The movement of people to the warm temperate or subtropical parts of the North Island has encouraged interest in Australian and South African plants, especially in trees and shrubs like acacias, banksias, waratahs, aucospermum, leucadendron, and proteas. Further south, particularly in Christchurch, bedding plants make a great display from September to April. Winter flowers comprise Iceland poppy, anemones, and Soleil d'Or narcissus; in sheltered places in both Islands, cinerarias, Primula malacoides, and polyanthus flower well in spring. In relatively frost-free areas dahlias can be left over winter in the ground, and autumn-flowering bulbs, such as nerines and amaryllis, are widely grown. The white arum lily, a traditional glasshouse plant in Europe, grows freely in damp soil in many places, especially around farm homesteads. Roses grow well everywhere and in a good season will flower from October until May, producing 5 ft or more of new growth a year. Lightly pruned hybrid tea roses, which may grow 8 ft or more in the milder areas, can be truly described as rose trees. This ample supply of flowers throughout the year has encouraged housewives to take up floral art, so much so that this is now an important domestic activity.