Also known as the yam bean, jicama ( Pachyrhizus erosus), a Mexican legume, is grown for its juicy, sweet tubers that are similar in texture and flavour to apples. Although it has high starch content, it’s low in calories and has a low glycemic index so is useful for diabetics and for weight control. Jicama fibre contains oligofructose inulin which enhances calcium absorption, so promotes bone density for protection against osteoporosis. Inulin also plays a prebiotic role, promoting good gut bacteria for healthy digestion and balanced immunity. All above-ground parts of jicama (especially the seeds and the bean-like pods) contain poisonous rotenone (the active ingredient in derris dust) but tubers are 100 per cent rotenone free. Subtropical jicama grows well in warmer areas of New Zealand. Treat seeds and plants like runner beans. Feed regularly.