Valley oaks in Walnut Creek, CA respond to fire mimicry

I recently inspected a grove of sick valley oaks that have been treated with fire mimicry for the past two years. The results are very encouraging. Most of the oaks have responded with a noticeable increase in canopy greenness and density. Note that valley oaks do not contract sudden oak death disease, but are still declining in many places. They, too, are generally suffering from a lack of ground fires. Fortunately, these results point to a way forward for improving the health of our great valley oaks using fire mimicry practices.

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Recovery of oaks following the 2017 Sonoma fires

Yesterday I inspected a grove of oaks that had burned during the 2017 Sonoma fires.  Previous to the fire these oaks had been treated with fire mimicry, which included pruning the lower branches (ladder fuel), clearing away underbrush, removing mosses and lichens from the trunks, fertilizing the soils with compost tea and soil minerals, and applying a limewash to the trunks. During the fires all of the ground vegetation burned, but none of the flames spread into the upper canopies. Thus, all of the oaks survived (as did several nearby homes), and, as the photos show, are doing well after 1.5 years. A caveat – these results are influenced by the spring flush of new leaves, and a better comparison can be made when I visit the site again this October.

These findings represent the combined effects of a ground fire AND fire mimicry treatments on improving the health of California oaks.