Gardening Articles by Russell Fransham

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Bauhinia 'galpinii'
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Bauhinia 'variegata'
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Bauhinia 'blakeana'
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Bauhinia 'Bali'
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Bauhinia 'Monandra'
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Bauhinia 'purpurea'
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Bauhinia 'purpurea red form'
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Bauhinia

The genus Bauhinia, named after the sixteenth century French botanist brothers Bauhin, consists of about 250 species world-wide, of subtropical trees, shrubs and  scrambling vines characterised by twin-lobed leaves shaped like a butterfly’s wings and somewhat orchid-like perfumed flowers. Many of them are fairly hardy in northern NZ. The most popular species here are also some of the most florally impressive:

  1. Bauhinia purpurea, from Southern Asia is a hardy small tree to 5m with terminal clusters of 10cm purplish pink to pale pink flowers through Autumn. The petals are narrow and do not overlap. Initially lanky, it becomes bushy with age. Severe cutting back will induce bushy growth earlier and therefore more flowers.
  2. B. variegata from India is similar to B. purpurea but flowers through the Spring with white, pink, reddish or mauve-pink flowers with wider, overlapping petals than B. purpurea.  In a dry year the leaves drop revealing the massed flowers but more often in NZ the Winter and Spring are wet and the leaves remain on the tree obscuring and diminishing the flower display.
    In cultivation many Bauhinias sold as B. purpurea are probably hybrids between these two species and exhibit a wide colour variation from white (B. variegata candida) through every shade of pink to purplish red.
  3. B. blakeana is almost certainly a hybrid between B. purpurea and B. variegata with larger (12cm), darker flowers than either parent. The spectacular terminal panicles of flowers are lightly perfumed and in the tropics this one flowers almost continuously, although here it flowers from July till December. It is the national symbol of HongKong and is a popular street tree throughout the tropics. Being a sterile hybrid it can only be grown from cuttings which need to be of quite large diameter, at least 12mm and preferably over 15mm. Still fairly rare in NZ, this hardy hybrid grows fast and is a lush, handsome specimen to about 6m.
  4. B. galpinii is a South African native with bright orange flower clusters throughout Autumn along the tops of the arching horizontal branches, above the foliage. It is a handsome sprawling layered shrub in full sun but in the shade will scramble through other trees to reach the light. In NZ it is deciduous and hardy to light frost but in the tropics is virtually evergreen. Regular pruning back during Winter dormancy will keep this plant shapely and free-flowering.
  5. B. acuminata is a small shrubby plant to about 1.5m with beautiful white 5cm flowers, but it is more tropical (Thailand) and needs more careful treatment to thrive here.
  6. B. monandra is a beautiful tree species of 3 to 4m from tropical America with pale pink petals speckled with burgundy and one bright yellow and red petal. I have not seen this in NZ but it seems as hardy as B. purpurea in Australia.

These six species are among the hardiest in cultivation in my experience. Although many other shrubby and vining species will grow here, their flower displays tend to be either more ephemeral or simply less visually impressive.

Good drainage, full sun and some shelter from wind and hard frost will suit most Bauhinias. Most of them grow very vigorously and flower within a couple of years of planting. Apart from B. blakeana, they are generally grown from seed although variability is high among the hybridised types.

(Text and photography copyright Russell Fransham 2005)