New tool will help gardeners move away from thirsty English classics to drought-resistant plants

Garden Climate Assessment Tool will allow users to predict a plant’s response to the projected climate in a given location

“In the 20th century, we could pretty much grow the same things with confidence, we could learn from previous generations,” said Prof Sam Brockington, a curator at Cambridge University Botanic Garden.

“But now we’re moving into climate scenarios that we just don’t have the traditions to understand fully.”

As gardeners around the UK are forced to adapt their growing habits to a rapidly changing climate, a coalition of leading UK horticultural organisations is developing an online tool that will help users predict which plants would survive in future conditions.

The Garden Climate Assessment Tool (GCAT), developed by the Future National Gardens Group (FNGG), will be a free risk-assessment tool that evaluates how a plant could tolerate the projected climate of a user’s chosen location.

Gardeners will be able to feed in a list of plants into the tool, which will take into account a number of factors including annual average temperature, natural distribution, winter cold and climate dryness.

The FNGG comprises horticultural, heritage and landscape organisations including the Royal Horticultural Society (RHS), the National Trust, English Heritage and the Royal Botanic Gardens.

On Monday, professional gardeners were invited to trial and provide feedback on the tool. A timeline for its release is uncertain, but the RHS’s director of science, Alistair Griffiths, said the long-term hope was that it would be made accessible to the wider gardening public.

It was created partly to spur the creation of climate-resilient gardens in the UK, and to inform gardeners’ decisions about what they plant in the future, aiming to help them anticipate the effects of the climate crisis on their plants rather than reacting to them.

Brockington said the new tool would identify plants in the UK that are struggling, so gardeners would be able to gradually remove them from collections.

The GCAT was based on Botanic Gardens Conservation International’s climate assessment tool, which was launched in Australia in 2022, focusing solely on trees. The UK coalition sought to move the model forward by expanding it to cover plants. There are up to 80,650 plant types and data from 289 UK gardens currently in the system, with plans for it to be continually updated to help strengthen predictions.

UK gardeners are increasingly having to rethink what they plant – drought is still declared in most of England, while rolling heatwaves scorched gardens and parks during the summer.

Laura Carey, who co-owns Carey Garden Design Studio with her husband, Joe, said: “One of the big questions for designers at the moment are what trees are going to be able to cope with our changing weather … Things like silver birch, I would be really wary of planting that in a garden, unless I knew that it was a fairly moist environment for it, because we’ve just seen them suffer so much over the past two very hot summers.”