Kew Explorer Form


Great Broad Walk Borders

Originally created in the 1840s, the Broad Walk was designed to serve as an impressive formal promenade to the newly opened Palm House.

To bring back the atmosphere of an ornamental promenade to the Palm House and emphasise the perspective, these new borders run right along the edge of the path and a row of topiary yew trees (Taxus baccata) have been planted each side.  A new series of circles are now bisected by the path in the shape of a bean pod, inspired by the tropical vine Entada gigas – the largest seed pod in the legume family – also known as the sea bean or monkey ladder. 

We have planted 30,000 plants for a diversity of texture and colour with the greatest impact between June and September. There are bulbs for spring and some late flowers and seed heads for autumn interest.

A large number are cultivars, selected to give an extended flowering season and reliably bring colour to the scheme. The borders also include some wild plant species and plants from Kew's own collections that have been propagated to make the borders unique and distinct.

Border themes

The circles in the border design are themed to reflect the botanical and horticultural science at the heart of Kew’s mission. Some beds are based on a single plant family or group with others highlighting various characteristics of plants, and how they may have adapted to environmental conditions in the wild.

These star plants are examples of each theme:

  1. Hybrids and cultivars - Penstemon 'Schoenholzeri'
  2. Lamiaceae zone - Perovskia ''Blue Spire'
  3. Compositae zone - Heliopsis 'Summer Nights'
  4. Monocots zone - Dwarf red-hot poker
  5. Plant life cycles zone - Verbascum 'Spica'
  6. Pollination zone - Milky bellflower
  7. Seed dispersal zone - Geranium 'Rozanne'
  8. Shade tolerance zone - King's lily (Lilium regale)
IB Header Text: 

Why these plants matter

IB1 Title: 

Lamiaceae bed

IB1 Text: 

The Lamiaceae family is an important group of plants for Kew’s research. Kew scientists have used the diverse living and preserved collections to research the bioactivity of Salvia extracts and compounds underlying their medicinal use.

IB1 Image: 
Perovskia in the Lamiaceae bed
IB2 Title: 

Monocots zone

IB2 Text: 

Monocots are of great economic importance as a source of human and animal food. All cereals, palms, bamboos and sugar canes are monocots. Kew carries out research on a wide range of monocots, from the classification of orchids to the evolution and economic uses of grasses.

IB2 Image: 
Kniphofia cultivar in the Monocots bed
IB3 Title: 

Pollination zone

IB3 Text: 

Insect visits are crucial for many plants because they need help from pollinators to produce seeds. Kew scientists are working on developing a technology which could help commercialised bees become more efficient and ensure they do not take food from wild pollinators.

IB3 Image: 
Bumble bee pollinating salvia in Great Broad Walk Borders
About title: 
About the Borders
AE Header: 

Related events and courses

Attractions & Events References: 
Introduction to planting design
Plant identification skills
Spring photography masterclass
Info Blocks: 

Why these plants matter

Lamiaceae bed

The Lamiaceae family is an important group of plants for Kew’s research. Kew scientists use the diverse living and preserved collections to research the bioactivity of Salvia extracts and compounds underlying their medicinal use.

Perovskia in the Lamiaceae bed

Monocots zone

Monocots are of great economic importance as a source of human and animal food. All cereals, palms, bamboos and sugar canes are monocots. Kew carries out research on a wide range of monocots, from the classification of orchids to the evolution and economic uses of grasses.

Kniphofia cultivar in the Monocots bed

Pollination zone

Insects are crucial for many plants because they need help from pollinators to produce seeds. Kew scientists are working on developing a technology which could help commercialised bees become more efficient and ensure they do not take food from wild pollinators.

Bumble bee pollinating salvia in Great Broad Walk Borders

Plants and conflict landscapes – the Somme and beyond

Blog team: 
James Wearn & Andrew Budden

The Flora of the Somme Battlefield and its author, Arthur Hill (Image: RBG Kew).

Why the Somme?

This June, Kew’s First World War Centenary project team undertook an emotive quest to return to the Somme (an area of northern France where a series of WW1 battles took place). Our team, also including Sarah Veniard and Paul Little, was joined by David Richardson, Director of Horticulture at the Commonwealth War Graves Commission (CWGC).

Kew’s longstanding relationship with the Commission began ambitiously in 1916 and led to the characteristic planting regimes with which we are familiar today.

There were three elements to our collaborative undertaking:

  • Commemoration – a tribute to the 'Kewites' who found themselves on those perilous battlefields 100 years ago, especially those who never returned.
  • Assessment – of the ‘conflict landscape’ in the context of the regenerated flora and modern land use.
  • Consideration – of modern challenges to commemorative horticulture, using science to inform resource sustainability, plant tolerance to climate change and the development of management plans.

