Calliandra is a popular plant in the U.S. but rarely grown in Great Britain. The leaves are made up of a large number of segments and the flowers are made up entirely of stamens. It blooms in winter and the ‘powder-puffs’ last for 6-8 weeks.
Calliandra inaequilatera has bright red flowers and dark green foliage. A better choice is the hardier Calliandra tweedii – the flowers are smaller and the leaves are feathery. Calliandra surinamensis has perfumed pink powder-puff and tiny, fine leaves. It’s hardy, compact rounded bush. Calliandra haematocephala has vivid pink, big powder-puff flowers from October to May. Native to Bolivia, this plant becomes a small tree with many-segmented, eight-inch leaves. Calliandra californica gets 6 ft. x 6 ft. in an open, vase-shaped shrub and red puffball flowers. Its dark green leaves are like tight miniature ferns, overshadowed by red spikey flowers.
Powder puffs are not especially difficult to grow indoors, but it can be tricky coaxing them to bloom. They prefer regular moisture, high humidity, bright light and high temperatures. In the absence of these conditions, they will not grow as vigorously and will likely not bloom at all. Calliandra needs light, warmth and moist air which means that it is more suited to the conservatory than the living room. The compost has to be moist at all times, but reduce watering in winter. Keep it pruned to 2-3 ft by trimming in spring. Repot also, if necessary, in early spring.
Calliandra can be relatively easily sprouted from stem cuttings. During the spring, when new growth emerges and the winter bloom has faded, take a cutting and pot it in seed-starting soil. Rooting hormone and bottom heat increase your chances of success. These are not especially fast-growing plants, so don’t expect a bloom that first year.