Bougainvillea: Greenhouse Plants
C – cool, minimum of 7°C (45°F) / W – warm, minimum of 13°C (55°F)
Although originating from South America, in particular Brazil, these plants have become common wherever the climate allows them to grow. Visitors to the Mediterranean will remember their vivid blooms in hedges and twining around the balconies of houses and hotels. The exotic papery flowers of Bougainvillea are in fact bracts. If you look closely you can see that there are true flowers inside. They make excellent greenhouse specimens and can either be trained up a wall or trellis or pot grown and trained up canes. Their versatility extends to temperature. By keeping them very much on the dry side they can be overwintered in a frost free house, in which case they drop all their leaves, become dormant and could be pruned back to within one bud of old wood in spring, at the same time as being gradually watered to encourage growth. An added boost at this time would be to move them to a warm but bright position in the house or warmer greenhouse to promote the development of new shoots. If a warm temperature can be provided it is possible to have earlier flowers by keeping the plants growing through winter. Pruning would then be a case of cutting back only unwanted shoots after flowering in late summer. Propagation is mostly by taking 8-cm (3-in) side shoots with a heel of older wood in spring or early summer. It is possible to use hardwood taken from the early prunings of dormant cool growing specimens.
The most commonly found species is Bougainvillea glabra which has mauve or pink bracts. B. g. ‘Variegata’ is very good for its creamy-white variegation. There are many hybrids with large showy bracts, the colour range including orange, rose, white and even pink and white. My favourite is B. ‘Miss Manila’, the bracts of which are a glorious warm orange to begin with but open to a very showy pink. It pays to watch out for early signs of aphid attack, which if left unchecked can lead to distorted bracts and shoots.