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. Plant into well-prepared ground, firm the soil around the roots and water deeply to settle it in. For a screen, space plants about 3.6 m apart.
Watering & feeding
Blue Trumpet Vine is regular, moderate watering. A feed in spring with a balanced fertiliser keeps growth strong. In its first year, water deeply once or twice a week to settle the roots in, then taper off as it establishes.
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. Overall it is high maintenance.
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 a cohesive, low-care bed, pair Blue Trumpet Vine with other plants that enjoy the same regular, moderate watering and tropical climate. Repeat it through a border to tie the planting together and give a sense of rhythm.
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. Stock isn't live yet — register your interest using the panel above and we'll email you the moment we have it ready.