Discussing the planting with CWGC at Forceville Communal Cemetery (Image: Paul Little).

Our inspiration came from two unique and little-known accounts written immediately after the battles by former Kew Director, Sir Arthur Hill:

  • The Flora of the Somme Battlefield (1917), a poignant account of plant succession; and,
  • Our Soldiers’ Graves (1919), an overview of the initiation of formalised war cemeteries and horticulture therein.

In partnership with the CWGC, we retraced Arthur Hill’s steps as he travelled through the region shortly after the battles. As Botanical Advisor to the Graves Registration Commission, he observed and contemplated both the shocking destruction and the re-birth of flora from the scarred terrain.

A documented ‘flora’ of the Somme was not new – early works include Pauquy (1831) and De Vicq (1883) – but Hill’s work captured the rawness of recent turmoil and has since been duly hailed as a “very moving account” (e.g. Stott, 1970).

Innumerable explosions had thoroughly mixed topsoil with the underlying chalk on the Somme. From the in situ seed bank, the soil’s back-up store house of plant propagules, germinated an array of ‘weeds’ which was striking to behold; Hill (1917) described this as a “sheet of colour as far as the eye could see”. Moreover, the process of plant succession was restarted as the landscape began to regenerate, much like the nations that were at war. Ex-situ seed banking by botanic gardens similarly provides an ark-like facility in the form of off-site cold stores, which are vital long-term conservation resources.

The most famous and potent flower launched from dormancy was, and remains, that of the field poppy, Papaver rhoeas (Wearn, 2016a). This environment, however, encapsulates so much more. The ‘illusionary’ nature of the post-war landscape, reclaimed and refashioned, has been remarked upon by conflict archaeologists (e.g. Leonard, 2011). Similarly, the striking and sudden emergence of floral cover soon after the battles began to mask the deathly character of the scene, removing the physical immediacy of the memories associated with it.

A lone poppy emerges from a field of barley near Thiepval (Image: P. Little).

Changing landscapes

Driving along the country roads – once punctuated by ruined villages surrounded by bustling networks of trenches and shell holes, scarred and pock-marked as if the Earth itself was suffering some kind of chronic disease – at first glance all is now serene. Yet the (still deadly) ‘iron harvest’ turned over each year in the fields, the numerous timeless cemeteries and memorials dotting the horizon and the lasting craters such as Lochnagar, leave anyone passing through in no doubt that this has become a ‘sacred and mythological land’, still full of the dead and dominated by remembrance.

At a physical level the landscape has endured turmoil, yet is once again much like its former (pre-WWI) self. Many of the concentrated patches of woodland take similar forms as they did before July 1916, whether regrown or replanted, appearing as inoffensive now as they (deceptively) did then.

At an experiential level, the landscape engaged the emotions of those who fought there just as it does with those who visit today, through its outward scars, memorials, and the numerous narratives of events which took place there. The primary driver for memorials immediately after the war was personal and national mourning, but their form and simple messages etched upon them now leave a significant challenge to the Commission for communicating meaning to modern society.

In a similar way, climate change and sustainable land management have led to a renewed Kew-CWGC interaction to consider science-based horticultural practices going forwards.

Thistle Dump Cemetery with the notorious killing ground of High Wood behind (Image: J. Wearn).

The interplay between the brief but forceful militarisation of the Somme, its reversion largely to agriculture and chalk downland, and multiple sites of remembrance, has determined its current morphology and our perceptions of the landscape.

Imagine your pleasure in seeing the first flower after a long winter. Now imagine that ‘winter’ spanned years and that you observe a colourful bloom emerge from a morass of twisted scarecrow-like trees and mud. It is unsurprising that service personnel throughout the centuries have actively gathered and carefully pressed small floral symbols of hope, for themselves, for loved ones back home, and even for the advancement of science (e.g. Wearn, 2015).

Post-war landscapes have frequently taken on new characteristics; both morphologically and through the way they are perceived (Wearn, 2016b). Conflict landscapes often also develop a flora quite unlike the surrounding regions. Cultural and political divides in the form of demilitarised zones, such as that between North and South Korea, have become areas of conservation importance. Acknowledgment of this resulted in a special publication for the 12th Conference of the Parties to the Convention on Biological Diversity (DEPG, 2014). Similarly, Kew’s botanical research within conflict landscapes in Angola is finding that land mine fields (from the civil war of 1975–2002) can also become unintentional protective zones for biodiversity. The presence of mines set in motion a series of interactions among conflict, livelihoods, settlement, development and conservation. Post-conflict mine field clearance is allowing resettlement, grazing and infrastructural development, often with associated declines in natural biodiversity resulting from environmental degradation. Furthermore, drawn out conflicts can render regions scientifically undiscovered, such that entire landscapes of new plant species may be found (e.g. Mabberley, 2009).

