| Volume 12 | No. 3 | Summer 2010 |
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The Climate-Friendly Gardener |
The 81 million U.S. homeowners with a lawn or garden know that even small shifts in weather can affect their outdoor plans. Unchecked global warming, however, could force gardeners to deal with more droughts and floods, and a profusion of pests and weeds. A new UCS publication, The Climate-Friendly Gardener: A Guide to Combating Global Warming from the Ground Up, shows you how to reduce the impact of climate change in your own backyard, using the following science-based tips.
Tip #1: Choose low-emission garden products and practices
Gasoline-powered garden tools are major emitters of carbon dioxide (CO2), the primary global warming gas. The average gasoline-powered lawn mower, for example, puts 20 pounds of CO2 in the atmosphere for every gallon of gas it burns. But emissions can also come from unexpected sources such as synthetic fertilizers and pesticides; both require enormous amounts of energy to produce and transport.
Reduce your impact by using electric or push mowers, rakes, and other low- or no-emission lawn tools and replacing chemicals with compost and natural pest-control methods. Also, avoid potting mixes containing peat, since mining peat bogs destroys these ecosystems and releases large amounts of carbon stored there.
Tip #2: Don't leave garden soil naked
Stabilize, build, and add nutrients to garden soil that would otherwise remain bare in the winter by planting cover crops such as grasses, cereal grains, or legumes. Planted in the fall, they protect soil from weeds and erosion, and add carbon to the soil when they are turned under in the spring. Peas, beans, clovers, and other legumes also act as natural fertilizer by converting nitrogen from the atmosphere into forms that can be used by spring plants.
Tip #3: Plant trees and shrubs
Because of their size and long life span, trees and large shrubs remove more heat-trapping CO2 from the atmosphere than other plants. As an added bonus, well-placed trees offer summer shade and protection from winter winds, reducing emissions associated with home heating and air conditioning.
Tip #4: Recycle yard and food waste
Organic waste decomposing in oxygen-poor landfills generates methane, a heat-trapping gas 23 times more potent than CO2. By contrast, composting this waste in the presence of oxygen minimizes methane production. Composting also produces a nutrient-rich soil amendment that reduces the need for synthetic fertilizer while helping soil store more carbon.
Tip #5: Make your grass "greener"
Grass, like any green plant, absorbs carbon from the atmosphere, but some studies suggest that this climate benefit may be undercut by heat-trapping nitrous oxide emissions related to fertilizer use and generous watering. While there is no scientific consensus yet on the climate impact of lawns, you can make yours as climate-friendly as possible by choosing drought-tolerant species, mowing to a height of three inches or higher (which promotes deep roots), watering during the coolest part of the day (to minimize evaporation), and leaving grass clippings on your lawn (which returns nutrients and additional carbon to the soil and decreases the need for additional fertilizer).
Gardening practices alone won't solve global warming—reducing emissions from agricultural land, parks, and other green spaces can have a much bigger impact—but cultivating a climate-friendly garden or lawn is a step in the right direction. To learn more or download the full guide, visit the UCS website at www.ucsusa.org/gardenguide.
Also in this issue of Earthwise:
How can a consumer know which hybrid vehicle delivers the best benefits?
