Phlomis tuberosa (Tuberous Jerusalem sage) — perennial herbaceous

Overview

Phlomis tuberosa is a perennial herbaceous in the genus Phlomis, part of the Q53476 family. It typically grows around 1.5 m tall. Phlomis tuberosa grows best in full sun, and tolerates most soils. Its UK hardiness is rated H7. 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 moisture: Well-drained, Moist but well-drained
Exposure: Full sun
UK hardiness: H7

Plant details

Phlomis tuberosa size, habit and characteristics

Plant type: perennial herbaceous
Height: 1.5 m
Native to: China, Kazakhstan, Kyrgyzstan, Mongolia, Russia, south west Asia, Europe

Frequently asked questions

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. Aim for soil that stays well-drained to moist but well-drained.