cross posted at Conceptual Guerilla
Now that I have your attention, suffice it to say that our default landscape choices, turf grass and non-native trees and shrubs, increase our dependency on Middle Eastern oil, increase our patronage of Big Oil, and by extension indirectly supply Middle Eastern terrorist organizations, including Al
Quaeda with petrodollars. Not only that, but they contribute millions of pounds of greenhouse gases, promote weeds and undesirable invasive plants, contribute to the destruction of the protective wetlands along the Gulf Coast, and other natural areas, contaminate ground and surface water with pesticides and excess nutrients, waste scarce groundwater resources, waste money, and contribute to increased surface water runoff and flooding. With spring just around the corner and people thinking green, we will touch on the costs of our current landscape paradigm and discuss an alternative sustainable landscape model that heals the land, conserves scarce resources, and is arguably more attractive.
First of all, a little quiz:
What landscape treatment has the following characteristics? :
• Used in nearly all residential, commercial and industrial development regardless of local climate and site conditions.
• Can contribute over 1,000 lbs per acre of greenhouse gases each year based on the professionally recommended maintenance practices in the Midwest U.S.
• Uses 325,000 gallons of water per acre (based on 12 weeks of watering/year)
• Increases water runoff by 10 to 100 times that of natural forested or prairie land.
• Increases nitrate and phosphate runoff up to 100 times that of natural land.
• Increases groundwater nitrates and phosphates by three to four times that of natural land, leading to contaminated ground water and "blue baby" syndrome.
• Burns over 600 million gallons of gasoline and diesel fuel per year to provide upkeep.
• Covers over 30 million acres of land in the U.S – more than most remaining high quality examples of natural area east of the plains states (prairie, old growth forests east of the Mississippi River, un-degraded wetlands, oak savanna).
• Can cost a do-it yourself homeowner nearly three times the annual upkeep cost of a sustainable or native landscape, and commercial areas up to four times the cost.
• Annual upkeep costs from $900-1000 an acre for do-it yourself homeowners up to $6000 an acre for high-end contracted work.
• Requires up to 120 hours of labor (three typical work weeks) per acre per year to maintain – four times the labor to maintain a native or sustainable landscape.
• Contributes to soil compaction, inappropriate land use and the waste stream.
• Promotes nuisance bird species such as starlings, English sparrows, and giant Canada geese.
• Can contribute the equivalent hydrocarbon pollution in one hour of maintenance as a car driven 25 to 200 miles depending on the type of equipment used.
• Uses a minimum of two to four times the fertilizer and pesticide per acre as crop land.
For more information on lawn impacts, see: environmental impacts of intensive lawn maintenance.
If you answered the turf grass lawn, you are correct. Lawns are a significant factor in causing local, regional and national environmental problems ranging from algae blooms and degraded water quality in the neighborhood detention pond, to accelerated aging of ponds and lakes, to reduced clarity of streams and loss of fish habitat, to increased flooding, and finally the vast dead zone that has developed at the mouth of the Mississippi River in the Gulf of Mexico, a direct result of the excessive nitrates and phosphates that have overloaded the system. Dead zones have also developed in the Chesapeake Bay as a result of nutrients from urban landscapes and farmland. Natural areas such as the wetlands around the Mississippi Delta are also degraded as they "grow themselves to death" from the excessive nitrate and phosphates discharged from millions of lawns and landscapes. Only a few weedy species such as reed canary grass, giant reed and hybrid cattails can survive the oversupply of nutrients, simplifying the system and destroying a stable, resilient habitat that has persisted for thousands of years, building protection for the Gulf coastline.
On a more local level, one can see the inadequacy of our chemical soaked, turf dependent landscape in the detention ponds and creeks with collapsing banks as seen in the picture above, the cloudy, lifeless waters, the torrents of rainfall that run off the land rather than soak in, the falling levels of groundwater, that we see in the picture of the marooned dock in this dried up Illinois pond and the choruses of frogs in the spring that have fallen silent, while the roar of lawn mowers permeates the landscape every day and "lawn service" companies of all sizes clog residential streets. Weedy invasive plants such as buckthorn, purple loosestrife, honeysuckle, Chinese tallow tree and Siberian elm testify to the desire of our conventional landscapes for the cheap, the exotic and the fast growing, and diseases and pests such as Dutch elm disease and Chestnut blight, among others, have resulted from our desire to import landscape plants from far away, rather then locally sourced, adapted plants.
