Ginger is the underground root of a perennial plant, which is used as a spice, a preserve and has medicinal properties. The crop requires moist tropical conditions; the largest producers are China, India, Indonesia and Nepal. The rhizome is dug up when the 1 m tall leaves and stems of the plant wither. The product is used fresh, dried or preserved in syrup.

Hibiscus grows in many tropical and sub-tropical countries and is one of the highest volume speciality botanical products in international commerce. The herbaceous plants produce flowers which are labour intensively harvested for use in a range of products. There are many local and regional markets for hot and cold herbal beverages, jellies and confectionaries.

Turmeric is a rhizome of a perennial herbaceous plant native to South Asia which requires a tropical climate. Southern India is the world’s largest producer. It can be used fresh or dried and ground to a fine powder. It imparts a distinctive flavour but it is also used to provide food with a deep, orange colour. It is an important ingredient in the curry dishes and cuisine of South Asia.

Vanilla is a major natural flavour widely used in many products including foods, beverages, pharmaceuticals, cosmetics and tobacco. Vanilla seed pods are cultivated in many areas of the world but the main producing countries are China, the Comoros, Indonesia, Madagascar and Mexico, where the crop originated. Cultivation is highly labour intensive and the vanilla vines have very exacting requirements; warm, humid conditions, appropriate shade with soils rich in organic matter but with adequate drainage.