Columnea : Greenhouse Plants
W – warm, minimum of 13°C (55°F)
These make splendid hanging basket plants. Despite liking warm temperatures they can withstand and even flower better after cooler winter conditions. Most grow very long trailing stems. If plants become bare of leaves at the top they can be cut hard back to within a few centimetres of the base usually towards the end of the summer or after flowering. This will give them time to grow back again before flowering. In their native rain forests they would be semi, growing in niches in the trees. It is not hard to imagine that they dislike wet stodgy composts so allow the in the basket to dry out slightly between waterings especially if being kept cool in winter. Never squirt them with water as they are all prone to water scorch on the leaves.
Most commonly grown is Columnea X banksii which produces stems up to 1.2 m (4 ft) long, very slightly hairy leaves and orange-red tubular flowers early in the year and usually again later. C. microphylla is attractive, especially C. m. ‘Tricolor’ as its small hairy leaves are prettily variegated and look especially nice with the orange-red flowers. My favourite is C. gloriosa ‘Purpurea’ from Costa Rica. The flame-coloured large flowers look super in late winter against the hairy purple foliage. There are several hybrids, the most unusual of which is C. ‘Alpha’ with yellow flowers. Cuttings 8 cm (3 in) long root well and are best pinched out to encourage a small branched plant. Oncehave filled small pots they can be planted six to a basket in peat-based and will soon begin to trail over the edge. Seed should be surface sown in a light place at 21-24°C (70-75°F).