Explore Kew’s new Carbon Garden: Nature that fights climate change

The Carbon Garden is one of the most ambitious projects Kew Gardens has undertaken in recent years. It displays innovative design combined with beautifully arranged plants and flowers, divided into distinct sections. Informative panels throughout the garden provide more information on carbon, ecosystems and the carbon cycle.

What is the mission of the Carbon Garden?

I spoke with Lara Michael, Senior Project Manager at RGB Kew, about the ideation of the project, the challenges faced along the way and its wider meaning for us.

She shared that the idea for it started in 2021, but the biggest challenge was to finish it within the six-month window leading up to the opening. This required extensive collaboration and communication across multiple teams.

The garden is unique in that it celebrates the carbon cycle and addresses climate change by testing climate-resilient plants and water conservation methods. It features an irrigation system linked to soil probes, ensuring plants are only watered when the soil needs it. The system is also connected to a weather station to further optimise water conservation.

The plantings will evolve over time, but the focus is on climate resilient species, especially trees and different types of grasses that capture carbon in the soil. The garden also serves as a pilot study, with the anticipation that in 2050 the UK climate will be more like the Mediterranean.

What sections can you find at the Carbon Garden?

The Carbon Garden is divided into themed zones, each highlighting what carbon is, where it can be found and what we can do to reduce emissions through carefully planned planting schemes that take carbon storage, water retention, drought and heat resilience as well as biodiversity into consideration.

One section includes herbaceous perennials which are used to showcase the rise in global temperatures through colour schemes, blue and purple for the colder zones and reds and orange for the warmer zones.

Another area, the Dry Garden, evokes a Mediterranean landscape and includes plants and flowers that are more drought and heat resistant. The soil that has been used is a mix of sand and repurposed crushed concrete, which is great for drainage due to the porosity yet also helps retain moisture.

You’ll also find a wildflower meadow and native hedgerows, both of which boost biodiversity and contain insect hotels. As well as grasslands which are often underestimated but offer a great contribution as their deep roots help store carbon in the soil.

The final section is the Rain Garden. Richard, Head of Garden Design at RBG Kew explains how this garden demonstrates ways to manage water flow, which in turn reduces flooding and how water-tolerant plants help to maintain soil stability.

What is carbon and why should we care?

Carbon is the building block of life. All living organisms on planet Earth are carbon-based making it essential to our survival and the survival of the planet in general. Carbon is found in everything from trees, humans, coal and the atmosphere. As with anything, too much of something or too little can have a negative impact. When burning fossil fuels and other materials, we produce carbon emissions which release CO2 into the atmosphere which drives climate change, but there are ways to capture carbon and reduce emissions and thus slow down climate change through plants and fungi.

What is the meaning behind the mushroom centerpiece?

At the heart of the garden stands a gigantic mushroom sculpture, created by Maltese-British architect and designer, Jonathan Mizzi.

Jonathan recalls a conversation with Richard about the Tenor Oak Tree, which was tilted over with its roots exposed due to soil compaction. It was saved from being cut down and revived after a storm. He continues that they discussed creating something that celebrates the symbiotic relationship between plants and fungi, using low carbon materials such as wood, linen and other natural elements for the centerpiece to embody humanity living in harmony with nature.

Which role do fungi play and how important is biodiversity?

I spoke with Laura M Suz, Senior Research Leader in Mycology, and Amanda Cooper, PDRA in Natural Capital Modelling, about the role fungi play in the ecosystem, how they help with the climate crisis and the importance of biodiversity.

Laura: Fungi have many different roles in the ecosystem and are dealing both in the carbon cycle as decomposers of organic matter (releasing carbon dioxide into the atmosphere while recycling nutrients back into the ecosystem) and forming relationships with plants storing carbon in soil and slowing down its release.

Some fungi are part of a group called mycorrhizal fungi which form symbiotic relationships with the roots of plants. Mycorrhizal fungi get nutrients and water from the soil that transfer to the roots of the plant and in exchange the plants give carbohydrates and fats to the fungi which means they get 5 to 30% of the carbon from the photosynthesis and so the plants transform carbon dioxide into sugars that are then transferred to the fungi. Studies have shown that this mycelium in the soil of those mycorrhizal fungi is a huge carbon pool as around 36% of the carbon dioxide from emissions gets translocated per year through the plants into the mycelium. There is more carbon in the soil then in the atmosphere and plants together.

Amanda: To increase biodiversity, it is important to understand how a healthy ecosystem functions. Rather than prioritising single products like just planting one crop in agriculture or forestry one needs to consider a multitude of plants and shrubs and trees that all support each other like throwing needed shade onto each other and provide a balance between the diverse parts of an ecosystem. That includes human needs with those of nature. This project recognises the need for a diverse network of species to support it, adapting to climate change by selecting resilient plants.

How do new generations become more aware of carbon emissions and get inspired by this project?

Amanda, who focuses on human stewardship and ecosystems, tells me that scientists regularly visit schools to share their work, and Kew is offering regular school visits.

The installation allows visitors to observe plants and learn about the role they play in the carbon cycle, which they can share with their families and friends. Also, when children are interested and read more about the project on the panels throughout the garden they tend to draw in adults that may be less curious.

Is the new Carbon Garden at Kew Gardens worth visiting?

From immersive installations to informative panels and eye-catching designs like the mushroom centerpiece, if you’re looking for an experience that’s both visually impressive and thought-provoking, the Carbon Garden is well worth a visit. Whether you’re a plant enthusiast, a family looking for an educational day out, or simply curious about climate solutions, the garden offers something for everyone.

Book your Kew Garden tickets now which include access to the Carbon Garden.