A few weeks ago, the Town Crier received a letter from a resident concerned about the currently active pruning of trees.
The author wrote, “I just stopped Asplund … from further cutting my pine tree. It is the worst time of year for cutting pines and introducing pathways for bark beetles. The tree they were cutting is under stress and fighting off a bug in the needles that John Huddleston of Precision Tree Experts treated. This pruning at this time of year only harms the tree.”
While local forestry officials agree that spring harbors more dangers than fall, the issue is more than just the threat of bark-beetle infestation.
“Fire danger is just as much a problem as the bark beetle,” said Gregg Bratcher, the unit forester for the Cal Fire, Riverside Unit. “Nobody wants to potentially attract the bark beetle, but the impending fire season with the fourth year of drought is not good.”
Both Bratcher and former unit forester, Kevin Turner, agree that pruning pines in the spring can attract beetles, not just the bark beetle.
“Because engraver beetles like ips and bark beetles are attracted by terpenes exuding from fresh cuts in live tissue and the beetle population is so high right now, I believe it would be best to defer pruning until later in the year for live branches,” Turner said in response to the question. “Dead branches could be pruned if done correctly.”
And Bratcher stressed that if the whole tree is being cut down, the danger is nonexistent.
“If you just examine the physiology of the tree,” Bratcher said, “the best time is in the fall. Beetle activity is less then. But if the pruning is done to standards, the wound will heal up nicely.”
Another concern about delaying the work until fall is the availability of workers and the weather, Bratcher added. Edison has a fixed number of contractors cutting and trimming trees in a huge area, including the San Bernardino Mountains. The fall tends to be wetter, therefore reducing the opportunity to complete the tree work.
“Fire work is year round,” Bratcher concluded.