surface-sow them directly onto a well-draining seed-starting mix. Gently press seeds into the surface; do not cover.
Keep the seed-starting medium consistently moist, using a fine mist or bottom watering to prevent dislodging. Ideal germination temperatures are 65-75°F. Germination occurs within one to three weeks.
Caring for Young Mullein Plants
Once seedlings have a few true leaves or root cuttings show new top growth, they are ready for transplanting. Handle young plants carefully to avoid root damage. Transplant them into small pots or directly outdoors.
Mullein thrives in full sun, needing 6-8 hours of direct sunlight daily for optimal growth. It prefers well-draining soil and tolerates various soil types, including poor or rocky, unless waterlogged. Avoid heavy, moisture-retaining clay.
During establishment, young mullein plants need consistent watering for robust root development. Once established, mullein is drought-tolerant and only needs supplemental watering during dry periods. General maintenance involves adequate air circulation and monitoring for pests or diseases; it is resilient.