Conservation and commemoration

Intriguingly, commemoration and nature conservation are not always easy bedfellows, necessitating careful consideration when balancing the needs of one along with the other (for example, saxicolous lichens and war graves, Wearn & Hudson, 2014).

Renowned botanist, Francis Rose first drew comparisons between the chalkland floras of south-east England and northern France (Rose, 1965). Characteristic species including Cirsium eriophorum and Orchis purpurea are found in both landscapes. Local botanical recording groups, including the Picardy branch of the Conservatoire botanique national de Bailleul (CBNBl), are essential to maintaining inventories and impacts of land use.

A chalkland scarcity recorded on the Somme: Orchis purpurea (Image: M. Storey,

We can still learn much from the history of botany that can inform its future.

- James & Andrew -  


De Vicq, E. (1883). Flore du Département de la Somme. Abbeville.

DEPG (2014). Records on 60 years of DMZ history & ecosystem. Department of Environment Policy, Gangwondo.

Hill, A.W. (1917). The flora of the Somme Battlefield. Bulletin of Miscellaneous Information, Kew 1917: 297-300.

Hill, A.W. (1919). Our soldiers’ graves. Journal of the Royal Horticultural Society 45: 1-13.

Leonard, M. (2011). Shattered earth. Military Times Magazine, April 2011. Available online

Mabberley, D.J. (2009). Exploring terra incognita. Science 324: 472. Available online

Pauquy, C. (1831). Statistique botanique. Flore du Département de la Somme et des environs de Paris. Amiens.

Rose, F. (1965). Botany on two coasts. New Scientist, 15 July 1965: 158-161. Available online

Stott, P.A. (1970). The study of chalk grassland in Northern France: an historical review. Biological Journal of the Linnean Society 2: 173-207. Available online

Wearn, J. (2015). Risking their lives to collect plants on the Salonika Front. The New Mosquito. Journal of the Salonika Campaign Society 1915-1918, 31: 8-14.

Wearn, J. (2016a). The power of poppies. Papaver. pp.98-101 in The botanical treasury: celebrating 40 of the world’s most fascinating plants through rare prints and classic texts (ed. C. Mills), André Deutsch Limited, London.

Wearn, J. (2016b). Seeds of change – polemobotany in the study of war and culture. Journal of War and Culture Studies 9(3).

Wearn, J. & Hudson, J. (2014). Lichens and war graves – from Kew’s Archives to the modern day. British Lichen Society Bulletin 114: 23-26.

Kew Specialist Certificate in Kitchen Garden Production

Course duration

One year (from September to September).


Students will work full-time within Kew’s Kitchen Garden.

Students will undertake a two week exchange with students from other horticultural establishments that have significant kitchen gardens. For example, NT Knightshayes, RHS Garden Wisely, Garden Organic’s – Audley End.


Students will attend appropriate Kew Diploma lectures linked to fruit and vegetable production.

What inspires a research idea?

Blog team: 
Alex Monro


Encountering giant oak forests

I have spent many years working in Central American forests, either documenting their diversity or managing and leading projects to help conserve them. One of the areas in which I have worked the most is the La Amistad UNESCO World Heritage Site which straddles the Costa Rica-Panama border. It is here that I first came across wet, high elevation oak forests, at 2,700 m. It was a magical and unexpected experience, suddenly arriving in a forest whose canopy consisted almost entirely of massive oak trees, 40 m in height, covered in dark maroon liverworts and bright red bromeliads. I had no idea that there were such oak forests in the wet tropics, and whilst I had seen small oak trees growing in semi-deciduous forests in Belize and El Salvador, they could not be said to constitute a forest.

Unique ecosystems

Later, on subsequent expeditions, we came across several wet, high elevation oak forests at between 1,900 and 3,100 m in Costa Rica and Panama. We made many collections and inventories from them. As a botanist with neotropical field experience, wet, high elevation oak forests struck me as unique on three counts:

  • Unlike most tropical forests, the canopy was dominated by a small number of species, almost all of which were oaks.
  • The canopy trees were of great stature; at altitudes close to the tree line (2,700 – 2,900 m above sea level) they often reached 40 m in height – much taller than forest at lower elevations.
  • Unlike tropical forests, the bulk of plant species diversity was in the epiphyte, groundstory and understory flora.

The fact that I had spent over a decade working in Central American forests and not come across these forests made me think that these ecosystems are poorly known, compared to cloud forest for example (or that I am very ignorant!).

Isolated and under-researched

On regional maps these forests are included in broader categories such as ‘wet montane forest’ (1) or ‘cloud forest’ (2) so you would not be able locate them on a map. Wet, high elevation oak forests are also harder to access and are most intact in places where there are fewer people, and consequently fewer roads.

