London: garden city? Investigating the changing anatomy of London’s private gardens, and the scale of their loss Introduction

London: garden city? Gardens are part of London’s green ownership, as well as being subject infrastructure1 - multifunctional to passing trends and fashions. A research project by Chloë Smith on behalf of London Wildlife Trust, spaces, fulfilling multiple roles. A Greenspace Information for Greater London and the Greater London Authority. key part of London’s green cover, An understanding of the current they form important wildlife habitat, status and the changing uses of both individually and as part of a gardens is important for policy larger garden network. People can makers in London. In response to benefit from direct contact with this need, London Wildlife Trust, the natural world in their gardens. Greenspace Information for Greater They are also the places where London (GiGL), the Greater many Londoners play, grow food or London Authority (GLA) and the simply escape from the hustle and Royal Society of Wildlife Trusts bustle of the city. commissioned this research project, to establish the structure and Gardens make up much of As they cover nearly a quarter composition of London gardens and London’s green space. They are of Greater London, gardens are identify key land use changes over a valuable for both people and also important with regard to period of eight years. wildlife because they provide a the predicted impacts of climate significant amount of London’s change by decreasing flood risk The research generates a baseline open space and habitat. Climate and reducing the urban heat island of information on London’s change means that the extent effect. gardens and their role for people, and quality of gardens may wildlife and the environment. It become increasingly important But gardens are not an develops transferable methods as they also have a role to homogeneous resource. Mostly of investigation and interrogates play in keeping the city cool privately owned, they can have some key lines of enquiry from and in preventing surface- variable management and stakeholders. water flooding. But, until now, Acknowledgements the character and scale of Many thanks to all those involved in the research. Dave Dawson London’s gardens as a green In particular this research project: collaborated significantly on methods, analysis and presentation. space resource have not been • establishes the current garden resource in London Guidance and editorial assistance were provided by Elaine Hughes, fully documented. This report • quantifies recent land cover changes in London’s gardens John Archer, Mathew Frith, Mandy Rudd, Peter Massini, Matt Thomas, reveals the changing anatomy • provides evidence for campaigns, policy and other action to promote Catherine Harris, Barnaby Dawson, and others. Matt Davies contributed of London’s private gardens. and protect gardens as an important environmental asset the original idea as well as project support. Dave Allen and other It investigates the scale of the volunteers generously gave their time and access to their gardens. changes to their extent and KEY MESSAGES composition, in particular the • gardens in London have changed significantly in recent years This project was made possible by a grant from the Royal Society of loss of garden. • garden vegetation - including lawns and garden trees - is being lost Wildlife Trusts (RSWT). • the losses are due primarily to changes to garden design and management © Chloë Smith 2010 • while development can have a big impact locally, the loss due London Wildlife Trust to development across London is relatively small Greenspace Information for Greater London • collectively these losses have implications for London’s wildlife and our Greater London Authority ability to adapt to the impacts of climate change

Editorial team: Helen Babbs, Mathew Frith, Pete Massini and Chloë Smith This document is a summary of a more detailed research report which can Design: Metalanguage Design be found online at www.wildlondon.org.uk and www.gigl.org.uk

1 Green infrastructure The open environment within urban areas, the urban fringe and the countryside. It is a network of connected, high quality, multi-functional open spaces, corridors and the links in between that provide multiple benefits for people and wildlife. 3 Cities Revealed aerial photography copyright Cities Revealed aerial photography copyright The Geoinformation Group 2008 The Geoinformation Group 2008

Headline facts and figures Studying Greater London’s gardens

The anatomy of London’s gardens today This report documents a cover composition. It also Left: area in east London where London-wide investigation of addresses key changes in that gardens represent the only • 37,900 hectares (ha), approximately 24% of Greater London, is comprised of private, domestic garden garden land cover, outlining composition during the study significant green space, 2006-08. land.2 the current baseline data, the period. This information was Above: large back and relatively number of gardens found in collated by comparing two sets large front gardens in Croydon, • Of that garden land, 57% - or 22,000ha - is vegetated cover (lawn, tree canopy and other vegetation). Greater London, and inferring of aerial photographs taken at showing more diverse land covers Therefore, approximately 14% of London is garden greenspace.3 a typical garden’s land different times. in these bigger gardens, 2006-08.

