Leigh Hunt, RHS Principal Horticultural Advisor

Greener Streets: Better Lives

Milton Keynes in Bloom 2011

Leigh Hunt, Principal Horticultural Advisor,

RHS Garden Wisley in Surrey

• 50 staff working in Science and Advice teams

• Has partnerships with Reading and Sheffield Universities

Green Streets: Better Lives talk outline

• Why do gardens, parks and green space matter?

• The benefits of plants

• Intro to RHS campaign, Green Streets: Better Lives

• Using plants to get the benefits (but not how…)

Members of Three Close Tenants

Loughborough in Bloom 2012

Kings Heath

in Bloom,

Birmingham, 2012

Why do gardens, parks and

green space matter…?

It was all an assumption…

Green space is good!

• Science-based evidence for this?

• How we get the benefit?

• What should we do more of?

• What should we do less of?

Why are urban gardens important?

The potential scope

• Up to half of a town’s area is greenspace

• 20%(London) to 23%(Sheffield) of the town’s area is gardens

• UK gardens contain almost 29 million trees (i.e. ~ 25% of all trees occurring outside woodlands)

Our potential collective input

• Almost 90% of UK residents live in urban areas

• 22.7 million households (87% of homes) in the UK have access to a garden (Thompson et al., 2004; Davies et al., 2009; Cameron et al., 2012)

What we grow in our greenspaces and

how we manage them has a big impact!

A volunteer working on the flowerbeds in

Princes Street Gardens, Edinburgh, July 2013.

Dr Tijana Blanuša

RHS Senior Scientist

rhs.org.uk/urbangreening

Why are urban domestic gardens important?RHS Science review

• Remarkable depth and range of

benefits that gardens provide in

urban areas

• Domino effect – one garden is not

much, but together – gardens are

nearly half of urban green space

• 4 key benefit areas

What are the benefits?

Bloom and It’s Your Neighbourhood

• Greening friendly (if not a frenzy)!

• It’s challenging to do more… time, resources, skills, other risks…

45% of Local Authorities are considering either selling parks and

green spaces or transferring their management to others

(The State of UK Public Parks 2014 – Renaissance to Risk?)

• Justifying green… not just pretty… solid reasons to do.

1. Moderating urban temperature

1. Moderating urban temperature

• Air conditioning: Plants help cool the air

• Trees and hedges can reduce heating costs and energy consumption by up to 30%

Get the benefit

• Get planting! A 10% increase in planting would

help control the rise in summertime air temperatures

predicated with climate change

• Trees, in particular, shade helping to heat islands

• Deciduous trees can allow more heat in during winter

• Well positioned hedges and trees can deflect wind

1. Moderating urban temperaturegreen walls and climbers

• Moderating temperatures locally

• Insulation for buildings

• Can cut heating and cooling bills

Room for your 10% extra?

RHS Science

Urban greening research

Alternatives to Sedum on green roofs:

Can broad leaf perennial plants offer

better 'cooling service'?

Building and Environment, Blanusa et al., 2013, pp59, 99-106

Species/

surface

Soil

temperature

(oC) @ -1

cm

Air

temperature

(oC) @ 10

cm

Stachys

byzantina

22.2 24.8

Sedum mix 34.2 25.1

Bare soil 37.1 25.9

LSD (d.f.) 1.09 (149) 0.32 (149)

Why worry about this?

Climate Change

Predictions of Climate Change

• Temperatures are rising, making gardens

drier

• 2020 – 1°C rise in temperature

“major impacts on ecosystems”

• 2050 – 2°C rise leads to half the days in

August being above 30°C

• 2080 – 2 to 4°C rise could bring days that

exceed 40°C. 20 to 50% less rain in summer,

and only 10 to 30% more in winter

Plants = Climate change mitigation!

Change in Summer Mean Temperature: 2020s

Change in Summer Mean Temperature: 2080s

2. Keeping our towns ‘above water’

2. Preventing flooding

• Urban gardens help keep our cities

‘above water’

• Garden plants and trees intercept

intense rain, slowing run off, reducing

pressure on drains

• Unlike hard surfaces, the soil in gardens

absorbs rain

Paving of urban and suburban areas

• 13% increase in

impervious

surfaces over 30

years in

the city of Leeds

• 75% of which was

due to paving of

front gardens12% drop in vegetation

Why are public green spaces important?

1. Domestic gardens are under threat

Hard surfaces in gardens increase by twice the area

of Hyde Park every year (London Assembly, Crazy Paving 2005)

(Smith, 2008, GIGL).

Hard

surfaces

shed 50%

more rain

water.

3

Flooding –

cost the

country

£3.2 billion

in 2007

Change in Summer Mean Rainfall: 2020sChange in Summer Mean Rainfall: 2020s

Change in Summer Mean Rainfall: 2080s

© Crown copyright Met Office

Hot off the

press....

Seasonal

Changes in

Extreme

Rainfall Events

Winter

Summer

What can we do?

