Famous tea house supports researcher in examining 200 year-old leaves

A joint initiative bringing together a Sri Lankan researcher and the world-famous UK-based tea company Ahmad Tea, alongside the Royal Botanic Gardens Kew, the Tea Research Institute of Sri Lanka and the University of Peradeniya, is investigating why certain tea cultivars cope better than others under water scarcity. Leaves collected from Sri Lanka’s hills 200 years ago may now hold clues to safeguarding the future of tea.

Sri Lanka produces up to 300 million tonnes of tea annually — enough for an estimated 150 trillion cups — and the industry supports more than 2.5 million people. Tea saplings require about two years to move from nursery beds into plantations and can live for up to a century. Yet they are highly vulnerable: increasingly frequent droughts and heatwaves can wipe out young plants or devastate entire estates, placing countless livelihoods at risk.

The research aims to identify or develop tea cultivars capable of thriving with less water while preserving quality, as highlighted in a recent documentary by Reuters, ensuring tea production remains viable despite harsher climate conditions.

Tea was introduced to Sri Lanka — then known as Ceylon — during British colonial rule and has since grown into one of the country’s leading exports.

Remarkably, specimens gathered by botanists 200 years ago are still preserved in the UK at Kew.

Caspar Chater of Kew described the institution’s collection of seven million dried plant samples as a “time machine” for researchers.

“They provide us with information about past climates, past diseases that affected tea and how tea diversity has changed over time,” he said, as cited by Newswise. 

Thamali Kariyawasam relocated from Sri Lanka to the University of Bristol to explore ways of protecting tea crops from the effects of climate change.

Older tea cultivars may prove more resilient than modern selectively bred varieties. At the same time, examining how contemporary tea leaves have evolved — including their response to rising atmospheric carbon dioxide levels — could offer new insights into breeding hardier plants for the future.

“Thamali’s research is a great example of how we are leveraging plant diversity to adapt to climate change.

Zahra Afshar of Ahmad Tea, who studied at the University of Bristol before joining the family firm and now serves as head of legal affairs, said there has been “astonishingly little” research into how climate change is affecting tea.

“Climate change is already affecting the cost of production and yield in tea-growing regions, putting suppliers under pressure and causing instability,” she said. Ahmad Tea plans to share the findings with the wider industry to help others prepare for the challenges ahead.

“There’s not much public visibility of the issue, and very low tea prices means that suppliers often don’t have the funds to respond to this existential crisis, for instance by investing in regenerative farming.

Kariyawasam’s work could help farmers adapt to an uncertain climate future and sustain yields, protecting the livelihoods of the many workers employed as tea pickers.

Thamali added: “It’s really important that we discover plants that can stand these dry periods. And identify which plants could bear a drought well and still produce a good yield.

By Nazrin Sadigova