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EAST COUNTY
The statewide drought might be affecting trees — in the outer East Bay and beyond — that are better suited to life in other parts of the world.
An unusual number of calls are coming in to the UC Cooperative Extension from people asking why their camphor trees and liquid ambars — trees they've never had to water until now — are wilting.
"This year we've had so little rain that for trees that are not adapted — and even those that are — there is simply no moisture in the ground except for (what) we are applying," said Bethallyn Black, manager of the agency's urban horticulture program in Pleasant Hill.
Some areas have even less water in the ground because the water table, the underground water supply, has fallen below the reach of trees whose roots have not adapted to a Mediterranean climate, she said.
Although trees from that part of the world such as cypress, eucalyptus and juniper are adapted to hot, dry summers and wet winters, these seasons are the opposite in most of the non-Mediterranean world — wet summers and dry winters, she said.
As such, trees and other plants indigenous to places like Asia and the eastern United States can have trouble when the climatic difference between the East Bay and their native environments becomes even more extreme.
There isn't enough information on East County's water table to know
Most of the semiannual measurements from seven wells that the state Department of Water Resources has monitored over the years are outdated. The one it's still tracking in the Pittsburg area shows a negligible drop over the past two years, although that's fairly typical considering its proximity to a large body of surface water such as the Delta, said Chris Bonds, a senior engineering geologist with the department's Central District office in Sacramento.
Rainfall totals for Brentwood, Oakley and Pittsburg offer a clear picture of the drought. Measurements for each of the three cities in 2007-08 were lower than those taken several years earlier, although this past year was considerably wetter than the one before.
Still, environmental experts agree the entire state is pretty parched right now.
Plants that have survived dry conditions until now without help from sprinklers or hoses have managed to tap into sources of water nearby, she said, noting that a long-abandoned vineyard in Oakley still produces grapes thanks to an adjoining irrigated cornfield.
Because that subterranean moisture is harder to come by this year, tree roots that don't normally move aggressively into flower beds are spreading laterally toward irrigated gardens because they can't find water by stretching downward even just several feet, Black said.
And as they suck moisture from man-made landscapes, the supply must be replenished.
"People are telling me ... they need much more water to keep plants from being stressed," she said.
The combination of another dry winter and some water districts imposing use restrictions has been prompting more people to consider planting hardier gardens, said Kelly Marshall, a Clayton landscape designer who specializes in native species that don't require much water.
"Almost every call is, 'I want to get rid of my lawn or reduce my lawn,' " she said, noting that in recent months more people have contacted her wondering what kind of plants they can use instead.
Marshall is working on a dozen drought-resistant landscapes from Castro Valley to Brentwood, including one in a Concord neighborhood where she's replacing lawns with succulents and blooms that attract butterflies.
Reach Rowena Coetsee at rcoetsee@bayareanewsgroup.com or 925-779-7141.
Alameda County residents can call the Alameda County Water District's water conservation specialist for advice and free brochures at 510-668-4207.
