The 800 Pound Gorilla in our
Backyards
Why Focus on the Suburban
Lawn?
• A high level of American’s
interaction with the
environment occurs here –
need to teach the right lessons
• Third largest “crop” in the
U.S. – and growing!
• Especially important for urban
watersheds like the N.W.
Branch – can be the major
source of pollutants
The Lawn Ecosystem in the U.S.
• Imported from Europe
– is an artificial
ecosystem
• Only able to become
widespread because of
technological
innovations
The National Costs of the Lawn
Ecosystem
• Americans spend Percent Lawn Maintenance Expense for
the United States
25 Billion dollars a
Seed
Ot her
year on
2%
8%
landscaping
• $100 for every
Equipment
20%
person in the
country
Labor
Pest icide
60%
• $380 for every
3% Gas
3%
Fert ilizer
household
4%
The Costs Associated with Lawn Care
Landowner
Total Cost
Cost/Person
Cost/Hectare
Homeowners
$25 Billion
$379.00
$2,500/hectare
Farmers
$57 Billion
Not available
$420/hectare
• The average homeowner spends six times more per
hectare on yard care than the average farmer spends
tending crops.
The Ecological Footprint
Concept
An ecological footprint
is a way of translating
the environmental
impacts of an activity
into the land needed to
sustain that activity ad
infinitum
Ecological Footprint of the Lawn at
the National and State Level
Input
Total Energy Use (GJ)
Total Footprint (Hectares)
Footprint per Hectare
(Hectares)
Pennsylvania
National
Pennsylvania
National
Pennsylvania
National
Land
N/A
N/A
548,350
11,600,000
1.0
1.0
Water
7.7x105
6.1x106
9,625
76,500
0.018
0.007
Fuel
6.8x106
9.1x107
85,000
1,138,000
0.155
0.098
Machine
Production
Fertilizer
Production
Pesticide
Production
Total
8.8x105
4.4x107
11,000
550,000
0.02
0.047
1.4x106
1.32x107
17,500
165,000
0.032
0.014
4.8x105
4.8x106
600
60,000
0.001
0.004
1.03x107
1.59x108
672,075
13,589,500
1.226
1.170
•Nationally we use enough energy in lawn care every year to supply 1.5
million American households with power for a year.
•1/5 hectare of land is needed to provide enough energy to care for one
hectare of lawn
Estimated National and State Level
Air Pollution from Lawn Care
Input
Particulate
Matter per
Hectare
NOx and
HC's per
Hectare
Total CO
per
Hectare
Total
CO2 per
Hectare
Total NH3
per
Hectare
National
11.5 kg/yr.
403 kg/yr.
1,910
kg/yr.
806 kg/yr.
0.017
kg/yr.
PA
14 kg/yr.
540 kg/yr.
2,537
kg/yr.
1,082
kg/yr.
0.032
kg/yr.
• Although used infrequently, lawn equipment creates a
significant amount of air pollution because small engine
emission standards are more lenient than large engine
standards.
• Lawn equipment produces between 10-30 times as much
air pollution per liter of gas as a car.
The Lawn’s Impact on Biota
•Very few studies on
this topic
•Studies show that
urban growth favors
generalist and exotic
species
Comparison of Biota with
Different Maintenance Regimes
Maintenance
Regime
High
Maintenance
Medium
Maintenance
Low
Maintenance
Number of
Plant Species
Found
2 species
5 species
16 species
Percentage of 0 percent
Native
Species
Found
0 percent
56 percent
Impacts of Lawns on Soil & Water
• 1/5 of all pesticides are
used on lawns – 10x
higher than farmer’s use
• 10 percent of water
pollution comes from
lawn care
• 1/3 of household water
use is used in lawn care
Runoff and Soil Loss
• Rain water infiltration is
2.5 greater in natural
fields than the compacted
lawns of suburbia
• Reduces groundwater
recharge
• Makes streams more
flashy
• Increases erosion rates
What to do?
Solutions Grow from
a Sense of Place –
Design for the
Place Where You
Live
Use poorly draining land as
a pond or install a rain
garden there
What to do?
Design and maintain
yard using ecological
accounting
Example: Integrated pest
management vs. pesticides
What to do?
Design and maintain
yards with Nature
instead of against
it
Example: yard waste –
compost vs. landfill
What to do?
Make nature visible
•People become interested in
nature through their yards &
parks
•Helps them make the
connection between
themselves and the
environment around them
Concrete Examples
• Rain Barrels
• Composters
More Examples
• Urban Shared Gardens
• Rain Gardens
Still more
• Reduce lawn sizes
• Eliminate exotics/plant
perennials & natives
More Examples
• Green roofs
• Plant trees