For greener gardening, avoid the three 'Ps' in your backyard
A recent scientific study upset gardeners from the United States to Europe by declaring that urban agriculture has a carbon footprint that’s up to six times larger than that of commercial agriculture. What’s up with that?
Though the researchers did not investigate urban backyard food gardens, they found that single plots in community gardens can produce significant amounts of pollution from carbon emissions. Practices such as tilling and double digging are especially harmful, as they release soil-stored carbon and disturb soil dweller communities. Depleted of these natural helpers, soil is less able to support plants, which then require more artificial fertilizers. And the manufacturing and transporting of those is very carbon-costly.
The least harm and greatest benefits are created by organic growers and gardeners who regularly amend soil, use natural care products, and recycle materials. Soil building is an annual task that pays off generously, since plant health is strongly and positively affected by soil health. Compost mulches feed both soil and plants, while no-till and limited digging practices reduce soil disturbance, so plant-partnering soil-dwellers thrive. Where chemical fertilizers poison critters and waterways, benign organic fertilizers provide slow release nutrients that feed plants all season, improve soil texture and structure, and boost moisture-holding capacity. Reusing materials cuts down on carbon and energy costs of making and transporting many garden needs, from pots and flats to woven shade cloth and heat-holding covers. Reusing structures such as cold frames, trellises and plant supports similarly reduces both our gardening footprint and the waste stream.
The study also targeted three perilous substances that can make even a small garden do more harm than good. Pesticides, peat, and plastic are called out as damaging and unsustainable materials that don’t belong in a climate friendly garden or yard. Besides their energy and carbon burdens, pesticides have well documented side effects, from killing non-target critters to polluting air and every major waterway in the U.S. In contrast, natural care solutions support nature’s ability to control pests without chemical toxins. Peat harvesting destroys ancient bogs that are valuable habitat and carbon sinks yet peat moss adds no nutritional value to garden soil. Using beneficial soil conditioners such as farm manures and fine wood chips reduces water and air pollution while boosting soil quality. Other soil builders like compost, coconut fiber and rice hulls include recycled food byproducts that would otherwise be part of the waste cycle.
Plastics represent the dark underbelly of gardening: almost every plant we purchase comes in a plastic pot, most which end up as trash. Though some nurseries and growers accept clean, sorted pots that are gallon sized and larger, smaller pots are less welcome. They are rarely recyclable, since different kinds are made from various plastic resins that are not mutually compatible. What’s more, colored plastic is rarely recyclable: recycling facilities use light beams to sort plastics and darker colors get rejected as trash. Sadly, plastic is ubiquitous in the nursery business, from pots to plant tags to greenhouse covers and more, and most of it becomes trash.
On the flip side, plastic is also heavily used in commercial food production, transportation and marketing -- so whenever we grow and eat food at home, we ease that burden a little bit.
Our plant choices can also lower our carbon debt, particularly with crops that typically travel hundreds or thousands of miles to our local stores. Among the most carbon-costly crops are greenhouse grown tomatoes, so growing these organically at home is especially beneficial. Turning any excess into salsa and sauces to can or freeze makes that choice even more helpful. Commercially grown asparagus has a big carbon price tag, but Washington asparagus is famous, and once established, a backyard asparagus bed will be productive for years. Other crops that lower our carbon costs include peas and beans, both high in protein and easily dried and stored at home. Most root crops are relatively easy to grow and less prone to pests, so consider growing beets, carrots, garlic, onions, and potatoes too.
Onward, right?
Contact Ann Lovejoy at 413 Madrona Way NE, Bainbridge Island, WA 98110 or visit Ann’s blog at http://www.loghouseplants.com/blogs/greengardening/ and leave a question/comment.
This article originally appeared on Kitsap Sun: Three things gardeners should avoid to cut pollution
