Almost every part of the mullein plant is usable: leaves, flowers, and roots each have distinct traditional applications. The leaves are the most commonly used part, typically brewed into tea for respiratory support, while the flowers are prized for infused ear oils, and the roots see more niche use. Which part you want depends on what you’re using it for.
Leaves: The Most Popular Part
Mullein leaves are the go-to for most people, especially anyone interested in respiratory support. They’ve been used traditionally for coughs, bronchitis, sore throats, colds, and asthma. The leaves contain natural compounds that act as anti-inflammatories, which likely explains their long history of use for conditions involving irritated airways. Lab studies have confirmed that water-based mullein extracts can inhibit the growth of bacteria involved in respiratory infections, making a simple tea one of the more effective preparations.
The leaves also contain mucilage, a gel-like substance that coats and soothes irritated mucous membranes in the throat and lungs. This is why mullein tea often feels soothing on a raw throat, even before any deeper anti-inflammatory effects kick in.
A typical dose is 4 to 8 ounces of mullein leaf tea, two to four times daily. Steep a single tea bag or about a tablespoon of dried leaf for 3 to 5 minutes. One critical step: always strain mullein tea through a fine cloth or coffee filter. The leaves are covered in tiny fuzzy hairs (visible to the naked eye as that signature velvety texture), and those hairs can irritate your throat if they end up in your cup.
Flowers: Best for Ear Oil
Mullein’s small yellow flowers are the part traditionally used for earaches. They’re infused into olive oil over several weeks to create a gentle remedy for ear infections in both adults and children. Some traditional recipes combine mullein flowers with garlic in the olive oil base to boost the pain-relieving and antimicrobial effects.
Making flower oil is straightforward: pack fresh or slightly wilted flowers into a jar, cover completely with olive oil, and let the jar sit in a sunny window for two to three weeks, shaking occasionally. Strain thoroughly before use. A few drops of the warmed (not hot) oil go directly into the affected ear.
Two important cautions with ear oil. Never add potent essential oils like tea tree oil to the preparation, as they’re too strong for the delicate ear canal. And if you suspect a ruptured eardrum or aren’t sure what’s causing the ear pain, skip the oil entirely. Oil inside the ear can make it harder for a doctor to see the eardrum clearly.
Roots: Less Common but Still Used
Mullein root is the least widely used part, but it has a place in traditional herbalism. It’s been prepared as a decoction (simmered in water rather than steeped) for urinary tract support and joint pain. Because the root is denser than the leaves or flowers, it requires longer extraction times to pull out its active compounds. Most people working with mullein will never need the root, but foragers and serious herbalists sometimes harvest it at the end of the plant’s first year, when the root is still fleshy and hasn’t yet put its energy into the flower stalk.
When to Harvest Each Part
Mullein is a biennial, meaning it lives for two years. In its first year, it grows only a low rosette of large, fuzzy leaves close to the ground. In the second year, it sends up a dramatic flower stalk that can reach 2 to 8 feet tall.
Leaves can be harvested throughout most of the growing cycle, including during flowering in the second year. First-year rosette leaves are often preferred because they’re large, vigorous, and the plant hasn’t yet diverted energy into reproduction. Larger leaves can be tricky to dry evenly, so splitting them or using a dehydrator helps prevent mold.
Flowers appear only in the second year and bloom progressively up the stalk over several weeks during summer. Pick them when they’re freshly open and bright yellow. They’re small and delicate, so harvesting enough for a batch of oil takes patience and multiple visits to the plant.
Roots are best dug at the end of the first growing season or very early in the second spring, before the flower stalk emerges and the root becomes woody.
Identifying the Right Plant
The species you want is common mullein (Verbascum thapsus), which is widespread across North America, Europe, and parts of Africa. It’s easy to identify once you know what to look for. First-year plants form a ground-level rosette of thick, pale green leaves covered on both sides with soft, woolly hairs that feel like felt. The leaves can be anywhere from 3 to 20 inches long, with lower leaves noticeably larger than upper ones.
In the second year, the flower stalk is unmistakable: a single tall, densely packed spike of yellow flowers, each about half an inch to an inch across with five petals. The flowers crowd so tightly along the stalk that you can barely see the stem beneath them. A similar species, moth mullein (Verbascum blattaria), has much sparser flowers with visible gaps between them and branched hairs instead of the simple woolly fuzz of common mullein.
Safety Considerations
Mullein leaf is generally regarded as safe, with no well-established drug interactions. The most commonly reported side effect is contact dermatitis (an itchy rash) in people who are allergic to the plant. Some research has linked mullein to potential kidney stress, so people with existing kidney disease should be cautious.
Mullein seeds are considered potentially toxic and are not used medicinally. If you’re harvesting your own plant material, keep the seeds out of your preparations. When buying commercial mullein products, choose reputable brands that are less likely to have seed contamination.
People who are pregnant or breastfeeding should avoid mullein, as there’s no established safety data for these groups.