Blue trumpet vine

Thunbergia grandiflora | Also known as: Bengal clock vine, Bengal trumpet, Blue skyflower, Blue-sky flower vine | Rating: 0 votes | Print / Pdf

A vigorous twining evergreen shrub, thunbergia grandiflora is a highly effective option when it comes to enlivening bare surfaces with rich foliage. A favourite for wall-sides, it produces dense, dark green foliage comprising broad, heart-shaped and coarsely serrated leaves, which hang loosely from climbing vines on short stems. In summer, its delicately attractive, pale blue trumpet-shaped blossoms emerge, featuring five ragged-looking petals with dark yellow throats. Commonly known as the blue trumpet vine, it is best to grow under glass in loam-based compost and bright filtered light. Water freely while growing but rarely in winter. Outdoors, plant in moist but well-drained loamy soil in sheltered locations. Pruning after flowering is advised

Rate it:
Known dangers?
  • no
Height [m]
  • 5 - 10
Spread [m]
  • 5
Dominant flower colour
  • Varies
Flower Fragrance
  • No, neutral please
Flowering seasons
  • Early summer
  • Mid summer
  • Late summer
Foliage in spring
  • Green
Foliage in summer
  • Green
Foliage in Autumn
  • Green
Foliage in winter
  • Green
  • Yes, let it smell
Propagation methods
  • semi-ripe cuttings
  • Greenwood cuttings
  • seed
  • layering
Growth habit
  • Climbing
  • Twining
  • Tapering
  • Acidic
  • Neutral
  • Alkaline
Hardiness zone
  • Z14-15
Heat zone
  • H12-10
Winter temperatures [°C]
  • 0
Heat days
  • 150 - 210
  • well-drained
  • well-drained but frequently watered
Soil type
  • loams
Sun requirements
  • Full sun
  • Sheltered
Standard category
  • Flowers & bulbs
  • Perennials
Grown for
  • Attractive Flowers
Creative category
  • Fast growing
  • For Beginners
  • Author's choice
Garden type
  • Cottage garden
  • Containers
Garden spaces
  • Walls, trellises and pergolas
  • Borders
Gardening expertise
  • beginner
Time to reach full size
  • Less than one year