Note: the following was written in February, 2018.
Last April, California’s governor declared, “The drought emergency is over,” but already, less than a year later, in the middle of a warm, dry winter, we are on the cusp of another such “emergency.” Perhaps we should find another word to utilize when yet another water shortage is upon us since, if you examine the climatological history of California, you find that drought is the rule, not the exception. Here, historically speaking, a wet winter is an aberration.
Scott Stine, professor of geography and environmental studies at Cal State East Bay, charted the history of California’s climate through examination of tree stumps in Mono Lake and other parts of the Sierra Nevada. Stine’s research revealed a startling truth: the last 100 years have been among the wettest in California history, going all the way back to 5000 B.C!
In other words, the snow and rain that we rely upon today to quench the thirst of 38 million Californians and to water our crops (California agriculture receives 80% of our water), has been much more plentiful during the last hundred years than we had any right, based on the complete historical record, to expect.
We call a drought “severe” if it lasts more than two or three years, yet there have been many droughts that lasted between 10 and 20 years during the last millennium or so, and two of those droughts were each approximately 200 years in length.
When it comes to our own little pieces of paradise — that is, our gardens — what are the implications of this ongoing droughty reality?
When coping with perennial drought, four strategies come into play: rain storage, water recycling, drip irrigation, and plant selection.
Where rainfall storage is concerned, place rain barrels, available at home centers, under your rain gutters to trap rainfall before it goes to waste. If your rain gutters go down to the ground, this means you will need to cut them off at the height of your barrels and direct the flow into your barrels by affixing properly positioned downspouts to the newly cut edges of your rain gutters. To apply for a rain barrel rebate, visit socalwatersmart.com. When you get there, click on “Residential Rebates” and then scroll down until you see a picture of a barrel. Click on the barrel and follow instructions. For a step by step guide to barrel installation, go to treepeople.org. When you get there, click the magnifying glass in the top right hand corner, and type in “rain barrel” in the search box.
On the Tree People facility at the intersection of Coldwater Canyon Boulevard and Mulholland Drive, there is a fascinating exhibit of water storage techniques, including a sloping driveway of the facility itself which collects and stores rain water that is then used for irrigation of the surrounding landscape during the dry season. Perhaps, in the future, all of our driveways will be appreciated for their rainwater collection potential and designed (or redesigned) accordingly.
As far as water recyling is concerned, water from the shower, bathtub, bathroom sink, and washing machine — collectively known as gray water – are appropriate for garden use. Currently, in the city of Los Angeles, re-using washing machine water does not require a permit as long as the recycled water enters your garden bed at least two inches below the soil line or two inches below a layer of mulch. Re-using gray water from the bathroom, on the other hand, will require a permit, albeit of the simple, over the City Hall counter variety. Kitchen water, however, whether from the sink or dishwasher, is inappropriate for garden use and should not be recycled for that purpose.
Drip irrigation, the salvation of water thrifty farmers and gardeners around the globe, was invented in Israel in 1959 by Simcha Blass. Blass, a hydraulic engineer, had first thought of the idea of drip irrigation when, in the 1930’s, a farmer showed him a tree that had reached an enormous height compared to surrounding trees, apparently without water. Blass proceeded to dig around the tree only to discover that a coupling from an irrigation pipe was showing a very tiny leak and yet, underneath it, a large onion shaped wet spot had developed to a significant depth. This barely dripping leak was clearly responsible for the outsize growth of the tree. Later, Blass would found Netafim, a major producer of drip irrigation tubing and its accessories. Today, Netafim products may be found in the plumbing supply department of every home center.
The advantages of drip irrigation go beyond water savings. Many insect pests and plant diseases — from scales to powdery mildew — proliferate on wet foliage and stems during spring and summer. By keeping foliage dry through the use of drip irrigation, where only roots come in contact with water, these pests and diseases cease to be a problem. Drip irrigation is also most effective at watering slopes since, aside from eliminating run-off associated with overhead sprinklers, drip applied water slowly seeps into the slope, allowing roots to take advantage of every drop of water that is leaked in their vicinity.
Last but not least, choice of plant species is also a strategy for coping with water shortages. California natives, as well as plants whose habitat is found among the lands bordering the Mediterranean Sea, in addition to plants native to southwest Australia, South Africa, and southwest South America, are most suitable where water conservation is concerned.
Tip of the Week: The National Garden Bureau (ngb.org) has come out with recommendations for a cutting garden. A cutting garden includes plants that stand up well in vase arrangements. The list features several dahlia varieties, as well as two sunflowers, one of which is white, a zinnia that could be mistaken for a dahlia, a lilac, fernleaf lavender (Lavandula multifida) with lacy,finely cut silvery foliage, a spectacular double pink poppy, a pink gerbera daisy, an old-fashioned highly fragrant rose known as ‘Sweet Mademoiselle,’ and finally, Utrecht blue wheat, whose blue seed heads maintain their cobalt blue color long after the other flowers in your bouquet have faded.