Commonly known as ‘Oxypetalum’
This is another tender evergreen sub-shrub from Brazil and Uruguay which is grown for its spectacular sky-blue flowers.
However beautiful the flowers this is a plant for the greenhouse or conservatory. It can be grown outside for the summer in pots but is unlikely to survive the winter outside.
T. caerulea has an erect and upright habit and needs support to grow well. Initially canes will suffice but a small wire trellis support may be best. The plant grows only to 2 or 3ft and looks as though it wants to be a climber but is not really despite its twining habit and downy/hairy stems. Its erect heart shaped leaves are attractive in their own right.
The flowers appear in July and carry on to September. They are in groups of three or four and are about an inch long. Slightly pink in bud they open flat to light blue and fade off to purple. The seeds are long, pointed, and erect on the plant. Green at first, they turn brown and split to reveal seeds with a downy dandelion-like top to enable them to blow away on the wind.
The seed need bottom heat to germinate in the spring but are not difficult. Cuttings need to be taken from soft new growth early in the summer and rooted on bottom heat.
This is a popular plant often treated as an annual in municipal plantings. Anything with blue flowers is popular and this odd plant is no exception.
