About

Indigofera gerardiana is a deciduous legume valued for its upright racemes of purple, pea-like flowers produced in summer. It forms pinnate leaves with numerous grey-green oval leaflets and typically reaches around 2–3 m in height and spread. Flowering in the UK runs from June to September. Plants can die back in colder sites but will regrow from the base the following season.

Wikipedia contributors, CC BY-SA 4.0 — Indigofera heterantha

About the genus

Indigofera is a large genus of over 750 species of flowering plants belonging to the pea family Fabaceae. They are widely distributed throughout the tropical and subtropical regions of the world.

Wikipedia contributors, "Indigofera", CC BY-SA 4.0 — Indigofera

In the garden

Indigofera gerardiana (Himalayan Indigo) originates from the north‑west Himalayas and belongs to the same genus historically used for indigo dye. In cultivation it presents as a multi-stemmed, flowering shrub with pinnate grey-green leaves and summer racemes of purple, pea-shaped flowers that appear from June to September. The species has been recognised by the Royal Horticultural Society with an Award of Garden Merit. Sit plants in a sunny, sheltered spot with good drainage; they perform best where they receive strong light through the day. Indigofera gerardiana tolerates periods of dryness once established and will withstand temperatures down to about −15 °C, placing it in the H5 (hardy) category for UK gardens. In colder microclimates the above-ground growth may be killed back to the ground over winter, with fresh shoots emerging the next spring. Use Himalayan indigo towards the middle or rear of a sunny mixed border, on a warm gravel bed or as a specimen where its summer racemes can be seen. Lightly prune to shape after flowering; in areas where it has died back, cut cleanly to ground level in late winter to encourage vigorous basal regrowth the following season.

More in the Indigofera genus

• 
  Indigofera
• 
  Indigofera articulata
• 
  Indigofera cassioides
• 
  Indigofera decorasummer wisteria
• 
  Indigofera frutescens
• 
  Indigofera leucotricha
• 
  Indigofera szechuensis
• Indigofera anilanil