For nearly 12,000 years, humans have been cultivating plants to feed themselves. The concept of rearing plants for visual rewards is much more recent, the earliest records of garden design were made only 3500 years ago. Since that time people have continued to advance this craft, growing beautiful exotic plants far from their natural habitats, hybridizing new forms not found in nature, miniaturizing trees in trays as bonsai, and developing chemicals to enhance plant growth. Our gardens are gorgeous, but can they hurt the health of our planet? Or help it?
Ten years ago, people argued about “the debate on global warming”. Today we discuss the effects of global heating, as scientific studies have resolved most of the debate. Humans now face ominous climatological and ecological problems of our own creation. Our fantastic technology has enabled us to make dramatic changes on the face of our world, but this change is not without repercussion.
But what does this threat have to do with gardening? Plenty.
In every aspect of our lives, we now must be aware of our impact on the planet. Because of our wealthy lifestyles (relative to most other nations), Americans have a disproportionately large impact. American gardeners are no exception, and we need to examine our activities and consider how they affect our world. Are we introducing ecologically harmful plants or pests? Is our yard equipment polluting the air? Are our fertilizers and chemicals running off into storm drains and other waterways? Does our tree-less landscape contribute to a heat-island effect? Was our mulch made from a tree harvested in the wild? Do the plants we choose consume copious amounts of precious fresh water? Not all gardening is “green”, or good for our environment.
The good news is that our 3500 years of horticultural prowess can be put to good use. As gardening stewards, we can choose alternative methods to lessen our “footprint”. Yes, this will mean making some changes in our garden designs, the materials we select, and the way we maintain our gardens, but this change is absolutely necessary. And I think once we get used to it, will become standard practice and second nature.
While some of our human ingenuity has resulted in ecological damage, it is now being used to create innovative solutions. One such solution is green roofs and green walls. Frameworks are created to hold a substrate against a building that can be planted with a carpet of durable plants. If designed well, they can be quite beautiful, and enhance their surroundings considerably. But more importantly, they can reduce energy used for cooling, slow rain runoff that can pollute waterways, and reduce heat gain. On a sunny day, put your hand on a plant in your yard, then on your roof. Which is hotter? Heat rising from bare roofs and pavement in an urban environment can not only make a city hot, but it can alter wind and rainfall patterns. Green roofs and walls significantly reduce this effect, produce oxygen, and provide wildlife habitat as well! A butterfly garden for your roof perhaps?
Another emerging horticultural technology is synthetic floating islands. Florida is covered with borrow-pits and man-made lakes that become reservoirs for runoff from fertilized turf and landscapes. These excess nutrients can create unhealthy (and sometimes completely barren) aquatic ecosystems. Floating islands are made from recycled plastic, the finished material looks like a gigantic “green scrubby” you would scrub pots and pans with. Its porous structure means it has thousands of square feet of surface area suspended in the water, which provides a home for beneficial bacterial and microorganisms that break down nutrients. To add to this effect, these islands are designed to hold a layer of soil that can be planted with a wide variety of ornamental plants. Essentially growing hydroponically, these plants extend their roots down through the island and into the water (like those coleus cuttings you rooted in a glass on your windowsill), and consume nutrients directly from the polluted water. You could even grow strawberries or vegetables! These artificial islands help to make the lake healthy again, provide nesting habitat, and beautify the pond. Now that’s thinking!
And thinking is what all need to do regarding our own gardening practices. Continue to learn about earth-sensitive gardening, and about the latest alternative methods. Of course, this awareness of our actions transcends gardening, as we strive to examine the many facets of our daily lives: how much energy we consume, the food we eat, and the products we purchase.
Continue to enjoy the rewarding pastime of gardening, but remember to do it not only for your own pleasure, but garden also with the Earth in mind.
“There are no passengers on Spaceship Earth. We are all crew.”
Marshall McLuhan, 1964
Florida Yards & Neighborhoods
University of Florida / IFAS Extension
U.S. Environmental Protection Agency
Mid-Atlantic Region Green Landscaping
Green Roofs and Walls
Green Roofs for Healthy Cities
Toronto, ON, Canada
Penn State Center for Green Roof Research
University Park, PA
The International Green Roof Association
Sustainable Ecosystems FTP
Floating Island International