The Greener Gardening Idea: Drip Irrigation or Xeriscaping?
It's tough to calculate precisely how much water the average American puts on their landscape every day. Sizes of yards, systems for watering, and ecological locations all vary greatly. But reliable estimates each of us uses between 112 gallons to 180 gallons a day, and the EPA estimates 30% of a household's water use goes to watering the yard. While estimates are varied, there's one thing we can agree on: When water is scarce, pouring it on ornamental landscaping is wasteful. But there's another thing we can all agree on: Well-tended landscapes are pretty. How can we have our cake and eat it too? Two options come to mind - drip irrigation and xeriscaping. But which is the more eco-friendly solution?
Wasted water from sprinkler systems. Photo via roland via Flickr CC
Is Saving Water In the Garden That Important?
This is a pretty localized issue. In places with plenty of precipitation, the cheapest, greenest solution is clear - you barely have to water at all, anyway, so use the system you have as conservatively as possible. However, for more drought-prone places like California, Nevada and the Southwest, this is a question with big implications. No matter where we're located, interest in saving water is on the tips of everyone's tongue. And with yards being given 20-40% more water than they need, anyone tending a yard likely has room to improve. So what's the best way to go about doing it?
Drip irrigation line. Photo via photo farmer via Flickr CC
What Are Drip Irrigation and Xeriscaping?
What is drip irrigation?
Drip irrigation is essentially hoses with holes. A drip irrigation system consists or a series of small rubber tubes that run through your garden, usually hidden by mulch, with a dripper head poked into the tube at the location of each plant you'd like to water. When you turn the water on, the dripper head leaks small amounts of water only where you want it, making watering a very efficient process. They don't work for lawns or ground-cover areas, but then again, lawns don't work for water efficiency anyway.
Drip irrigation products include soaker hoses, dripper likes, and user-installed emitters. Soaker hoses are hoses that aren't water tight, and let water seep through its walls to dampen the ground it's laid on. They aren't that great of an idea, because they can't be easily customized for watering particular plants with particular amounts of water. Dripper lines have holes placed at uniform intervals. They're better than soaker hoses but still not ideal for really efficient watering. The best system for drip irrigation in a home's yard, is user-installed emitters. They take more time to install, but you can customize them to provide water exactly where you want it, in amounts that best suit each plant you're watering. They're also really easy to change up as you alter your landscaping.
Drip irrigation systems are very easy to hide, inexpensive to install, relatively easy to maintain, easy to customize and can save a lot of money and water in the long run.
What is xeriscaping?
Drought tolerant landscaping, or xeriscaping, consists of using plants that don't need much, or any, watering once established. The beauty of going with xeriscaping in drought-prone places is you can usually be even greener by selecting native species, which are adapted to the area's climate already. You can get a two-for-one in many areas by growing an herb garden with plants that are drought tolerant, like rosemary, lavender, sage, thyme and other varieties. Some gorgeous plants do well when starved of water, such as roses. After the first year or so when the plants are established, you won't need to water them at all, unless there is a severe drought or heat wave. Landscaping for drought tolerance can be done anywhere, not just in dry climates, and the popularity is growing as people realize the money it can save. Even lawns can be made more drought tolerant when the correct variety of grass is used. But most drought tolerant landscaping consists of native plants or plants known to need little water with decomposed granite (DG), rocks, or mulch as ground cover.
Homeowner associations can be a downer, though. For instance, Nearly 25 percent of California's homeowners live in developments that are governed by CC&Rs.; And, in many cases, residents of these developments can be fined by their association if they replace their existing landscaping with California-friendly plants. Not cool. In these cases, drip might be better, or taking an active role in your association and getting the CC&Rs; changed.
Xeriscaped yard. Photo via Jeremy Levine Design via Flickr CC
How Do Drip Irrigation and Drought Tolerant Landscaping Stand Up to Sprinklers?
Compared to a traditional sprinkler system, how much water does drip irrigation save for the average homeowner?
Yards and systems vary greatly, so specific dollar amounts are impractical to calculate. But what is known is the percentage of water that the system will save the average user. Compared to sprinkler systems, drip irrigation saves an average of 50% (depending on your yard's features, anywhere from 30-70%) of the water a homeowner will use on their yard. Much of this is through less frequent watering, since drip systems use water so much more efficiently, with none of it being wasted through wind, evaporation, and run-off. Drip irrigation provides water to specific places at a rate slow enough that it gets effectively absorbed into the ground.
A draw back for drip irrigation is that it doesn't work for large areas of lawn or ground cover, which many people want to keep. But for gardens, landscaping with shrubs and larger plants, flower beds, and container pots, it's an excellent alternative to sprinklers. Imagine being able to cut your yard water consumption in half, and what that will save you on your water bill, and drip starts to look mighty attractive.
Compared to a traditional sprinkler system, how much water doesxeriscaping save for the average homeowner?
Similar to drip irrigation, drought-tolerant landscaping can cut back on landscape water use by 50-75% With estimates that 50% of residential water use goes towards lawns and landscapes, having a landscape that requires as little water as possible makes a big dent in consumption. One potential water savings scenario to consider, as pointed out in the Handbook of Water Use and Conservation is to consider 1 inch of water applied over a 1,000 square foot long equates to 624 gallons of water, and if allied three times a week, that adds up to 97,344 gallons just to keep some grass green. Yikes!
Drought tolerant plants, on the other hand, require watering during their first year, but once established require watering maybe once a week during summer months, or not at all, depending on the plants you select. From 97,344 for a lawn, to nearly nothing in just a year or two...that's a serious savings.