|Sophora mircophylla subsp. var.||Kowhai|
S. microphylla or Kowhai is a semi-deciduous, moderately fast growing tree native to all parts of New Zealand. Unlike its cousin S. tetraptera, it has smaller leaflets of usually less than 10mm long, smaller flowers and tangled juvenile growth.
During spring, massed displays of tubular, yellow flowers of around 40mm appear. These are a favourite of both flower lovers and New Zealand native birds, who will rip the flower apart in order to get the nectar, rather than going through the mouth of the flower.
S. microphylla is best planted in a sunny or semi shaded position with moist, free draining soil. It is commonly seen growing along rivers and streams throughout all of New Zealand. It grows from around sea level up to 500m. Sometimes entire hillsides will be covered in the tree, producing a beautiful golden yellow display during the spring.
The seeds need to be treated specially to make them grow. In nature the hard outer shell of the Kowhai seed erodes away as it tumbles down streams, so the shell needs to be damaged somehow to allow water to soak into it. To allow this, one can take small nicks out of the shell using a pair of nail clippers or some similar instrument. After the chitting, the seed needs to be placed in a container of water to soak for a night.
The seeds are best planted in a coarse mix to allow for good drainage, this prevents rotting or fungal infections.
The germination period is 14-21 days.
The Kowhai can be grown from cuttings during autumn and early winter. They will take about 60-100 days to root and can be planted out in spring.
Pests and diseases
The Kowhai caterpillar is a bright-green and black caterpillar that strips the leaves of the kowhai. The treatment for such a problem is the use of an insecticide such as Orthene (NZ), Mavrik (NZ), Shield (NZ) or Super Shield (NZ).
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- ↑ Yate's 'Garden Problem Solver', HarperCollins, New Zealand, 2001
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963