Tips on how to garden sustainablyBumble bees perform an invaluable function by pollinating flowers, such as this watermelon flower. Credit: Ivan Varlamoff
By Guest Columnist SUSAN VARLAMOFF, the former director of the University of Georgia’s Office of Environmental Sciences in the College of Agricultural and Environmental Sciences and lifetime Master Gardener
Landscapes occupy vast swaths of land across urban and suburban areas in the U.S. and how we cultivate our gardens directly affects the surrounding environment. Since Atlanta is bisected by the Chattahoochee River, which serves as a drinking water source, runoff from the land directly impacts the river’s water quality. Misuse or overuse of fertilizers and pesticides can result in water contamination as these chemicals run off the land during rain events.
In fact, a 1994 study revealed that Georgia’s urban watersheds were more contaminated with pesticides than rural watersheds where farmers cultivate their crops. Farmers are liable for any water pollution they may cause. Professional pesticide applicators are required by law to be certified through the University of Georgia to apply pesticides. But there was no training program for homeowners.
An EPA grant awarded to the University of Georgia Extension resulted in the development of Best Management Practices for home gardeners to reduce nonpoint source pollution. A survey of Georgia home gardeners revealed that nearly 70 percent wanted to garden to protect the environment.
Materials produced by the Georgia Cooperative Extension were reproduced by the thousands and workshops were standing-room-only events, even on snowy evenings before snow plows made it south. Concerns for the environment – climate change, biodiversity loss, water shortages, declining pollinators, invasive non-native species, loss of wildlife habitat – are mounting.
Just as we recycle, purchase fuel-efficient cars, and turn down the thermostats in winter to reduce our environmental footprint, we can also manage our landscapes to enhance the local ecology.
Since gardening is Americans’ No. 1 hobby, gardeners can transform neighborhoods and enhance depleted wildlife corridors in metro areas such as Atlanta by using science-based practices.
Gardening to restore natural systems is not as daunting as it may sound. By first recognizing that Mother Nature is our life support system, and that by mimicking her in our back and front yards, we can let her do the heavy lifting. Pollination, waste management, water and air purification, temperature modification, food and shelter are just a few essential services she provides that we can’t live without.
We can create a landscape that will be the envy of our neighbors, and also benefit the local ecology, by following these basic principles and practices.
The foundation of a healthy landscape begins with fertile soil. In some parts of the country, such as the Northeast, Northwest and upper Midwest, soils are rich in organic matter and nutrients. Plants thrive in these soils. In the Southeast, clay and sand are dominant soil types where fewer plants can flourish.
However, generous amounts of compost mixed into the soil will provide the nutrients and structure most plants require. Compost can easily be made in your backyard by piling yard and kitchen waste in a heap, and turning it from time to time. After six months, gardeners’ black gold can be used to enrich poor soils.
By grouping plants according to water needs, gardeners can save time watering plants and, most importantly, reduce the use of this precious resource by 50 percent. Most of the landscape (60 percent) should be planted in shrubs and trees, which require little watering beyond what nature provides. No more than 30 percent should consist of perennial beds and grass, which require occasional watering. Areas such as annual beds and containers should not exceed 10 percent of the landscape since they need frequent watering – sometimes every day. Rather than using potable water to irrigate annuals and perennials, collect rain water in barrels positioned under gutters to use for this purpose.
University of Georgia experts recommend that lawns should be no more than 40 percent of the total landscape. Why? Because gasoline powered lawn mowers release greenhouse gas emissions that contributes to global warming and garden chemicals, if improperly applied, can pollute streams and rivers. In metro Atlanta, homeowner outdoor water use in summer often doubles due to lawn irrigation. Lawns also are only one species of plant and provide no habitat for wildlife.
University of Delaware scientist Doug Tallamy has spent years researching the importance of planting a diversity of native plants and trees to attract local wildlife. Together they create a food web of interactions where each organism performs a vital function in the ecosystem. Non-native plants are not recognized by the local wildlife as sources of food so a landscape consisting of primarily non-native plants is an ecological dead zone. The Georgia Native Plant Society will furnish a list of indigenous plants. With this in mind, use native plants in your landscape to give Mother Nature a boost.
To make the ultimate ecological statement in your yard, plant a native oak tree. According to Tallamy’s studies, native oaks are nature’s biggest biodiversity attractors. In addition, they store carbon dioxide and reduce climate change, hold the soil to prevent erosion, cool the air and collect and filter stormwater. The American Forestry Association says that if every American planted just one tree, the amount of C02 in the atmosphere would be reduced by 1 billion pounds annually.
In addition to restoring ecosystems, gardening is great exercise, a way to meet your neighbors and commune with nature. Skip the gym membership and get started!
Note to readers: Adapted from Sustainable Gardening for the Southeast by Susan Varlamoff. Available at Barnes and Nobles, Amazon.com and University Press of Florida upf.com.