About Mullein
Mullein, also known as verbascum, is a striking vertical bloomer that produces tall spires of soft, nectar-rich flowers in shades of yellow, pink, purple, and white. Easy to grow from seed, it thrives in poor soils and sunny, dry conditions where many other plants struggle. With its graceful architecture and pollinator appeal, mullein adds both resilience and elegance to cottage gardens or wildflower planting.
Consider pairing verbascum with sun-loving, drought-tolerant perennials and airy textures: Salvia, Nepeta, Lavandula, Achillea, and ornamental grasses. These companions echo Verbascum’s preference for drainage and sun while extending seasonal interest.
When to Plant Mullein Seeds
Spring Sowing (All Zones): Start seeds indoors 8 to 12 weeks before the last frost. Harden off and transplant outside after frost, once night temperatures are consistently above 45°F to 50°F.
Autumn Sowing (Mild Zones): In areas with mild winters, fall sow outdoors or set out young seedlings in early fall. Plants establish roots through winter and bloom earlier the following spring. Choose a location with reliable drainage where it can be protected from prolonged saturation.
Where to Plant Mullein Seeds
Choose a location in full sun, receiving six to eight-plus hours of sunlight daily. Well-draining, average to lean soils are ideal. Mullein sends down a taproot, so sandy soil is preferred and clay, heavy, or wet sites are to be avoided. Good air circulation is essential, so choose open, sunny borders, alongside pathways, or even raised beds. You will want to witness these blooms up close, so plant them where the spires can be appreciated.
How to Plant Mullein Seeds
Mullein seeds germinate best when temperatures are around 65°F to 68°F. Surface-sow seeds or just lightly cover them with soil as seeds need light to germinate. Germination should occur anywhere between 3 to 14 days. Read more about light requirements here.
Keep seedlings in bright light with steady but moderate moisture and good air circulation. Avoid overwatering.
After all danger of frost has passed, begin to harden off seedlings once night temperatures are consistently above 45°F and 50°F. Set transplants out 12 to 20 inches apart to ensure good air flow and provide the largest floral impact. Read more about how to harden off seedlings here.
How to Care for Mullein
While mullein plants need water to establish themselves, their needs diminish as they mature. Once in the garden, provide deep, infrequent watering so as not to keep the plants consistently wet. A light fertilizer low in nitrogen can be applied.
Staking can help in rich soils or windy sites. Harvest when the lower third of florets are open. Deadhead spikes after all blooms have faded to not only keep the garden bed tidy, but to encourage a late-season rebloom.
Remember that mullein blooms shy away from summer heat. Maintain light care, and flowering will resume with cooler nights.
Mullein reseeds readily. To collect seeds, allow stalks to mature then store dried seed heads in a cool and dry location.