In recent columns, I have addressed soil health as an emerging issue in global climate change, and described ways in which residential gardeners could participate in solutions to this high-level priority. The most important strategies for home gardeners in this connection include using mulches and cover crops to protect the soil from the elements; avoiding uses of synthetic chemicals, which attack the soil microbiome, and favoring regionally appropriate plants, including (for the Monterey Bay area) plants that are native to California and other dry-summer climate regions.
Today’s column focuses on uses of gasoline-powered garden equipment: leaf blowers, lawnmowers, lawn edgers and chain saws.
This equipment contributes to climate change and air pollution. The typical device uses a two-stroke engine, which, by design, does not burn the fuel efficiently, and instead emits large quantities of carbon monoxide, nitrous oxides and hydrocarbons. These emissions contribute to smog formation, climate change and acid rain, and hydrocarbons in particular can be carcinogenic.
Small trucks and passenger cars also produce worrisome emissions, but gasoline-powered garden equipment emit them at much greater rates. For example, leaf blowers produce 100 to 300 times as many hydrocarbons as does a small truck or passenger vehicle. Garden equipment with four-stroke engines perform significantly better, but still far worse than car engines.
In terms of environmental pollution, these are very dirty devices.
The California Air Resources Board has stated, “Potential health effects from exhaust emissions, fugitive dust, and noise range from mild to serious.”
Fugitive dust includes organic debris and “particulate matter,” which can include a variety of potentially nasty organic and chemical stuff that people should not breathe.
Noise pollution effects include annoyance, hearing loss (particularly by equipment operators), and a range of psychological impacts.
For more information, visit the website of Zero Air Pollution (www.zapla.org). This southern California organization details the range of health hazards associated with this garden equipment, wherever it is used.
Leaf blowers sometimes are used to clear organic materials, and leave bare soil. Making nature “tidy” in this way exposes the soil to the damaging effects of the sun and wind. The regeneration of healthy soil requires maintaining cover of vegetation or mulch materials.
Here are recommendations for ecologically appropriate uses of garden equipment.
- Minimize or eliminate the use of gasoline-powered devices in favor of manual equipment. Use rakes and brooms to clear leaves, a push lawnmower to cut grass, a long-handled edger to trim lawns, and a handsaw to prune limbs. These tools are consistent with a contemplative approach to gardening, and provide desirable exercise.
- When the task requires too much time and effort for manual equipment, use electrical devices. Battery technology is advancing to enable longer operation of small garden equipment; corded devices, although cumbersome, work quite well. (My corded leaf blower moves leaves nicely.)
- Negotiate with your “mow, blow & go” garden maintenance contractor to use manual equipment whenever possible. This might require a small rate increase, but everyone will be better for the effort.