The Field

by David Hopman, ASLA, PLA

One of the best parts of my morning routine is to take a brisk-paced walk with my wife through our leafy suburban neighborhood in Arlington, Texas. It is a great chance to catch up on events, enjoy the changeable weather patterns in North Texas, greet and (occasionally) get caught up with our neighbors, enjoy the mature vegetation, and get the blood moving before a busy day. The neighborhood has very low non-arterial traffic flow that allows people and cars to comfortably coexist on the asphalt streets that are without sidewalks. However, at several points along our route, it invariably happens—the rise of the machines! Our morning reverie is interrupted with deafening sounds and billows of pollution and dust from gasoline-powered lawn and garden equipment (GPLGE).

These “machines in the garden” are ever with us, as was recently confirmed by a visit to Bloedel Reserve on Bainbridge Island near Seattle. Bloedel is one of my favorite places to return to and I always take the opportunity when I am in Seattle. Unfortunately, my aesthetic reverie at Bloedel was impacted by power equipment during my visit this summer and then became one of the incitements for this post.

As landscape architects, we are often responsible for designing the landscapes that are maintained by these environmentally and aesthetically abusive machines. Many people have written over the years about lower-maintenance alternatives to lawns and hedges, but adoption has been painfully slow. There is also surprisingly little emphasis on the effects of GPLGE on environmental quality by ASLA and by regulators. In Texas, the primary regulator for emissions is The Texas Commission on Environmental Quality (TCEQ). Their website has many suggestions for improving air and water quality. Drilling down to Voluntary Tips for Citizens and Businesses to improve air quality will eventually lead to a webpage devoted to lawn and garden care. On this page there are tips for harvesting and saving water, organic gardening, native plants, using trees to save energy, using less pesticides and herbicides, etc. GPLGE is very conspicuously absent.

One way to think about the air and noise effects of these small gasoline-powered engines is to compare them to average car exhaust. Running a typical leaf blower engine for one hour can produce similar levels of pollution as driving 11 new cars for that same hour. Considering that yard crews often have two or three engines running at once (trimmers, blowers, and mowers, for example), this could be like having 22-33 parked cars with their engines racing parked around your house or business! The chart below compares the best-selling leaf blower and lawn mower to driving a 2017 Toyota Camry, the best-selling car in the U.S. in 2017.

Multiplying these effects over the course of a day and throughout a neighborhood illustrates why many people are expressing concern for the long-term effects on human health. The EPA estimates that in 2018, there were 136 million pieces of gas-powered lawn and yard equipment spread throughout the United States.

There has been a push in the United States since the mid-1990s to begin the long and slow process of improving the environmental performance of GPLGE. However, according to the EPA, in 2011 approximately 26.7 million tons of pollutants were still being emitted by lawn and garden equipment, accounting for 24%-45% of all nonroad gasoline emissions (See Jamie L. Banks’ National Emissions from Lawn and Garden Equipment). Gasoline-powered landscape maintenance equipment (GPLME; leaf blowers/vacuums, and trimmers, edgers, brush cutters) accounted for 43% of Volatile Organic Compounds (VOCs) and around 50% of the dangerous fine particulate matter (according to National Emissions from Lawn and Garden Equipment, Volatile organic compounds = 461,800 tons; Carbon Monoxide = 5,793,200 tons; Nitrogen Oxides = 68,500 tons, Particulate Matter = 20,700 tons; Carbon Dioxide = 20,382,400). According to Michael Benjamin, division chief at the California Air Resources Board, there will be more pollution in California from gas-powered gardening equipment by 2020 than from cars.

Extensive evidence continues to mount on the adverse health effects of exhaust pollution and other fine particulates from gasoline-powered lawn and yard equipment. Cardiovascular disease, stroke, respiratory disease, cancer, neurological conditions, premature death, and effects on prenatal development have been documented (National Emissions from Lawn and Garden Equipment, page 2). It is strange that we still accept as a societal norm the running of high pollution machines, such as leaf blowers, near air intake vents for office buildings and around other areas where people congregate outdoors. The adverse effects are particularly severe for the operators of the equipment who breath the exhaust on a regular basis.

Sound is another issue surrounding GPLGE that affects both the use and enjoyment of outdoor spaces and our long-term ability to hear. The National Institutes of Health (NIH) equates the sound of a gasoline lawnmower (80-100 decibels) to the sound of a loud motorcycle and warns that both can cause hearing loss with sustained exposure. Leaf blowers are even louder, especially to the operator, where they average 95-115 decibels which is about as loud as a rock concert!

Returning to our morning walk, we occasionally turn a corner and are surprised by seeing, but not hearing, someone mowing the lawn. There is no hint of fumes and the sound of the mower only appears once we are two or three houses away. We are always pleased to discover that the person is using an electric lawnmower or other electric yard equipment. The sound level of an electric lawnmower has been compared to that of a typical washing machine, at around 75 decibels (see Quiet Lawns for a noise level comparison of gas and electric mowers). Electricity powered yard equipment also has a very low carbon and other pollution footprint, especially if you opt for 100% renewable power, as we do.

Until recently, battery electric yard equipment was very underpowered, and the only viable electric solution was to use corded equipment. This was very inconvenient and could even be dangerous as I found out when I cut the power cord to my electric hedge trimmer a few years ago. Fortunately, there are very highly rated battery alternatives available now with much better power and much longer battery life. The system I use allows me to share the batteries among devices. This makes the equipment much more affordable since the battery and charger can be the most expensive component. It also provides a backup in case the battery normally used for a piece of equipment runs out of power. I currently have a 56-volt system with one 2 amp-hour battery that I usually use for the line trimmer, the leaf blower, and the hedge trimmer. The mower uses a 5 amp-hour battery which keeps it going for about 50 minutes. All the batteries work on all the equipment and recharge in less than an hour (see photo below).

I have been using this setup a few years now and strongly encourage anyone looking for new lawn equipment for their home or business to seriously consider this neighbor- and environmentally-friendly alternative. I also encourage you to recommend lawn care companies that use electric equipment to your clients. Manufacturers are now producing very large backpack batteries of 28 amp-hours that are suitable for commercial companies and professional grade equipment (see Consumer Reports for recommendations on battery powered equipment from a variety of manufacturers). The lawn care companies will respond to customers. Imagine the relief of their employees if they no longer have to breath fumes and be exposed to the thunderous sounds of gas-powered equipment all day!

As landscape architects, we strive to create environmentally, ecologically, and aesthetically successful places. These places are then often severely degraded by maintenance practices using gasoline-powered lawn and garden equipment. I hope you will consider joining the fight to create places with cleaner air, lower carbon emissions, less noise, and healthier people by encouraging the switch to battery-powered electric yard equipment.

David Hopman, ASLA, PLA, is an Associate Professor of Landscape Architecture at The University of Texas at Arlington, a registered landscape architect, and a research associate at The Botanical Research Institute of Texas (BRIT). He is also an officer and past co-chair of the ASLA Planting Design Professional Practice Network (PPN).