Beautiful, plant-filled landscapes require water, but we live in the driest state in the nation. Western Nevada receives less than 7 inches of precipitation per year, and some years considerably less. But, we still want the aesthetic and cooling benefits of plants in our yard. What is a Nevada gardener to do?
An approach to water-efficient landscaping that is gaining a lot of traction nationwide is called the watershed approach. This approach involves making the best use of our natural precipitation by using a variety of techniques to hold the water on our landscape for plants to use. The benefits are that plants require less irrigation water to thrive, and we save money on the water bill.
In areas of the West that also tend to flood, like Nevada, an effective watershed technique is to work with the topography of your landscape in a way that captures and redirects rainwater to planted areas. This involves careful grading of your land to direct water from precipitation and irrigation runoff to trees, shrubs and bedding plants.
This approach has benefits beyond simply saving water. Holding landscape water in place promotes deep rooting of trees and shrubs, which helps them use water more efficiently. It also filters water as it moves through the landscape to remove many toxins and contaminants that may otherwise enter our river system.
To do this in a way that is beneficial to your plants, you also need to group your landscape plants according to their water needs. Water can then be redirected to areas with plants that have the greatest need. And, it doesn’t take a huge change in contouring to move water. A slight change in the angle of the soil can direct water in a new direction toward water-hungry plants.
A good place to start is by watching the movement of water on your landscape during a rainstorm. Pay attention to how the water flows, where it pools and where it runs off. Then, you can make subtle changes in grade to redirect the water or hold it in place for your plants. In most cases, this doesn’t require large equipment or a lot of money to accomplish. Most homeowners can make simple changes with a pair of strong gloves and a shovel.
Another thing you can do to keep water on your land is to improve the water holding capacity and permeability of your soil by regular additions of compost and organic mulches. If you have a lawn, make sure to core aerate once or twice per year, in spring and fall. This process pulls small cores of soil from the lawn, relieving compaction and improving water infiltration into the soil.
Plant selection is an important element of the watershed landscaping approach. Choose plants that are either native or regionally adapted. Your local nursery can be a good source of information and appropriate plants.
Plants that tolerate and thrive in wetter soils include gaura, heuchera and candytuft (Iberis). Plants that work in drier parts of your yard include blanketflower (Gaillardia), evening-primrose (Oenothera) and blue flax (Linum). Plants that can stabilize slopes on your landscape include yarrow (Achillea), bearberry (Arcostaphylos) and Oregon-grape (Mahonia).
For more information on grouping plants according to their water needs (hydozoning), find a copy of the book, Water-Efficient Landscaping in the Intermountain West. It can be found in some local libraries or purchased at the Washoe County Cooperative Extension office at 4955 Energy Way.
Heidi Kratsch is the northern area horticulture specialist for University of Nevada Cooperative Extension. Have a question about plant selection? Contact a master gardener at 775-784-0265 or firstname.lastname@example.org.