It is a biennial, meaning it lives for two years.

Does it spread easily?

Yes, it produces thousands of seeds that germinate readily in disturbed soil.

Plant guide

Great Mullein.

Verbascum thapsus

Pronounced ver-BASS-kum THAP-sus

Also known as Aaron's rod, Aaron's-rod, Big Taper, Blanketweed, Charmin of the woods, Common Mullein, Flannel Mullein, Flannel Plant

Verbascum thapsus — Photo by Irina Mitine (CC BY) via gbif

Mullein is a striking biennial plant that produces a tall, impressive spike of yellow flowers. It's often found growing in fields and along roadsides where it enjoys plenty of sun. You'll love how its fuzzy, silver-green leaves add a unique texture to your garden.

Another photo of Great Mullein — Photo by mar (CC BY-SA) via iNaturalist

At a glance

Care level: Easy
Plant type: Biennial herb
Light: Full sun
Indoor light: Direct sun
Water: Every 7 to 14 days
Mature size: 6 to 8 feet
Growth rate: Fast
Hardiness: USDA 3 to 9
Bloom time: Mid to late summer

Care

Plant this in a spot that gets plenty of sunshine to keep it happy. Watch for wilting leaves during dry spells, which is your sign that it needs a good drink. It's a very low-maintenance plant that mostly takes care of itself once it's settled in.

Watering: Water deeply when the top inch of soil feels dry to the touch.
Feeding: It rarely needs fertilizer if planted in decent garden soil.
Pruning: Cut back the flower stalk after it finishes blooming to keep the area tidy.
Repotting: Since it's a biennial, you likely won't need to repot it before it completes its life cycle.
Soil: Well-draining, sandy or rocky soil
Soil pH: 6.0 to 7.5
Temperature: -40 to 35°C
Humidity: 30 to 70%
Drought tolerance: High
Lifespan: Biennial, typically 2 years.
Fragrance: Light
Deer and rabbits: High

Signs it needs repotting

Roots growing out of the drainage holes.
Stunted growth despite adequate light and water.

Safety

People: The plant is generally considered non-toxic, though the fine hairs on the leaves can cause mechanical irritation.
Children: The fine, fuzzy hairs on the leaves may cause irritation if handled by children, and the seeds should not be eaten.
Contact allergens: The dense, stellate hairs on the leaves can cause contact dermatitis or skin irritation in sensitive individuals.
Airborne allergens: The pollen can be a minor respiratory irritant for those with severe hay fever.
Edibility: While often used in herbal teas, the seeds contain rotenone and should not be ingested.

How to identify it

Tall central flowering spike
Soft, woolly, silver-green leaves
Large basal rosette of leaves
Small yellow five-petaled flowers

Height: 0.6 to 2m
Spread: 0.3 to 0.6m
Leaves: gray-green, semi-evergreen
Flowers: yellow, 1 to 3cm

Problems to watch for

Powdery MildewCommon
Leaf SpotUncommon
Root RotUncommon
Slugs and SnailsUncommon

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: spring, autumn
Overwintering: The first-year rosette stays low to the ground and remains evergreen in mild climates. No special protection is needed as it is very cold hardy.
In containers: It is not ideal for containers due to its long taproot, but it can grow in a very deep pot of at least 40 centimeters.

Direct Sowing

1. Collect seeds in late summer or autumn.
2. Scatter seeds onto bare, disturbed soil in a sunny location.
3. Press them lightly into the surface without burying them, as they need light to germinate.

Pair this plant with other sun-loving, drought-tolerant wildflowers to create a low-maintenance meadow aesthetic.

Grows well with

Purple Coneflower · They share similar requirements for full sun and well drained soil.
Black-eyed Susan · Both plants thrive in open, sunny meadows and disturbed ground.

Similar species

Moth Mullein · A related species with similar growth habits and flower structure.

Science

Family: Scrophulariaceae
Genus: Verbascum
Order: Lamiales
Class: Magnoliopsida
Native range: Europe, Northern Africa, and Asia.
Conservation: It is considered an invasive weed in many parts of North America and is not of conservation concern.

It is a pioneer species that thrives in disturbed, sunny, and dry soils where competition from other plants is low.

Value to wildlife: nectar source
Pollinators: bees, butterflies
Uses: ornamental, medicinal, erosion control

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 6/9
Light: 8/9
Temperature: 5/9
Moisture: 3/9
Nutrients: 3/9

Taxonomy resolved against GBIF.

Questions people ask

Is it a perennial?: It is a biennial, meaning it lives for two years.
Does it spread easily?: Yes, it produces thousands of seeds that germinate readily in disturbed soil.

Where the name comes from

The genus name Verbascum is a Latin corruption of barbascum, meaning bearded, while the species name thapsus refers to the ancient city of Thapsus in Tunisia.

Good to know

It is often called cowboy toilet paper due to the soft, fuzzy texture of its leaves.
The plant is a biennial, forming a rosette in its first year and a tall flower spike in its second.
It was historically used as a torch by dipping the dried stalk in tallow.

Also in

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This guide was generated with AI on September 26, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.