Olympian mullein Verbascum olympicum
Olympian mullein (Verbascum olympicum) is a biennial flowering plant in the Scrophulariaceae family, native to Uludağ (Mount Olympus of Bithynia), north-western Turkey. It grows 1.5–2 m (4.9–6.6 ft) tall and 60 cm–1 m (24 in–3.3 ft) wide, wants full sun and low water, and is hardy to about -20 °C (-4 °F). Space plants about 80 cm (31 in) apart.
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Olympian mullein at a glance
| Type | Biennial flowering plant |
|---|---|
| Family | Scrophulariaceae |
| Mature height | 1.5–2 m (4.9–6.6 ft) |
| Mature spread | 60 cm–1 m (24 in–3.3 ft) |
| Spacing | 80 cm (31 in) centre to centre |
| Sun | Full sun, at least 7 h of direct sun a day |
| Water | Low; drought tolerance high, waterlogging tolerance none |
| Soil pH | 6.5–8.5 |
| Cold hardiness | About -20 °C (-4 °F) once established (roughly USDA zone 6) |
| Heat stress | Likely above about 38 °C (100 °F) |
| Flowering | about 57–104 weeks after planting, for 6–9 weeks |
| Wind tolerance | Low |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | Uludağ (Mount Olympus of Bithynia), north-western Turkey |
| Common in gardens of | 🇹🇷 Turkey, 🇬🇷 Greece, 🇬🇧 United Kingdom, 🇩🇪 Germany, 🇳🇱 Netherlands, 🇫🇷 France |
Is Olympian mullein toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
Not poisonous; the woolly hairs can irritate skin.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Olympian mullein
No well-documented helpful pairing. Group it with plants that like full sun and low water.
Questions about Olympian mullein
- How far apart should I plant Olympian mullein?
- About 80 cm (31 in) apart, centre to centre. A mature plant spreads 60 cm–1 m (24 in–3.3 ft).
- Does Olympian mullein need full sun?
- Full sun: at least 7 hours of direct sun a day.
- How much water does Olympian mullein need?
- Low water. Drought tolerance is high and waterlogging tolerance none.
- How cold-hardy is Olympian mullein?
- It tolerates about -20 °C (-4 °F) once established, roughly USDA zone 6. As a biennial it is usually planted out after the last frost and flowers in its second year.
- When does Olympian mullein flower?
- About 57–104 weeks after planting, for 6–9 weeks.
- Is Olympian mullein poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Not poisonous; the woolly hairs can irritate skin.
- What grows well with Olympian mullein?
- There is no well-documented companion pairing for Olympian mullein. Group it with plants that like the same sun (full sun) and water (low).
Sources and evidence
Evidence grade A (A: strong evidence).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- RHS Find a Plant (plant profiles and growing guides), Royal Horticultural Society
Notes and assumptions
- A summer-dry plant: water it through its first summer, then rarely or never; it wants sun, lean soil and sharp drainage, and is killed by summer irrigation and heavy clay more often than by drought.
- A huge rosette of white-felted leaves in the first year, then a candelabra of branched spires of bright yellow flowers up to 2 m tall in the second summer. Often lives three years before flowering; self-seeds in gravel.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
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