Scant Rain Means It’s Time to Water
About a month ago, on the shortest, darkest day of the year, I found myself puttering around the garden in short sleeves, wearing flip-flops and wondering, “Whatever happened to winter?”
There it was--the middle of our rainy season--and I was still having to water the garden, dragging a hose and sprinkler from bed to bed.
The rain gauge on my back fence was bone dry--any moisture from previous drizzles had evaporated in the dry air by the following morning.
It’s now nearly a month later and the situation has hardly changed. Up until this week, any rain was not enough to make a difference in the garden because it often didn’t even wet the ground under trees. Tuesday’s “storm” may have been the first real rain of the season--with about half an inch of precipitation--but the season’s total remains less than 1 1/2 inches, compared with the norm of more than 7 inches for this time of year.
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Climatologists are suggesting that the lack of rain might not be simply a short-term La Nina event, but the beginning of a decades-long dry spell for Southern California that would end a wet cycle that began in the 1970s. If true, we’ll have more of these dry winters in the future. We may need to think more about watering the garden during the “rainy season.”
According to water officials, we’re not headed for a drought quite yet, since our supply comes from afar and is not dependent on local rainfall (other areas are having wetter winters).
But there is no substitute for natural rain gently falling on the garden. Rains soak in evenly and deeply, pushing out the summer-long buildup of harmful salts found in our water supply. Even normally irrigated beds appreciate and maybe need those soaking winter rains.
Trees and shrubs not regularly irrigated--including trees planted in parkways--depend on natural rainfall to replenish soil moisture. Even trees and shrubs watered along with a lawn don’t get enough moisture without that occasional deep soaking that rains provide.
Natives and other drought-resistant plants in our gardens that depend almost entirely on rainfall are going to need some deep soakings too. While these plants could probably do without--as the plants in our parched hills will have to do this year--they appreciate any water thrown their way.
While they dislike summer irrigation, most are quite happy being watered in winter, especially in a dry year. I’ve been watering the manzanitas, sages and other natives in my frontyard since the beginning of December, and I can tell you they look a whole lot better than the shriveled-up plants I’m seeing on hikes.
One of the supposed benefits of fall planting is the free irrigation provided by winter rains, but I’ve had to water things planted this fall every few days.
I’m also watering shrubs that are seldom irrigated, such as rosemary, arbutus, osmanthus and ligustrum. Camellias along the east side of the house are full of buds, so I’m making sure they stay moist, even though normally I seldom water these old, deep-rooted specimens.
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Pines, eucalyptus and other large trees, which are usually self-sufficient, may need particularly deep drinks. Once or twice this winter, let the hose trickle several hours (or even overnight) to make sure water soaks deep into the soil.
Don’t simply water right next to the trunk because there may be few feeder roots close to the tree’s base. Trees roots run everywhere in the average-size garden. Figure that roots spread twice as far as the tree is tall. A better spot to water is out near the edge of the tree’s canopy, well away from the trunk (unless of course the tree is very young).
Take a look around your lot and see what plants may not be getting enough water. If you have any doubt, check with a garden spade or trowel to see how moist the soil is a foot down.
It’s amazing to me that so few gardeners actually check the soil to see how wet it is. It’s like driving a car without checking the gas tank. Because gardens seldom have gauges, it’s necessary to dig down and inspect, to find out when a garden is thirsty. Watering lengths and intervals can vary wildly depending on locale and soil type.
Water deeply but not too often. Someone who has to water every few days in summer only needs to water every few weeks in winter, because the soil dries much more slowly in winter.
Try to keep the soil evenly moist, never too wet but never dry: Plants should not be allowed to get bone dry, even plantings of natives and other drought-resistant things. Places you may never irrigate in summer will need water this winter because of the almost complete lack of rain.
Don’t be surprised if the dirt has become so dry that it is water-repellent. You can sprinkle all day and still find the soil mysteriously dry. Irrigation water often takes the path of least resistance and may not soak in where you had in mind. The solution is either to repeatedly turn the water on and off until it begins to soak in or to use some kind of wetting agent, such as Perc-O-Late Plus or Pentrex, which breaks down the soil’s water repellency.
With any luck, Tuesday’s storm will be the first of many; it often rains in February and March. But it’s unlikely that it will rain enough to make up for this season’s late start and shortfall.
Tree authority Bill Evans commented a couple of years ago--after the heavy El Nino rains--that “things sure look good after 30 inches of rain.” Quite the opposite will be true in this dry year if we don’t water this winter.
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In the Garden is published Thursdays. Write to Robert Smaus, SoCal Living, Los Angeles Times, Times Mirror Square, Los Angeles, CA 90053; fax to (213) 237-4712; or e-mail robert.smaus@latimes.com.