An example of the land abuse inherent in our current landscape model can be seen in this picture of a salt-blasted parking lot island at a Wisconsin Wal-mart. Note that this chemical cocktail of eroding soil and failing turf grass pours directly into our precious streams and rivers.
Developers of land also look to this model for their land plans, causing much destruction of the soil and of vegetation since natural land and the native living soil profile are not valued for the turf grass and weed tree landscape paradigm. Soils are stripped and compacted to expedite "development" and a living system that took hundreds or thousands of years to develop is removed in site "improvements". Much of the living topsoil is stripped away and sold at a profit. The result is a sterile soil that needs tons of fertilizer to support a thin "rug" of turf grass, and weedy landscape trees that stunt in their development in saucers of compacted subsoil with a thin veneer of redistributed topsoil. Such a landscape cannot sustain itself, and is a net problem for the environment as a whole.
A holistic look at the landscape suggests that many areas do not require a turf grass treatment or weedy hybridized landscape trees and shrubs, rather it is a "default landscape" installed to "keep up with the Jones’" and to conform to social norms. Given the environmental and economic costs of the lawn and non-local plant life, it is time to re-evaluate priorities and reduce or eliminate the high-maintenance turf monoculture from areas not needed for "outdoor rooms", sport facilities, walking areas within parks, or safety/visibility. Remember, if we get rid of 50% of our lawns, and replace them with sustainable landscapes, we will eliminate nearly 300 million gallons annually of fossil fuel consumption. To put that into perspective, that is enough to propel a full passenger train 150 million miles (at two gallons of fuel per mile), or nearly enough energy to run all of Amtrak diesel passenger trains for nearly five years at an average annual train-miles of 30-37 million. Think of it, our energy that goes into lawn maintenance each year could power a national rail network five times larger than the current one that exists. Fortunately, there are sound alternatives that can replace the traditional turf-based and non-native landscape in many situations.
The ideal lawn replacement is the sustainable landscape. Sustainable landscapes utilize native or locally grown plant materials, long-lived and self-replicating plants, other locally obtained materials, and emphasize reduced labor and fossil fuel usage in installation and maintenance. Pockets of lawn can be retained to create visual cues to maintenance, to frame the landscape and to provide access. The new smaller turf areas can often be mowed using small electric or nonmotorized lawn mowers. Native plants such as buffalo grass and Pennsylvania sedge can provide the turf-grass look without the impact of traditional turf.
The least intensive and most sustainable landscape, once established, is the prairie, savanna or forested native plant community model that once dominated the Midwest or Northeast region, the native chaparral, montane forest or desert of the Southwest and Rocky Mountain states, the native grasslands of the Plains, the forests and Palouse prairies of the Pacific Northwest, or the pine woods and wetlands of the Southeast. Consult your local State department of Natural Resources or the Wild Ones to see which native plants are appropriate to your region and site. The cost savings of native prairie or other natural landscaping can be significant. Natural landscaping, when labor and energy costs are factored in, can save the residential or commercial landowner $2,000 to $3,000.00 per acre or more per year in maintenance costs and slash fossil fuel usage by 95 percent or more, according to my calculations and research by other sustainable landscape advocates (link- Conservation Design Forum). Installation or landscape retrofit costs for turf grasses can cost as much as four times that of a prairie seeding or twice that of a native prairie seeding and planting. This cost differential can increase greatly if sod is used rather than grass seed. The native landscape as an element in conservation development can save from $300.00 to $700.00 per acre in reduced installation costs due to avoided infrastructure costs and reductions in flood damage. Such conservation developments emphasize native plants as a highest and best use management landscape practice.
