By Heather Whitney-Williams, Boulder County Master Gardener
So, you are interested in xeric gardening — welcome! This is the beginning of an ongoing series to introduce beautiful xeric plants and their immense benefits to Colorado gardens, their gardening quirks, and the philosophy behind the xeric gardening movement in western states.
What does “xeric” mean? “A habitat containing little moisture; very dry.” Xeric plants need a fraction of the water that other plants need, and that is because they evolved in the arid West and other arid climates around the world. Denver Water coined the term “xeric plants” in 1981 to classify plant species that evolved with drought; it also coined the term “xeriscaping,” which is landscaping, or gardening, that reduces the need for supplemental water from irrigation. Other industry terms are “water-conserving,” “drought-tolerant,” “drought-resistant,” and “smart-scaping.” The emphasis is placed on local indigenous plants rather than imported “thirsty” plants, and planting zone and microclimate are important factors in plant placement.
Why is xeric gardening becoming such a “hot” gardening trend in the West? It is probably a confluence of factors, most notably increasing temperatures from global warming, economic instability, and the steady migration of people to arid western states. All of these in tandem put pressure on our water supply. Water use has been front and center in Colorado since the 1860s due to very important water law principles called Prior Appropriation and the Colorado Doctrine. These distinguished the western water law framework from eastern Riparian Law, found in wetter climates east of the one-hundredth meridian. In short, in the West, including Colorado, water must be for a beneficial use by public agencies, private persons, and entities as a portion of the public’s water supply, and the water can be diverted or extracted to transport and use. The law gets much more complicated, but the gist is that water is in such short supply that the “first in time, first in right,” or the early bird gets the worm, so to speak.
It follows that in arid Colorado, water isn’t limitless. It isn’t beyond the realm of possibility that the Front Range will eventually have to ration water, as the population is expected to increase by over a million people in the next 20 years. Since it takes roughly 80-100 bathtubs of water to irrigate an average lawn once a week, and over 50 percent of the Front Range water supply is used to irrigate lawns, we have to start thinking of ways to conserve our water. Gardening and landscaping with xeric plants is a start.