One simple, cost-effective way to reduce your water use is to set up a greywater system that allows you to capture and redirect water from your washing machine for use on landscape trees, shrubs, ground covers, and lawn. (It should not be used on vegetable gardens where you are growing root crops or where edibles touch the ground.)
On average, a laundry-to-landscape system will recapture 17 gallons a day per person. For a family of four over one month, that amounts to a whopping 2,000 gallons for reuse.
Some counties offer rebate programs that cover all or part of the material costs for setting up a greywater system. The Santa Clara Valley Water District offers a Graywater Laundry to Landscape Rebate for properly connecting your washing machine to a greywater irrigation system. For most cities in the district the rebate is $200; some, such as Cupertino, are subsidizing the program and offering $400 per household.
According to Justin Burks, manager of the rebate program, “laundry to landscape greywater systems are simple, relative to other greywater systems. Most folks are able to set the system up over a long weekend or two.” But if you aren't all that handy, or just don't have the time, there are many trained professionals who can do the job for you. Installation prices range from around $700 to $1,000, including materials. A properly maintained system should last about 10 years.
Greywater can't be stored; it needs to be distributed to one or more areas that have been dug out, backfilled with mulch and are large enough to absorb the water. The mulch basin must be large enough to prevent runoff or pooling, and tubing needs to labeled appropriately so the water isn't used for drinking.
When you apply for the rebate, the water district will provide you with the square footage needed for a minimum mulch basin, based on your washer's age and type, the amount of laundry you do and the soil type on your property. In many areas, no permit is needed, but customers must verify that with their local planning or building department before starting the project.
No pre-inspection by the water district is necessary, but after installation, an inspector will visit to verify the system was set up and is performing properly. After passing the post-inspection, applicants will receive their rebate checks in four to six weeks.
When using the system, you will need to use biodegradable and non-toxic detergent (widely available) and avoid bleach, since it can be harmful to plants and soil. It's also best to avoid using greywater to irrigate acid-loving, pH-sensitive plants, such as blueberries, ferns, camellias, and rhododendrons.
“Recycling and reusing every drop of water that you possibly can not only saves you money, it's the right thing to do,” says Richard Santos, vice chair of the district's board of directors. “Using water wisely, especially on your landscape, is a win-win!”
But before you reach for that toolkit, go to the website valleywater.org to check out the rebate requirements and fill out the application. Wait to receive a Notice to Proceed before starting work.
Although a greywater system may not be at the top of your holiday wish list, it truly is a gift that will keep giving back — to you, your family and the planet!
by UC Master Gardener Rebecca Jepsen
This article first appeared in the December 10 print issue of the San Jose Mercury News.
Knowing soil types and water requirements may help us grow healthy vegetable gardens and flowers, but it is also vital when it comes to trees.
Igor Lacan, environmental horticulture adviser for UC Cooperative Extension, says as we move toward warmer temperatures with less predictable annual rainfall, we will need to make smart choices about our landscapes.
“Even in a drought, it is essential to prioritize your trees,” Lacan says. “Trees not only support our native birds, bees and wildlife, they provide major ecosystem services to us as well. Urban trees lower the ambient temperature, thereby reducing the need for air conditioning, sequester carbon from the atmosphere, provide stormwater capture, decrease pollution and enhance the property value and aesthetics of your home.”
Start with soil
In order to practice responsible irrigation — using enough water to keep a plant alive and no more — knowing your soil type really does matter.
Soil type, or texture, refers to the proportions of sand, silt and clay particles in its makeup. Sandy soils are coarse and drain quickly. Plants in sandy soil need frequent watering and may need fertilizer.
Clay particles are very fine and become glued together when wet, and although clay soil can be slow to drain, it retains moisture and minerals, requiring little to no fertilizers.
The roots of newly planted plants may have a harder time getting started if the soil is hard and dense, but once established, plants tend to thrive in clay soils.
Silty soil is found along our riverbeds, lakes and other riparian areas. Particles are smaller than sand but not as fine as clay. It drains well and has good nutrient retention.
Loam represents a combination of sand, silt and clay and most of the Bay Area has clay or loam soil.
To tell what kind of soil you have, moisten a handful of it and give it a firm squeeze. If it holds its shape but crumbles when you give it a poke, you have loam. If it holds its shape without crumbling, you have clay. If it falls apart as soon as you open your hand, you have sandy soil.
Knowing your soil type will guide you in how much water to apply and how often.
To gage soil moisture levels, you will need to dig down to the root level. For trees, use a shovel or an auger to get 12-18 inches below the surface. After watering to this depth, soil should be moist but not drenched.
For mature trees, deep water infrequently, about once a month. Imagine refilling a 12- to 18-inch deep water reservoir around the tree's roots.
It's important to water beneath the entire canopy. Installing a Tree Ring Irrigation Contraption (TRIC) is a great way to accomplish this.
Newly planted trees may need only 10-15 gallons per week, but they may need additional water in extremely hot weather.
In all cases, a good rule of thumb is to water deeply and observe your tree. If the tips of the leaves and branches start to droop, it's time to water again.
You will then be able to properly set up your automated irrigations systems. But remember, they need to be changed seasonally as the weather and temperature fluctuate. Online watering calculators can also be helpful.