Great mullein

Sun

Full sun.

Water

Low once established; water young plants during prolonged dry spells and avoid persistently wet soil.

Soil

Well-drained, preferably lean soil, including sandy, gravelly or chalky ground. Avoid heavy, waterlogged soil.

Height

3-7 ft (0.9-2.1 m)

Spread

1-2 ft (0.3-0.6 m)

Flowers

Summer into early autumn; small yellow flowers open successively along a tall, dense spike.

Foliage

Evergreen. Large, softly felted, grey-green leaves form a basal rosette, with smaller leaves clasping and extending down the flowering stem. Rosettes often retain leaves through winter but may lose foliage in severe cold.

Growth

Fast; usually flowers in its second summer, though flowering can be delayed in poor conditions.

Care needed

Low

• Pollinators
• Deer resistant
• Drought tolerant
• Cold hardy
• Heat tolerant
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   3 ft (0.92 m)

3. After 2 years

   5 ft (1.5 m)

   full size

About 2 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Native to

the UK

Invasive in

the US, Canada and Australia

In the garden

Spreads vigorously: plan to contain it.

Growth rate

Fast

• Plant in full sun with excellent drainage.
• Water new rosettes until established; thereafter water only during extended drought.
• Do not routinely feed; rich soil encourages oversized, less sturdy growth.
• Keep mulch away from the crown and avoid moisture-retaining mulch on damp sites.
• Thin unwanted seedlings while small, before their taproots develop.

Pruning. Cut flowering stalks off at the base before seed capsules ripen to limit spread. Remove the dying rosette after flowering; wear gloves if the leaf hairs irritate your skin.

Early spring

Check overwintered rosettes and remove plants with rotten crowns.

Spring

Where growing it is appropriate, surface-sow seed on open, well-drained soil and thin seedlings.

Late spring

Remove unwanted seedlings and stake unusually exposed flowering stems if necessary.

Summer

Water establishing plants during dry spells; established plants usually need little attention.

Late summer

Cut flower spikes before capsules ripen unless limited self-seeding is wanted and locally appropriate.

Autumn

Remove spent plants and keep fallen leaves from smothering young rosettes.

• Use occasional plants as vertical accents among low plants in a sunny gravel garden.
• Pair the silver rosettes with lavender and catmint for contrasting leaf shapes.
• Place behind shorter cottage-garden flowers to add height without a broad canopy.
• Use in a managed pollinator border within its native range, removing excess seedlings.

Garden styles it suits: Cottage garden, Dry gravel garden, Desert / xeriscape, Pollinator garden, Architectural minimal and Mediterranean.

Plant it with: Lavender, Catmint, Yarrow, Sea holly, Stonecrop and Lamb's ears.

Wildlife: Flowers provide pollen for bees. In Britain, the foliage feeds mullein moth caterpillars. Its wildlife value outside its native range does not outweigh the need to control invasive spread.

• Crown or root rot in wet ground: improve drainage or move young plants to a drier site; discard rotting plants.
• Powdery mildew: provide full sun and airflow, and remove badly affected foliage.
• Mullein moth caterpillars, especially in the UK: tolerate some feeding for wildlife, or hand-pick if a small plant is being stripped.
• Excessive self-seeding: remove spikes before seed ripens and pull seedlings promptly; avoid disturbing soil unnecessarily.

Not generally known to be poisonous to cats, dogs or horses, but species-specific safety information is limited. Leaf hairs can irritate people's skin, mouth and throat, and seeds contain rotenone and should not be eaten. Keep children and pets from chewing the plant, and seek medical or veterinary advice after significant ingestion.

Where it spreads. Introduced and aggressively self-seeding in disturbed ground across much of North America and parts of Australia. It is listed as invasive in parts of the western United States and British Columbia, Canada, and is an environmental weed in southeastern Australia, including Victoria and Tasmania. Check local weed guidance before planting; seed can remain viable in soil for decades.

• Common foxglove (Digitalis purpurea)

  Young foxgloves also form hairy rosettes, but their leaves are greener, more wrinkled and toothed. Flowers are large hanging bells rather than small, open yellow flowers; foxglove is highly poisonous.

• Moth mullein (Verbascum blattaria)

  Leaves are green and mostly hairless rather than densely woolly, and yellow or white flowers are spaced loosely along slender stems.

• Orange mullein (Verbascum phlomoides)

  It has similarly woolly leaves but generally larger yellow flowers; its upper leaves do not extend down the stem to form the conspicuous wings typical of great mullein.

The common name mullein is generally traced to a word meaning soft, referring to the felted leaves, while great distinguishes this tall species from smaller mulleins.

Propagation. Propagate by seed in spring or late summer where local guidance permits. Press seed onto the surface because it needs light to germinate, and transplant seedlings while small to avoid disturbing the taproot. It is not normally divided.

Accepted botanical name

Verbascum thapsus

In the US and Canada

Introduced in Alaska, Canada, Hawaii and the lower 48 states.

Native range

Afghanistan, Altay, Austria, Azores, Baleares, Baltic States, Belarus, Belgium, Central European Rus, China South-Central, Corse and Czechoslovakia.

Measured

Soil pH 7 to 7.5. Average height 82 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.