A promising new climate tool for gardeners, and the part only you can add

The Garden Climate Assessment Tool is a welcome step, and it comes from people who know plants. The Future National Gardens Group includes the RHS, the National Trust, English Heritage and the Royal Botanic Gardens. The tool will take a list of plants and assess how each is likely to cope with the projected climate at a chosen location, using annual average temperature, natural distribution, winter cold and climate dryness.

The Guardian reported on 3 November 2026 that professional gardeners had been invited to trial it, with no release date set. The data covers up to 80,650 plant types and 289 UK gardens.

It should be genuinely useful. One thing it doesn’t cover yet is soil, which decides a great deal in a vegetable bed.

What the tool can and cannot know

A climate tool works at the scale of a location. It can tell you that a garden in Surrey is projected to have hotter, drier summers, and that a plant from a wet, cool climate may struggle there.

It cannot tell you that your bed is on chalk, that the subsoil is clay, that the bed slopes south and dries out in March, or that the corner by the wall stays wet until May. Those are the things that decide whether a plant survives in your garden.

The RHS’s director of science, Alistair Griffiths, told the Guardian that soil type is not currently a variable. In the same article, Kim Shrosbree of the Epsom Garden Society, who gardens on chalk, said that many plants suited to her area’s climate wouldn’t grow in her soil.

That holds for most gardens. Chalk drains fast and dries out; clay holds water and can waterlog; sand is hungry and dries quickly; loam is the easy middle. pH changes what can take up nutrients. None of that shows up in a location-based climate score.

Why it matters more for vegetables

Ornamental planting can often be moved, replaced or given extra water. A vegetable bed is a production system. You are asking a plant to crop within a season, not just survive.

A drought-tolerant crop on thin chalk may still fail, because the water it needs disappears before its roots can follow. A thirsty crop on heavy clay may sit in water and rot. The same tomato variety can be fine in a raised bed with compost and poor in a cold clay border ten metres away.

The developers may add soil later. Until then, it works best as a climate filter used alongside what you know about your own beds.

What to do this winter

Find out what your soil is. Dig a hole, take a handful, and squeeze it. Clay holds together and feels sticky. Sandy soil falls apart. Chalk is pale and stony. A jar test settles the particles into layers. A simple pH kit is cheap and tells you what will grow.

Add organic matter. Compost, leaf mould and well-rotted manure improve both sandy and clay soils, though in different ways: sand holds more water, clay drains better. Do it every year, not once.

Mulch. A 5 to 7.5 cm layer over wet soil cuts evaporation and keeps the surface cooler. It is the best drought insurance you can buy. How to mulch a vegetable bed has the depths.

Match crops to the bed. Put thirsty crops on the retentive soil and drought-tolerant crops on the free-draining soil. Drought-tolerant vegetables has the list.

Improve the wet spots. Raised beds, a rough surface and organic matter help clay drain. Do not dig clay when it is wet; you will make a worse mess.

Store water. A butt on the shed roof is more useful than a promise of rain. Water butts and ollas does the sums.

Use the tool when it arrives

When the Garden Climate Assessment Tool is released, use it for what it does well: screening a plant list against a future climate, and spotting the plants that are likely to struggle. Then check the result against your own soil, your frost dates and what you have seen grow.

That’s how any climate projection is best used: the projection is regional, and the garden is local.

For the wider picture, see growing vegetables in a changing climate.