We spent many weeks working in areas that were two days walk from the nearest dirt track, and where we could only rely on aerial survey maps. There are relatively few collections or surveys from these isolated areas, and as a consequence their biodiversity value is poorly known. Unfortunately, national agencies responsible for conservation do not have the data or awareness to monitor and protect these areas. This absence of knowledge means that these majestic ecosystems are vulnerable at a time when the world is changing quickly (3).

Developing an idea

Whilst working on a checklist of the vascular plants of La Amistad World Heritage International Park (4) and subsequently on an analysis of the species composition across a broad elevation gradient (5), Kew was designing its current science strategy. It quickly became apparent that there was scope to contribute to two of its headline Strategic Outputs: ‘State of the World’s Plants’ and ‘Tropical Important Plant Areas’ (6) by addressing some of the knowledge gaps for wet, high elevation oak forests. Specifically,

  1. How does species diversity and richness vary across this ecosystem, across its range?
  2. Are there abiotic drivers of this diversity that can be used to predict coverage in future climates?
  3. What is the conservation value and threat status of the vascular plants and myco-flora?
  4. How has the extent of this forest been impacted by land-use change, and where is it most vulnerable to future change?

So this was the birth of an idea and a concept for a project. The next stage was to identify potential partners to ensure that we had the capacity to address our aims, and that we were connected to the most relevant scientific communities and agencies responsible for managing or conserving these areas.  

Recruiting international expertise

The forests occur in Colombia, Panama and Costa Rica, so I set about contacting people I had worked with before in these countries in order to identify the most appropriate partners. This enabled me to find interested potential partners in Colombia (University of Bogota and the Humboldt Institute), Costa Rica (the University of Costa Rica [UCR] and National System of Protected Areas of Costa Rica [SINAC]) and Panama (the National Environment Authority of Panama [ANAM]).

Additional individual experts were identified, including scientists specialising in: wet, high elevation oak forest ecology (Maarten Kappelle, UNEP), mycology (Greg Mueller, Field Museum of Chicago; Kew’s Mycology group), vegetation analysis and species modelling (Nadia Bystriakova, The Natural History Museum, London; Kew’s Spatial Analysis Team; Kew’s Red Listing Team) and myself as member of Kew’s Americas Team.

What does the data show?

The next stage was to identify and evaluate the data-sets that we had already obtained. Thanks to our partners, we had access to vascular plant point (plot) data from Panama, Costa Rica and Colombia. It is not clear, however, whether all of the data is of the same resolution as our own, so we must investigate whether it will be compatible.

For fungi we would need to focus on the best studied ectomycorrhizal (relationships between fungi and certain plants) groups. But would this provide enough data to answer our third objective (what is the conservation value and threat status of the vascular plant and myco-flora)? If not, then it might be better to include fungi at a later stage and use the results of our vascular plant data sets to establish a sampling design for fungi. These are some of the many decisions that will determine the final content of a proposal.

Following this, and the stage that we are at now, we need to produce a draft concept note for distribution to the partners, and of course to accommodate their feedback as best we can.

Next steps

Once a proposal outline is agreed then we will need to identify a potential funding source. Fortunately, Kew provides support to scientists to help us to secure funding. Once the proposal has been approved by Kew’s Senior Science Team, the proposal can be submitted and hopefully funded!

- Alex -


1. Holdridge, L.R. (1967). Life Zone Ecology. Tropical Science Centre, San Jose.

2. Autoridad Nacional del Ambiente de Panamá (ANAM) & Corredor Biológico Mesoamericano del Atlantico Panameno (CBMAP) (2000). Mapa de vegetación de Panamá. Instituto Geográfico Nacional Tommy Guardia, Panama City.

3. Kappelle, M. (2006). Neotropical montane oak forests: overview and outlook. In: Ecology and Conservation of Neotropical Montane Oak Forests, ed. M. Kappelle, pp. 449–467. Springer-Verlag, Berlin.

4. Monro, A.K., González, F., Santamaría, D., Chacón, O., Rodríguez, A., Solano, D., Zamora, N., & Correa, M. (submitted). A first checklist to the vascular plants of La Amistad International Park (PILA), Costa Rica Panama. Phyotaxa.

5. Monro, A.K, González, F. & Bystriakova, N. (submitted). Do floristic inventories provide data useful for understanding tropical plant assemblages? A case study of La Amistad World Heritage Site. Biotropica.

6. Kew Science Strategy (2015) Available online

Contact us about your event

By choosing yes you confirm that you agree to Kew Events using your information for the stated purpose. Kew Events agree that it will respect the privacy of the personal data you supply to us and the records that we retain relating to you. We guarantee not to pass your information on to third parties.