A rampant, large-leaved evergreen climber hung with pendulous clusters of pale blue to mauve trumpet flowers. Spectacular over big pergolas in the tropics, but a serious environmental weed in warm regions.
At a glance
- Plant type: Climber
- Mature size: 8 m H × 6 m W
- Aspect: full sun and part shade or morning sun
- Water: regular, moderate watering
- Frost: tender
- Maintenance: high maintenance
- Origin: Exotic
About Blue Trumpet Vine
Botanically, Thunbergia grandiflora is a fast-growing climber in the Acanthaceae family. It reaches around 8 m tall and 6 m wide at maturity, with evergreen foliage. Blue and purple flowers appear for much of the year.
Where to grow Blue Trumpet Vine
Blue Trumpet Vine suits tropical and subtropical climates and grows best in full sun and part shade or morning sun. It is frost tender, so protect it from hard frosts or grow it in a sheltered spot or pot.
Soil & planting
Blue Trumpet Vine does best in loamy and free-draining soil. Dig in plenty of compost before planting, water in well, and mulch to keep roots cool. For a screen, space plants about 3.6 m apart.
Watering & feeding
Blue Trumpet Vine does best with regular, moderate watering. A light spring feed is usually enough to maintain steady growth. For the first year, favour occasional deep watering over frequent shallow drinks so roots move into the surrounding soil.
Pruning & care
Prune Blue Trumpet Vine after flowering to keep it compact and encourage the next flush of blooms. It clips well, so trim two or three times a year for a formal finish. Expect a high maintenance care workload once it is established.
Using Blue Trumpet Vine in the garden
Blue Trumpet Vine earns its place for a shade tree, a feature or specimen planting and a fast screen or informal hedge.
Companion planting & design
For easier irrigation and care, group Blue Trumpet Vine with species that also favour regular, moderate watering and tropical climate. Leave enough room for the mature spread so neighbouring plants are not crowded out.
Good to know
It is thornless and easy to handle. Be aware it can self-seed or spread into bushland in some regions — check it is not a declared weed in your area before planting.
Buying Blue Trumpet Vine
Plant Sale lists Blue Trumpet Vine as potted plants and advanced specimens. Catalogue forms are planning guidance until the Plant Sale team confirms live availability.