As groups, or by encouraging others

• Keep paving to a minimum

• Drain into beds, borders and lawns

• Install green roofs and plant trees to help slow runoff

• Swap hard surfaces for planting

3. Supporting biodiversity

3. Supporting biodiversity

• Urban greenspace:

one of Britain’s key nature reserves

• Urban domestic gardens of all sizes

support a substantial range of wildlife –

could be 260 species (Jenifer Owens 2010)

• Some animals are now more common in

cities, particularly gardens, than rural areas

To help:

• Get planting: berries and flowers

• Plants as homes and shelter: trees,

hedges, shrubs

• Wildlife friendly additions: ponds,

bird baths, bird boxes etc.

• 740 m2 Garden in Leicestershire

• 1602 insect spp

• 121 other invertebrates

• Parasitic wasps – 20 new to UK – 4 new to science

• 21% of UK insect spp

Owen J (2010) Wildlife of a Garden: A Thirty-Year Study. Royal Horticultural Society, London.

Owen (2010) – Wildlife of a Garden

Origins of plant assemblages

Near Native

Exotic

UK Native

RHS Science:

Plants for Bugs

80,000 specimens and more than 400 species of

invertebrates collected, counted and identified

Initial data analysis shows:

• Native is not always best

• There are differences between the

treatments and, different invertebrate

groups show different preferences

for different treatments

• Results will be published summer

2014 onwards

RHS Science:

Plants for Bugs

RHS Perfect for Pollinators

rhs.org.uk/perfectforpollinators

4. Supporting human health

4. Supporting human health

Scientific evidence

• Gardening eases stress

• Gardening encourages sustained

and cardiovascular exercise

• Reduced incidence of illness

• Increased self-esteem,

a feeling of achievement

To get the benefits:

• Get out and garden!

• Create a great greensapce

• Be creative… plan and

have control

RHS Science

4: “green exercise”

• Collaboration between the RHS

and Coventry University

• It is often said that gardening is

effectively “green exercise” but

there is little evidence

• Study will examine the muscle

strength, bone health, cardio-

vascular performance and mobility

of gardeners, and non-gardeners,

to see if there is any correlation

between health benefits and

gardening activities

RHS Science

5: Restoration from gardens

• Collaboration between the

RHS and University of Surrey

• Any difference between

gardens and naturalness

(and create a measure)

• Which garden features help?

• Provide recommendations for

designing natural spaces

• Due October 2016

5. Reducing pollution

• Rough and hairy! These

characteristics trap pollution

• Otherwise, clip your plants to create

dense structures as this also helps.

How to use plants:

• Plant a tree, or hedge, particularly

along the street edge.

• Use hornbeam, hawthorn, plane

western red cedar (Thuja) for

maximum benefits

• Dense vegetation can help –

but not always appropriate

Three negatives of gardening/greening

Water use Carbon cost

Removing existing flora and wildlife

habitat

Getting the benefits

Green Streets: Better Lives

It’s all interlinked – the greenspace

• Air temperatures* /

building insulation

• Pollutant trapping**

• Rainfall capture

• Carbon cost

How can we optimise multiple services

by plants?

*Blanusa et al., 2013, Building and Environment, 59, 99-106

**Fantozzi et al., 2013, Environmental Pollution, in press.

Greenspace/

domestic

gardens

Street

trees

Green roofs

and walls

Ecosystem services

1. More is more!

More is more Case study 1

Larkhall Park Community Garden

Formerly an area for drug users,

rough sleepers and gangs, an

unused quarter of the park was

transformed by gardening charity

Thrive. The new community hub

hosts weekly gardening and food

sharing activities.

More is more: Case study 2

Supermarket and Manchester

• Living wall and green roof at Bracknell’s Waitrose

supermarket, Bracknell

• Levenshulme Market, a

community-run social

enterprise, with funding from

Manchester City Council

for a green roof and a mural, on the shipping container

where they store a generator.

2. Green is better than grey

• No plants; no benefits!

• Permanent planting is even better (reduced water and

carbon cost)

Members of Three Close Tenants

Loughborough in Bloom 2012

Kings Heath

in Bloom,

Birmingham, 2012

Green is better than grey Case study 3

Concrete bollards to garden, Wroxham

• Residents were refused permission to remove unwanted

bollards so adapted them into their own green space

3. Get connected

• Connectivity of greenspace is important

• Wildlife corridors

About 25% of the land in cities OR half the greenspace

Get connected Case study 4

Garden revamped in Ross-on-Wye

• Volunteers transform unloved corner of park, removing

hard-standing and adding diverse planting

Get connected Case study 5

Uttoxeter Station

• Project by: East Midlands Trains, North Staffordshire

Community Rail Partnership and Uttoxeter station

volunteers to create a waiting area for passengers.

• £13,000 grant from Network Rail’s National Stations

Improvement Programme.

The benefits of greenspace are huge:

Climate change resilience for towns and cities

Flooding, temperature moderation, carbon sequestration

Supporting human health

Sustainable communities

‘Nice’ places to live – high quality environments

Be mindful of negative impacts

To get or demonstrate the benefits:

» More is more!

» Green is better than grey

» Get connected

Green Streets: Better Lives

RHS Advisory information online

Leigh Hunt, RHS Principal Horticultural Advisor

Green Streets: Better Lives

Milton Keynes in Bloom 2011