The Agius Evolution Garden: a Journey Through Time

Posted by

Ali Barwani

6 June 2025

On 5 June 2025

The Agius Evolution Garden: a Journey Through Time

I find it astonishing that in 1998 I was working full time, and after work, in the evening, I would travel into Bloomsbury, to Birkbeck College to study for a degree. From where did I get this energy? I certainly couldn’t do it now! Part of the compulsion must have been the exciting botany lectures given by Dr Martin Ingrouille. We were being taught about plant evolution at a time when DNA sequencing was beginning to yield results leading to a more detailed understanding of the evolutionary history of plants. One of our field trips was to the Jodrell Laboratory, Kew Gardens to visit Professor Mark Chase and hear about his research into plant genetics.

Today I find myself back in a quiet corner of the Royal Botanic Gardens Kew, with the Jodrell Laboratory behind me. In front is the Agius Evolution Garden, a hidden jewel that tells the story of plant evolution using living specimens. For the past 170 years, this plot has hosted a succession of scientific gardens demonstrating contemporary understanding of plant classification. Its most recent incarnation, the Agius Evolution Garden, opened in the summer of 2019. This flowing garden is unlike the ordered rectangular beds I remember seeing all those years ago. Designed by Richard Wilford, with interpretation by Sharon Willoughby, the new garden displays our modern understanding of plant evolution over the last 400 million years through the discoveries of modern plant DNA analysis.

Historically, plant classification was based on grouping species into genera and families based on their morphology: that is physical characteristics like leaf shape and flower structure. However, recent discoveries in plant genetics have revolutionized taxonomy (the science of understanding and organising the diversity of life) allowing scientists to reveal hidden links between species. These revelations have reshaped the way botanists understand the evolutionary relationships of plants.

It is easy to stroll through this relatively small garden enjoying its beauty without being aware of the significance of its layout. However, the garden is much more rewarding if you take time to understand the science underpinning the design. A groundbreaking scientific paper analysing the DNA of 500 flowering plants was published in 1998 by Kew’s Professor Mark Chase and forty-one co-authors. The family tree resulting from this study brought many unexpected relationships to light. For example, who would have guessed that plane trees and lotus flowers are closely related?

This initial study has subsequently been added to by researchers around the world. The most recent version of the study, Angiosperm Phylogeny Group (APG) IV was published in 2016. The layout of the Agius Evolution Garden is inspired by this new classification. The space is divided into eight areas, or garden rooms, each representing different branches on the Tree of Life. Within each room, closely related plant families are grouped together, tracing their lineage back to a common ancestor, just like a family tree.

The Agius Evolution Garden has three goals. First and foremost, it aims to show the latest classification of land plants based on DNA analysis. Secondly, it seeks to enhance the beauty of the area for visitors while maintaining its scientific integrity. Finally, the layout is designed to make it easy for visitors to discover the exciting story of plant evolution for themselves. To this end, you will find that as you progress through the garden you will encounter helpful information panels explaining the significance of the surrounding plants, along with other intriguing plant science stories to add depth to your experience.

Each garden room represents a branch on the Tree of Life, delineated by clipped yew hedges for clear separation. From non-flowering plants like ferns and conifers to flowering plants such as irises, roses, and mints, the garden offers a comprehensive overview of plant diversity. The plants in the garden all do well growing outside at Kew, including hardy herbaceous perennials, annuals and some shrubs and trees. While it does not include all plant families, the Evolution Garden boasts over 700 different plant taxa.

The garden is bisected by a main path, covered by the Rose Pergola built in 1959 to celebrate the 200^th anniversary of Kew Gardens. My top tip is to walk to the end of the path, by Kew’s Kitchen garden, and start your journey back from here. This way you begin with the non-flowering plants, which then leads on to seven flowering plant rooms (representing the clades Magnoliids, Monocots, and Eudicots). Each garden room is curated to highlight the evolutionary relationships between the plants it contains and takes you onto the next evolutionary branch on the Tree of Life. With a layout designed to promote understanding of plant evolution, the Agius Evolution Garden is not only a feast for the eyes but also a valuable educational resource for visitors of all ages.

In conclusion, the Agius Evolution Garden invites its visitors to embark on a personal journey through plant evolution via a living tapestry of beautiful plants. By deciphering ancient relationships between plant species, this garden provides us with a deeper understanding of the living world, making it a must-visit destination for garden lovers and science enthusiasts alike. So why not visit Kew Gardens and explore the Agius Evolution Garden and unlock the secrets of plant evolution for yourself?