• There are an estimated 3.8 million individual private garden plots (counting front, back and other kinds separately) Garden ground cover findings The total area of land classified by this research to be 22,000ha, This study has found that back • There are estimated to be 2.5 million garden trees in London. as private garden in London is approximately 14% of London. gardens make up most of around 37,900ha (based on London’s garden area, 24,000 ha, Ordnance Survey MasterMap). The total number of garden plots approximately 63% of the total. Changes in the composition of gardens This is approximately 24% of the found in London is estimated to be Front gardens contribute to most of city’s total area. In the context of 3.8 million. There are roughly equal the remaining garden land, 9,400 As a result of garden design and management other UK cities, the proportion of numbers of front and back gardens, ha, approximately 25% of the total the capital that is domestic garden in the order of 1.8 million of each, area. ‘Other’ gardens make up the • The area of vegetated land present in 1998-99 had dropped 12% in 2006-08, a loss of 3,000ha. isn’t unusual. Of course, not all of with 280,000 ‘other’ gardens5. This final 4,600 ha, 12% of garden land this land is vegetated. The total means there are about 2 million area in London. • On average, an area of vegetated garden land the size of 2.5 Hyde Parks was lost each year. area of actual vegetated land in dwellings with associated private London’s gardens is estimated garden space. • The amount of hard surfacing in London’s gardens increased by 26% or 2,600ha.

• The area of garden buildings increased in area by 55% or 1,000ha. Land cover was determined by comparing colour overlayed by garden polygon boundaries from • The amount of lawn decreased by 16% or 2,200ha. aerial photographs taken between 1998 and Ordnance Survey Mastermap® Topography Layer. 1999 with ones taken between 2006 and 2008. A polygon is a topographical feature in GIS with • Overall vegetation in gardens decreased by 12% or 3,000ha The images show the area covered by lawn, tree an enclosed boundary. canopy or hard surfacing in a garden. The paired As a result of development requiring planning permission sample allowed land cover change to be examined, Greater London’s garden land was split into four while the most recent photographs also provided kinds of polygons: • An average of 311 reported housing developments per annum occurred on private garden land each year.4 information about the current cover for Greater 1. front gardens London. 2. back gardens • On average, 500 gardens, or part gardens, were lost to development per year (we don’t know how many 3. ‘other’ gardens (neither back nor front) new gardens were created in association with development) Photographs were stored and displayed in a 4. front and back gardens mapped as one Geographical Information System (GIS) and combined polygon, which were then split in two

5 2 The land studied included “private residential gardens” as identified within Ordnance Survey MasterMap Topology layer ‘Other’ gardens are those rare plots that could not be classified as front or back gardens, for example 3 Area, percentage and count estimates are presented to two significant figures throughout the report to reflect precision those that are shared by a private flats building. 4 4 This relates to a separate study period covering three financial years between April 2005 and March 2008 5 Estimated break down of London’s overall Estimated break down of London’s overall garden area, by land cover type garden area, by garden type There’s an average

1% 1% of 1 tree in every

% 7 12% back garden 18% 25% (totalling 1.9 million 33% % 11 trees), and 1 tree in every fifth front 63% 29% garden (totalling 0.4 million trees). The remaining 0.3 Sheds, garages Back gardens u Hard surfaces u & greenhouses u million trees are Changes in composition investigated u Lawn u Side passages u Front gardens found in gardens The total area of vegetated As expected, hard surfacing covers land (lawn, tree canopy, other a significant area of London’s u Tree canopy u Other u Other classified neither vegetation) in London’s gardens front gardens – 5,900 ha. This is approximately 22,000ha. This figure updates earlier findings in Shrubs & herbaceous as front nor back, u borders is 57% of the city’s garden land the 2005 Crazy Paving6 study averaging 1 tree per resource. which estimated a much lower total ‘other’ garden. area for London (3,200 ha of hard On average, 6m² of vegetation has surfacing). 47% of garden hard been lost for every front garden in surfacing is found in front gardens, The anatomy of the average garden revealed London and 11m² of vegetation has though they only form 25% of been lost for every back garden. London’s total garden space. The mean front garden size in five front gardens. Tree canopy in London’s average The largest (and statistically London is estimated to be 56m2, gardens covers an area of 6,700ha, significant) reduction in total area An area of vegetated garden back gardens 150m2, together which represents 4% of London. front garden is 56m² relates to garden lawns, decreasing land equivalent to 21 times 200m2, and ‘other’ gardens 170m2. Some of this canopy cover is by 2,200ha, a 16% loss, overall. the size of Hyde Park was lost overhang of non-garden trees, like The biggest increase in area during between 1998-99 and 2006-08, On average, 63% of a front garden street trees. London’s average the study period relates to hard- representing 3,000ha or a 12% is covered by a hard surface, with back garden is surfacing (patios, paving, decking, reduction. This constitutes an a little lawn, other vegetation and There is a considerable difference etc), increasing by 2,600ha, a 26% annual loss of an area two and tree canopy. On average a back in average garden size between the 150m² gain. The cover of garden buildings a half times the size of Hyde garden is 33% lawn and 22% hard boroughs. Outer London boroughs, (typically sheds, glasshouses etc. Park. cover, with a larger area of tree such as Bromley and Barnet, have almost always in back gardens) canopy and other vegetation when the largest average sizes, while inner The average front increased by 1,000ha, a 55% compared with front gardens. We London boroughs, like Hackney increase. can infer that the typical front or and City of Westminster, typically garden is 63% hard back garden in London would fit have small gardens. Overall, small surfacing these descriptions. gardens are much more common in Top: a highly designed garden London than large ones. Left: decking There are estimated to be 2.5 Right: front gardens lost to parking million garden trees in London. Unsurprisingly, there is a greater The average back Back gardens include about 1.9 variety of habitat types to be found garden is 33% lawn million trees, front gardens 0.4 in large gardens than in small ones. million and ‘other’ gardens 0.3 It seems likely that a block of large and 22% hard million. So on average there is one gardens will have a greater diversity surfacing tree per back garden and every of habitat than a similarly large ‘other’ garden, and one tree in every block of small gardens. 6 Greater London Assembly Environment Committee, 2005 6 7 the variety of wildlife seen in neighbouring gardens.

