A coalition of leading UK horticultural organizations is building a free online tool that forecasts whether plants can survive the climate projected for a gardener's own location, a bid to help growers plan for drought and heat before their gardens fail.
Called the Garden Climate Assessment Tool, the risk-assessment system is being developed by the Future National Gardens Group. Users enter a list of plants, and the tool weighs factors such as annual average temperature, each plant's natural distribution, winter cold and how dry the climate is.
The group brings together horticultural, heritage and landscape bodies including the Royal Horticultural Society, the National Trust, English Heritage and the Royal Botanic Gardens. Professional gardeners were invited on Monday to test the tool and offer feedback.
No release date has been set. Alistair Griffiths, the RHS director of science, said the long-term hope is to open it to the wider gardening public.
What powers the tool
The system currently holds up to 80,650 plant types and data from 289 UK gardens, and its developers plan to keep updating it to sharpen its predictions.
It builds on a climate assessment tool from Botanic Gardens Conservation International that launched in Australia in 2022 and covered only trees. The UK coalition expanded that model to include plants more broadly.
The aim is to let gardeners anticipate the effects of the climate crisis rather than react after the damage is done. Sam Brockington, a curator at Cambridge University Botanic Garden, said the tool would identify struggling plants so gardeners could phase them out of collections over time.
But now we’re moving into climate scenarios that we just don’t have the traditions to understand fully.
Sam Brockington, curator at Cambridge University Botanic Garden
Designers weigh in
The pressure is already visible. Drought remains declared across most of England, and rolling heatwaves scorched gardens and parks this summer.
Laura Carey, who co-owns Carey Garden Design Studio, said she would now be wary of planting silver birch outside fairly moist settings after watching the trees suffer through two very hot summers. She said the tool's attention to the changeability of the weather, not just rising temperatures, could support longer-term choices.
Clive Boase of the charity Climate Change Gardening said the tool could give gardeners in the east of England, the UK's driest region, the confidence to drop water-hungry staples such as lush lawns, hydrangeas and delphiniums, though he acknowledged such shifts are hard for people attached to a traditional look.
They have to be supported in making those changes.
Clive Boase, Climate Change Gardening
A gap on soil
Griffiths said soil type is not yet a variable. Kim Shrosbree, secretary of the Epsom Garden Society, said that matters because gardeners on chalk and clay face opposite conditions, estimating that about 70% of plants suggested for the Epsom area would likely not grow in her chalky ground.
Garden designer Juliet Sargeant called the location feature essential, arguing that generic planting advice no longer works and that results will increasingly depend on each individual garden.
