Thomas Christopher | Be-A-Better-Gardener: Your lawn really doesn't need to be watered
In my hometown, drinking water is cheaper than dirt — quite literally. A cubic yard of water (201.96 gallons) costs me just 79 cents. That price includes the cost of pumping the water from the aquifer, testing it for purity, chlorinating it, and delivering it to my house via the municipal pipes. A cubic yard of topsoil, by contrast, costs $29 from the local supplier, and that's if I pick it up with my truck. What's more, because there is no legal definition of topsoil, I have no guarantees about what I'll be getting.
Why do I raise this point? Because it explains to a large extent the way we squander what is arguably our most essential resource, fresh water. If, for instance, I were to follow the example of some of my neighbors, and water my lawn during summer droughts as recommended by turf maintenance experts, administering an inch of water each week, I'd use about 454 cubic feet on my eighth of an acre per watering. That's just a hair over 3,394 gallons (17 cubic yards) — of drinking water. And I wouldn't think twice. But would I as thoughtlessly spread 17 cubic yards of topsoil over my yard? Certainly not. If nothing else, the $493 weekly price tag (plus delivery charges) would catch my attention.
The Environmental Protection Agency estimates that homeowners use, on average, 30 percent of their water from the municipal sources on landscape irrigation. That's a lot of water, roughly 8.22 billion gallons a day. And although the United States has, relatively speaking, a lavish supply of fresh water, we can't afford to waste any —a survey by the United States Government Accountability Office in 2014 found that 40 states (including Massachusetts and New York) reported at least local problems with water supply shortages. Those who draw water from their own wells (as I do during weekend gardening in the Berkshires) should remember that they are drawing on the same general supply and that self-sufficiency should not translate into selfishness.
Climate change, which is already inflicting hotter, drought-burdened summers on our part of the country, will only exacerbate this situation. However, there are things we can do. We can stop watering our lawns, letting the turf go dormant in summertime. We can install drip irrigation systems in our gardens. They apply water so much more efficiently that we can have the same impact with roughly half the amount of water. We can replace automatic irrigation controllers with simpler devices that have to be triggered by hand every time we want to irrigate, so that watering, rather than a default, becomes a conscious decision. That will put an end to the too-common sight of sprinkler systems watering lawns during rain storms. We can do something as simple as tucking our plants in with an organic mulch to reduce the moisture lost from the soil by evaporation off of its surface
What's more, our gardens will benefit from more accurate and sparing irrigation. Drip irrigation, for example, by applying water directly to the roots of selected plants spreads no moisture to the spaces in between, leaving less to promote weed growth and all the annoyance and problems that brings. Wetting plant foliage less often will reduce the incidence of foliar diseases. Giving plants just enough water favors compact, sturdier growth that is less attractive to deer and insect pests than the soft growth promoted by too-generous watering. The organic mulches we apply will, as they decompose, boost the humus content of our soil.
As every school child learns, almost two-thirds of a human body is water. With plants, the content is even higher: 95 percent of the mass of most annual and perennial flowers is water and even a seemingly solid Douglas fir is 85 percent water. Water, clearly, is our most fundamental resource in and out of the garden, and we must use it wisely.
Be-a-Better-Gardener is a community service of Berkshire Botanical Garden, located in Stockbridge, Mass. Thomas Christopher is the co-author of "Garden Revolution" (Timber press, 2016) and is a volunteer at Berkshire Botanical Garden. berkshirebotanical.org.
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