Chatsworth : Oak Trees Rebound After a Wet Winter

Q uercus agrifolia never looked better.

The dozens of California live oak trees--known in the botanical world as Quercus agrifolia-- that were dying in the Chatsworth Reservoir area last September are on the mend, city officials say.

Agrifolia --along with Quercus lobata , the California Valley oak--was under siege from bark-munching “twig girdler” beetles and from ground squirrels, which bored holes beneath the trees, preventing moisture from reaching the roots. High levels of air pollution and serious drought further weakened the trees.

But above-average rainfall this winter helped strengthen the low-slung, broccoli-shaped trees and allowed them to stave off the beetles, said Mindy Berman, a spokeswoman with the Department of Water and Power. In addition, DWP workers backfilled the warren of holes and divots dug around the trees’ roots by squirrels.

Last year, DWP officials considered spraying insecticides to eliminate the beetles, raising concern among some residents who live near the perimeter of the reservoir. Now, spraying will not be necessary, Berman said.