There is also an increasing demand and desire for locally grown food. London’s gardens could contribute to meeting this demand (as they have done in the past) but only if the quantity and quality of the resource, particularly a healthy garden soil, is maintained.

Left: song thrush © Tajinder Assessing the impact of changing design and Lachhar management Examining the impact of development Centre: bumblebee on teasel © Metalanguage Design The research suggests that potential loss of wildlife habitat The research also looked at or brownfield land. So, we are The loss of around 6ha of Right: common frog © Tony London’s gardens are subject to during the period. The loss of each residential housing developments confident that our findings would vegetated garden land to Canning some significant changes to their tree, hedge or square metre of on garden land that required not be shaken by our inability to housing development on Below: hedgehog © Richard composition which might have more lawn is a loss not only of the plants planning permission and had study this. gardens each year, and a gain Burkmar telling environmental impacts than involved, but also for the wildlife that been implemented over a three of an equivalent area of hard previously thought. depends upon them for food and year period between April 2005 Unsurprisingly, there is a land cover, isn’t particularly shelter. London’s gardens provide and March 2008. It investigates significant difference between land notable at a pan-London The increase in hard surfacing is valuable habitat for a range of wild the consequences of these cover before and after housing scale. At this rate it would 11m² of vegetation a particular concern. Many paving plants and animals including birds, developments and estimates the developments granted planning take 30 years to lose 1% of materials used in domestic situations mammals, amphibia and a huge impact they’ve had on land that was permission are completed on London’s garden vegetated was lost from the are impermeable resulting in excess variety of invertebrates. Notable previously identified as garden. garden land. Prior to development land to housing developments. average back garden, water running into sewers and drains, species include hedgehog, house there is proportionately more Nevertheless, on a local scale, rather than soaking into the land. sparrow, common frog, and stag There was an average of 311 vegetated land cover (tree canopy, the impact may be profound an 11% reduction beetle. Gardens are becoming an known housing developments per lawn, other vegetation) than in terms of wildlife resources, in cover since 1998- In October 2008, planning important resource for conserving annum on private garden land in there are hard features (patios, flood drainage and climate regulations were changed so that some of these species. London during the study period. side passages, buildings). After change adaptation. 99 (representing 8% planning permission is required The land subject to development development, the proportion of for paving of front gardens, unless is estimated to have included at vegetated land decreases, and hard of the average back the paving is permeable. But this least part of 500 existing gardens features increase. garden area). research shows that many front each year, and, while development gardens have already been paved led to an overall gain in the number There is an average increase and a loss of permeability as a of gardens per year, the amount in hard-surfacing and buildings 6m² of vegetation consequence of hard-surfacing may of garden greenspace actually (including the house footprint) be an issue for back-gardens too. decreased significantly, because of 210m2 per development. was lost from these new gardens were very small This, coupled with an average the average front Hard surfacing also stores more resulting in a net loss in garden cover. loss of 200m2 greenspace per solar energy than vegetated development (remaining loss was of garden, a 24% surfaces. This energy is released New gardens are created in Greater miscellaneous surfaces), represents back into the atmosphere as the air London every year, but this study a loss of wildlife habitat and fall since 1998-99 temperature cools. This contributes On an individual scale, changes was unable to fully quantify this. permeability to water. (representing 11% to the heat island effect, particularly in the composition of garden land However, this ‘new’ garden land at night during the summer months, can have a significant impact on does not necessarily result in a On average 500 garden trees of the average front exacerbating the adverse impacts of the biodiversity value of a garden. net increase in garden land or an are removed each year due to garden area). summer heatwaves. On a larger scale, such as a block increase quality wildlife habitat; development of houses on gardens. of suburban gardens, significant it is likely to be made mainly from This means that 1.5 garden Top: blue tit © Bertie Gregory The changes in garden composition changes occurring somewhere existing gardens or as part of trees are lost on average per Above: comma © Adam Wilson detected in this study indicate a in the block will adversely affect new development on greenfield development project.

