This study was undertaken to assess the effect of splitting of planting materials of taro (Colocasia esculenta) and tannia (Xanthosoma sagittifolium), and treatment with two commonly available growth hormones on plant establishment and yield. Conventional planting pieces of taro and tannia (called ‘huli’ made up of apical corm portions with attached petiole bases) were split longitudinally into halves or quarters and planted out in the field or treated with coconut milk (liquid endosperm) before being planted (in the case of taro). The field experiments for tannia were supported by greenhouse observations of split huli treated with coconut milk, or with acetylene generated from calcium carbide. In all cases, the split huli established more slowly in the field, produced a lower leaf area per stand, and produced lower yields than the intact huli. In both the field and in the greenhouse, the coconut milk treatment had a depressing effect on root growth and bud expansion. However, acetylene treatment promoted bud expansion in split tannia huli, and encouraged significant root development.