The water quality benefits of native plant communities can be seen at Prairie Crossing, a conservation development in Libertyville, Illinois, where storm water basins surrounded with native prairie and oak savanna support reproducing populations of three Illinois state-endangered fish species that require high water quality. Water is also treated in rain gardens and native vegetated swales before entering the storm water basins. This is in stark contrast to the eroding, algae-infested storm water basins typical of conventional developments. Recent studies in Wisconsin lake shore areas have found that storm water runoff events are nearly twice as frequent and runoff volumes 10 to 100 times greater in turf grass areas as they are in native woodland, and turf areas contribute 10 to 100 times the direct runoff or export of nitrogen and phosphorus to the lake as woodland habitat. Significantly, these studies also found that turf areas contribute three to four times the available nitrate and phosphate to ground water relative to natural areas, demonstrating that lawn impacts travel far beyond the specific turf location. All of these excess nutrients harm native lake plants and animals, and cause harmful effects such as algae blooms and loss of water clarity. Unlike turf, especially over the compacted soils in developed land, prairie and woodland habitats intercept and absorb rainfall and nutrients before they reach water features, and help serve as infiltration areas and recharge areas for groundwater. Research has documented that areas planted to switch grass, a native prairie grass, can absorb nearly seven inches of rainfall per hour, while a turf grass area in urban land absorbs less than one-third of an inch of rainfall in the same amount of time. The shallow roots of turf grass (less than 10 inches deep) function poorly for long term erosion control, especially on steep slopes, stream banks, and along other water features. The shallow roots of the grass in the above photo is in contrast to the deep root systems of native vegetation, which can reach down several feet for woody plants and up to 10-15 feet deep for native tall grass prairie plants. These can knit together stream banks and prevent problems such as that in the picture.
Recent research has also quantified benefits of native prairie and other natural areas with regard to sequestering carbon. Upon a doubling of atmospheric carbon, prairie is capable of storing an additional ½ ton per acre of carbon from the atmosphere per year above the current baseline of ¾ ton, and can store carbon at levels below 18 inches in the soil (link), unlike turf. Forested communities and savanna can sequester up to one ton of carbon per year per acre, and wetlands nearly one-half ton. Turf grass can sequester nearly a half-ton per acre, but that does not factor in the energy consumption and emissions from mowing, trimming, clean-up, fertilizing, providing water, and the energy consumed to manufacture, mobilize and maintain the lawn care equipment. When these factors are considered, a one-acre lawn in the upper Midwest, mowed/trimmed 25 times a year and maintained by the homeowner, consumes the fuel equivalent of 91 gallons of gasoline per acre and contributes a net yearly greenhouse gas output of 1,085 lbs of carbon dioxide after the carbon-sequestering of the grass is subtracted. Contracted commercial lawn care is even more greenhouse-gas intensive due to the need to provide transportation to the job site and increased wear and tear on lawn equipment. These numbers are from my own calculations and research. I have developed an annotated Excel spreadsheet that shows the assumptions and rationale behind these calculations – please send me a private message if you would like a copy of them.
The ideal turf grass lawn, by nature is maintained as a monoculture, and additional research has documented the unstable nature of monocultural plantings, that when disease, drought or other factors strike the only species present or only one of a few, nothing is there to replace it (link). Diverse native plantings also help control weeds The natural resources of the surrounding soil are also not used efficiently, leaving them available to leach into surrounding areas. The energy inputs for fertilizer, herbicides and pesticides required to maintain the monoculture is staggering. Research has found that the more species present in a plant association, the more resistant it is to invasion by weeds, and the more efficient it is in converting sunlight, oxygen, and nutrients to stored carbon in biomass (plant matter). A sixteen-species prairie creates nearly 2.9 times the biomass (weight of plant material) per unit area of a single-species monoculture (single species planting, like a lawn. The more carbon that is tied up in plant matter, the less that is available to be discharged to the atmosphere, thus helping reduce greenhouse gases.
Now that we know the benefits of native plants and other select in reducing and cleansing stormwater runoff, excess nutrients, and absorbing carbon dioxide, how can we apply them and their benefits to residential and commercial landscaping without appearing weedy or unkempt? A quick summary of planting practices and beneficial techniques is listed:
- Frame the native planting with small areas of turf, or hardscape such as pavers, stone edging or flagstone walkways to give the landscape a "cared-for" look. Avoid using the tallest native species in small areas to keep it
- Match appropriate native plants to moisture gradients, slope, shading etc. Hundreds of native species exist and can be matched to nearly any landscape situation in the Chicago region or any region in which one lives.