8 9 Conclusions Further information

The research confirms that the a London-wide scale there may Ecological principles tell us that Visit www.wildlondon.org.uk and To explore what wildlife has been For further information on wildlife composition of London’s gardens is be impacts at a local level. The these losses of wildlife habitat do www.gigl.org.uk to download a recorded in London’s gardens you gardening across the UK go changing at a significant rate – an research indicates that policies not simply displace the wildlife to copy of the full Garden Research can visit ‘What’s In My Back Yard?’ to The Wildlife Trusts and the area two and a half times the size in the replacement London Plan other places, but rather they lead Project, its findings, conclusions (WIMBY) at www.gigl.org.uk RHS’ gardening website www. of Hyde Park of vegetated garden are appropriate by recommending to losses of wildlife. A garden is not and a complete set of references. wildaboutgardens.org.uk land is being lost every year - very that Boroughs may introduce a only valuable as a small privately To find out how you can do your bit largely as the result of very many presumption against development owned space, but as part of a To find out more about creating a for climate change adaptation and small changes made to individual of back gardens where this can be larger London-wide landscape, and wildlife and climate friendly garden garden wildlife go to www.london. gardens. And the amount of hard locally justified.7 Local approaches has a role in supporting biodiversity go to www.wildlondon.org.uk/ gov.uk/trees surfacing in the capital’s gardens to the design of front gardens at a neighbourhood scale. gardenforalivinglondon has grown significantly - by over a including the need for permeable quarter during the research period. surfaces should also reflect the Collectively, London’s gardens Developments on garden land that broader policies of the London Plan. might also play an important role London Wildlife Trust is the require planning permission have a in adapting to climate change. The only charity dedicated solely to far less significant impact, although The project highlights the scale of research strongly indicates that protecting the capital’s wildlife this shouldn’t be under-estimated. the garden resource in London and these functions of gardens may be and wild spaces, engaging documents the impact that many being compromised by changes to London’s diverse communities Although loss of garden land due individual garden management design and management. through access to our nature to development needing planning decisions have on the composition reserves, campaigning, permission is not significant on of that space across the capital. volunteering and education. www.wildlondon.org.uk Recommendations Greenspace Information for It’s never been more important This research highlights that the Greater London is the capital’s that Londoners understand the impacts of garden design and environmental records centre. It value of our capital’s gardens. A management on the environmental collates, manages and makes well managed network of gardens roles of gardens is an issue that available detailed information on stretching across the capital would needs to be addressed. It is not the London’s wildlife, parks, nature provide essential wildlife habitat and role of the Mayor or environmental reserves, gardens and other open offer important environmental benefits organisations to dictate how spaces. in response to climate change. Londoners should manage their www.gigl.org.uk back gardens. Nevertheless, It is Existing planning regulations have important that Londoners are made The Greater London Authority is a removed permitted development more aware of the collective value strategic authority with Londonwide rights which allowed for the of their gardens for wildlife and role to design and deliver a better paving over of front gardens with climate change adaptation and that future for London. impermeable surfaces and this the decisions they make may have www.london.gov.uk has gone some way to addressing long-term consequences for local some of the issues highlighted by this environmental quality. Royal Society of Wildlife Trusts research. Front gardens are regarded There are 47 local Wildlife Trusts as de facto part of the public realm across the UK, the Isle of Man & (albeit private land) and therefore it Alderney, working for an environment is appropriate for planning controls rich in wildlife for everyone. The to constrain the ways these spaces Wildlife Trusts are the largest UK are managed. These regulations do voluntary organisation, dedicated not apply to back gardens. However, to conserving the full range of the normal planning controls do exist to UK’s habitats and species. prevent unacceptable development www.wildlifetrusts.org Above: gardening © Bertie in back gardens, and many trees in Gregory back gardens will be subject to Tree Right: garden © Richard Burkmar Preservation Orders. Above: foxglove © Metalanguage Design Back cover: outer suburban rear gardens © Mathew Frith 7 proposed Policy 3.5 ‘Quality of Design of Housing Developments’ 10 11