Overview
Thermopsis lanceolata is a herbaceous perennial in the genus Thermopsis, part of the Q44448 family. It typically grows around 1 metres tall. Thermopsis lanceolata grows best in full sun and partial shade, and tolerates well-drained and fertile soils. Its UK hardiness is rated H5. Suggested uses include borders and naturalized areas. It is native to Asia.
About
Thermopsis lanceolata is an herbaceous perennial that reaches about 1 metre and flowers in June to July with pale yellow blooms. It comes from Asia and suits positions in full sun or partial shade. Plant in fertile, moist but well-drained soil and allow room for its mature spread. Parts of the plant are harmful if eaten, so wear gloves when handling and keep away from pets.
Wikipedia contributors, CC BY-SA 4.0 — Thermopsis lanceolata
About the genus
Thermopsis is a genus of legumes, native to temperate North America and east Asia. They are herbaceous perennials and are known as goldenbanners or false-lupines.
Wikipedia contributors, "Thermopsis", CC BY-SA 4.0 — Thermopsis
In the garden
Thermopsis lanceolata is an herbaceous perennial native to Asia, growing to roughly 1 metre. It produces pale yellow flowers in June to July, offering a clear seasonal presence in the early summer border. Position this plant where it receives full sun or partial shade and where the soil is fertile and drains freely; it prefers moist yet well‑drained conditions rather than heavy, waterlogged ground. Rated H5 (hardy) for UK conditions, it withstands normal winter exposure across much of Britain when sited appropriately. Allow adequate space at planting for the mature height and habit; a 1 metre gap from other medium perennials avoids overcrowding. The species suits mixed herbaceous borders and naturalised drifts where a summer display of yellow will complement grasses and late-spring bulbs. Take care when handling: the plant is harmful if eaten, so wear gloves and keep it away from pets. For guidance and contact numbers regarding pet exposure, consult the HTA guide to potentially harmful plants. The clear June–July flowering window makes Thermopsis lanceolata a useful choice when planning summer colour sequences.
Growing conditions
Best soil and position for Thermopsis
- Sunlight
- full sun, partial shade
- Soil type
- well-drained, fertile
- Soil moisture
- moist, well-drained
- UK hardiness
- H5
Plant details
Thermopsis lanceolata size, habit and characteristics
- Plant type
- herbaceous perennial
- Height
- 1 metres
- Suggested uses
- borders, naturalized areas
- Native to
- Asia
- Toxicity
- Harmful if eaten. Wear gloves and other protective equipment when handling Pets (dogs): Harmful if eaten - for further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Care notes
Pruning and caring for Thermopsis lanceolata
- Cultivation
- Prefers well-drained soil in full sun or partial shade. Avoid waterlogged conditions.
- Pruning
- Cut back after flowering to maintain shape and encourage fresh growth.
- Propagation
- Seed, division in spring or autumn
Frequently asked questions
How do I grow Thermopsis lanceolata?
Prefers well-drained soil in full sun or partial shade. Avoid waterlogged conditions.
Where is the best place to plant Thermopsis lanceolata?
Thermopsis lanceolata prefers full sun and partial shade.
What soil does Thermopsis lanceolata need?
Thermopsis lanceolata grows best in well-drained and fertile soil. Aim for soil that stays moist to well-drained.
How do I prune Thermopsis lanceolata?
Cut back after flowering to maintain shape and encourage fresh growth.
How big does Thermopsis lanceolata grow?
Thermopsis lanceolata reaches a height of 1 metres.
Is Thermopsis lanceolata hardy in the UK?
Thermopsis lanceolata has an RHS hardiness rating of H5, meaning it is hardy in most of the UK, tolerating -15 to -10°C.
How do I propagate Thermopsis lanceolata?
Seed, division in spring or autumn.
Is Thermopsis lanceolata toxic?
Harmful if eaten. Wear gloves and other protective equipment when handling Pets (dogs): Harmful if eaten - for further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants.
