Overview. Turmeric is a spice that comes from a tropical herbaceous plant. It can be grown only in tropical conditions. Most gardeners who want the spice will grow it indoors or in a heated greenhouse. The spice is produced in the rhizome of the plant that resembles that of the ginger rhizome.Turmeric is started with fresh roots, which can be found in some health food stores, nurseries or online.ost gardeners who want the spice will grow it indoors or in a heated greenhouse. The spice is produced in the rhizome of the plant that resembles that of the ginger rhizome. Turmeric is started with fresh roots, which can be found in some health food stores, nurseries or online.