A recent commenter here alerted me to Linda Chalker-Scott, a Ph.D. horticulture prof at Washington State U., director of their Master Gardener Program, and the primary hort authority behind Master Gardener Magazine. She’s known for her articles debunking Horticultural Myths, and who can resist a good debunking?
So like any long-time gardener, I breeze through the myth articles, feeling smug because I know better than to fall for them myself. And then she lays this one on me: "The use of drought-tolerant plants reduces water consumption," which she calls the Myth of Xeriscaping. WTF?
Here’s her point as best I understand it. Yes, drought-tolerant plants (like cacti and mesquites) can survive with less water, but in drought situations they drop leaves and slow their growth and thus are "less aesthetically pleasing". As a result, homeowners, even if they understand the importance of water conservation, crank up the irrigation so the plants will look better and wind up using more water than their neighbors with "traditional landscapes." So ironically, the more environmentally concerned homeowners end up using the most water. Linda’s prescription: We need to "develop a new philosophy," in which we accept the horrors of leaf shedding and reduced growth. OR, I’d suggest, ask for plants that still do well under drought conditions. Is that asking too much?
And there may be an actual university-sponsored study in Arizona that showed increased watering by homeowners of their xeriscape gardens but frankly, IT MAKES NO SENSE. Maybe the study subjects were check-writers, not gardeners. Any other ideas?
But the blame doesn’t just lie with profligate homeowners; it’s also the fault of those damn drought-tolerant plants. Research has shown that mesquites use more water than oaks under
optimal conditions. After all, it’s their very ability to take up and store water, camel-like, what makes them drought-tolerant. But if they take up water when it’s plentiful, what harm is done?
So let’s assume for the sake of argument that Linda’s point is well taken (because hey, she’s got the credentials). If drought-tolerant plants AREN’T best for water conservation, what plants are?? What about the non-succulent drought-tolerant plants, like daylilies, salvias, nandina or the rugosa rose? And is her point that we should avoid drought-tolerant plants or just get used to them looking crappy? Linda, please clarify.
Photo taken Thanksgiving of 2005 in Tucson, AZ.