Overview
Phlomis tuberosa is a perennial, shrub perennial herbaceous in the genus Phlomis, part of the Lamiaceae family, with sage-like foliage. It typically grows around 1.5 m tall. Phlomis tuberosa grows best in full sun, and tolerates most soils and neutral pH. Its UK hardiness is rated H7. Suggested uses include border, rock garden and drought-tolerant planting. It is native to China, Kazakhstan, Kyrgyzstan, Mongolia, Russia, south west Asia and Europe.
About
Phlomis tuberosa is a perennial herbaceous plant that sends erect stems to about 1.5 m from enlarged tuberous roots. It bears spikes of purple-red flowers that open from June to August. Plant in full sun on well-drained ground and avoid waterlogged sites; it tolerates sandy, loamy or clay soils and is fully hardy in the UK (H7).
Wikipedia contributors, CC BY-SA 4.0 — Phlomoides tuberosa
About the genus
Phlomis is a genus of over 100 species of herbaceous plants, subshrubs and shrubs in the mint family Lamiaceae, native from the Mediterranean region east across central Asia to China.
Wikipedia contributors, "Phlomis", CC BY-SA 4.0 — Phlomis
In the garden
Phlomis tuberosa, known as sage-leaf mullein, is a herbaceous perennial native across parts of Europe and Asia, including China, Kazakhstan, Kyrgyzstan, Mongolia, Russia and south west Asia. The plant rises from swollen, tuberous roots to produce upright stems topped with whorls of purple-red flowers that appear from June to August, giving it a clear summer presence. Give it a sunny, open position; the species prefers full sun and performs well in sandy, loamy or clay soils provided they are well drained or at least moist but not waterlogged. It carries a UK hardiness rating of H7, meaning it will withstand the coldest UK winters, and it is suited to USDA zones 5-9. Avoid heavy compaction around the crown so the tuberous roots can develop. At about 1.5 m tall, Phlomis tuberosa suits the middle to back of a herbaceous border or a sunny gravel bed where its vertical stems can be appreciated. Allow space for the upright habit so the flower spikes remain visible through summer. The combination of tuberous roots and tall, flower-crowned stems makes it a distinct structural plant for midsummer colour between June and August.
Growing conditions
Best soil and position for Phlomis
- Sunlight
- Full sun
- Soil type
- Sandy, Loamy, Clay
- Soil pH
- Neutral
- Soil moisture
- Well-drained, Moist but well-drained
- Aspect
- South-facing
- Exposure
- Full sun
- UK hardiness
- H7
Plant details
Phlomis tuberosa size, habit and characteristics
- Plant type
- perennial herbaceous
- Habit
- Perennial, Shrub
- Foliage
- Sage-like
- Height
- 1.5 m
- Suggested uses
- Border, Rock garden, Drought-tolerant planting
- Native to
- China, Kazakhstan, Kyrgyzstan, Mongolia, Russia, south west Asia, Europe
Care notes
Pruning and caring for Phlomis tuberosa
- Cultivation
- Prefers full sun and well-drained soil; drought tolerant once established; avoid waterlogged conditions; can be propagated by seed or semi-ripe cuttings.
- Pruning
- Cut back old flowering stems after blooming to encourage fresh growth.
- Propagation
- Seed, Semi-ripe cuttings
- Pest resistance
- Generally pest-free
- Disease resistance
- Generally disease-free
Frequently asked questions
How do I grow Phlomis tuberosa?
Prefers full sun and well-drained soil; drought tolerant once established; avoid waterlogged conditions; can be propagated by seed or semi-ripe cuttings.
Where is the best place to plant Phlomis tuberosa?
Phlomis tuberosa prefers full sun. It suits full sun positions.
What soil does Phlomis tuberosa need?
Phlomis tuberosa is adaptable and grows happily in most soil types, including sandy, loamy and clay. It prefers neutral soil. Aim for soil that stays well-drained to moist but well-drained.
How do I prune Phlomis tuberosa?
Cut back old flowering stems after blooming to encourage fresh growth.
How big does Phlomis tuberosa grow?
Phlomis tuberosa reaches a height of 1.5 m.
Is Phlomis tuberosa hardy in the UK?
Phlomis tuberosa has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.
How do I propagate Phlomis tuberosa?
Seed, Semi-ripe cuttings.
More in the Phlomis genus
Browse all Phlomis →
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