- Eliminate turf from basin banks, steep slopes, lake and pond shores, and other difficult to maintain areas. Replace with native plants.
- Replace unutilized turf areas with native plants, or other more sustainable landscaping emphasizing long lived trees, shrubs and perennial plants.
- Plant drifts of native plants to emphasize color and texture; plant a diverse mixture for seasonal color throughout the growing season and to resist weeds.
- Install native vegetation in infiltration strips, bioswales, small bioretention areas, rain gardens, and naturalized storm water shoreline plantings to mimic natural systems and to infiltrate runoff from roofs, pavement and lawn areas that remain. This will reduce the need for expensive end-of pipe stormwater infrastructure.
- Develop green roofs with native and select imported species to catch and absorb rainfall, and to reduce runoff effects and urban heating.
- Place rain gardens of emergent and wet-prairie plants at the end of downspouts, sump pump outlets, curb cuts and other small-scale storm water sources.
- Deep rip subsoil to 18 inches in compacted areas to promote deep rooting and stormwater infiltration. This is especially important in recently graded/constructed areas and urban developed areas built after the 1950s.
- Minimize grading in new development and preserve native soil profiles whenever possible. Avoid large scale mass grading through clustering of developed features.
- Install a minimum 35-foot wide buffer of native vegetation along waterbodies for effective filtration of runoff from paved areas and turf.
- Install cisterns (underground tanks) to collect and reuse rain water from impervious surfaces to reduce the need for groundwater and well water.
- Avoid using known invasive species in the landscape.
- Grow fruits and vegetables for home and local consumption. The new victory garden for sustainability.
Here are some examples of the beauty of sustainable landscapes
A small bed using local materials (stone) and native/non-invasive plants in a suburban setting
A constructed detention basin pond in a shopping center landscaped with native plants in the Chicago suburbs
A roadside with native prairie wildflowers and grasses in Wisconsin.
A woodland in a residential area after clearing buckthorn and reseeding with native wildflowers.
In conclusion, by replacing one-third to one half of existing turf with native plantings or sustainable landscaping, millions of gallons of fuel could be saved, millions of tons of greenhouse gases could be avoided while pulling millions of tons of carbon out of the atmosphere, water quality could be improved nationwide, and millions of dollars of scarce public and private monies could be saved in landscape maintenance and avoided stormwater infrastructure costs. Millions of dollars in annual direct cost savings can also benefit homeowners and businesses that switch to sustainable landscaping. Finally, in areas that can support it, landscapes should be put to work growing food, and home vegetable and fruit production should be part of any sustainable landscape. We have forgotten how to feed ourselves. That is a topic for another day and diary.
Resources and cited examples for further reading on sustainable landscapes, landscaping issues and the effect of our current landscaping practices on the land.
- Native biological swales and rain gardens –. The Prince George’s County, Maryland site provides technical and design information on these sustainable landscape techniques for the east coast and Midwest.
- Invasive species – Comprehensive source on weeds and non-native plants, as well as problem animals, and how to mitigate the effects of them. Economic damage from invasive species runs into the billions of dollars annually.
- The Wild Ones - Natural and native landscaping advocates, with a focus on homeowners and educational groups –. This organization provides excellent how-to advice and sharing of knowledge on native plants and natural landscaping, and is an advocate for repealing antiquated landscape laws that promote mowed turf landscapes at the expense of sustainable landscapes.
- Redesigning the American Lawn and a listing of other sustainable landscaping books and resources - - This list is a fairly comprehensive and the books contained here contain a more in-depth discussion than can be found in this diary.
- Designing landscapes with native plant communities - Excellent reference and detailed how-to on natural landscaping, with focus on the Midwest, Great Lakes Region and East Coast.
- How and why a typical residential house in an inner ring suburb Elmhurst, Illinois of Chicago, was retrofitted with sustainable landscapes – a success story: