Chocolate on the menu at Gardeners' Question Time Summer Party


Visitors to the BBC Radio 4’s Gardeners' Question Time Summer Party at the Royal Botanic Garden Edinburgh (RBGE) on Saturday (9 July) will get the chance to learn about the threat of a global shortage of chocolate and research being undertaken to offset the crisis.

A study into the age of chocolate and its source is being undertaken by RBGE’s tropical botanist Dr James Richardson in association with counterparts in Colombia and the United States of America.

As the worldwide demand for chocolate increases by 2.5 per cent a year, research undertaken by Dr Richardson, the University of Rosario and the University of the Andes, in Colombia, the University of Miami and the United States Department of Agriculture (USDA) has demonstrated that Theobroma cacao, the species that is the source of chocolate, has been around for 10 million years and evolved as the Andes were being formed.

This is important because, as popularity soars, a key challenge associated with current growing practices is the lack of variety of cultivated material – hybrids and common cocoas often have low resistance to pests and blights. There is also the need to ensure the long-term sustainability of the industry by protecting plants from the risks posed by climate change.

As with many crops, the extent of genetic material utilised from native populations is limited. Therefore, information on genetic diversity and related species would be invaluable for improving the quality and quantities of material that could be produced to meet the increasing demand.

Dr Richardson, who is the lead author on the international study explained: “Cacao is remarkably old for a plant species and confirms that there has been adequate time for the evolution of a significant amount of genetic diversity within the species. We hope to highlight the importance of conserving biodiversity so that it can be used to augment and safeguard the agriculture sector. By understanding the diversification processes of chocolate and its relatives we can contribute to the development of the industry.’’

Dr Richardson will be based in the Plants and People Glasshouse during the Gardener’s Question Time event to talk to visitors about his research and how it can contribute towards  meeting the growing demand for chocolate. Visitors will see a specimen of the Theobroma cacao growing in the House.

Gardeners' Question Time Summer Party will be held from 10am to 5pm. Tickets cost £10.50 for adults and £5 for children (5 – 16 years), under 5’s free.


The Royal Botanic Garden Edinburgh is a charity (registration number SC007983)