Kōwhai can be grown from seed or tip cuttings in spring and autumn. The dark or bright yellow seeds germinate best after chitting and being soaked in water for several hours. They can also benefit from a several minute submersion in boiling water to soften the hard shell and then being kept in the same water, taken off boil, for several hours to soak up the water. Young kōwhai are quite frost tender, so cuttings or seedlings should be planted in their second year when they are 30 cm or higher.