Five year results of fire mimicry on oaks in Hillsborough, CA

Last week I inspected several coast live oaks that have received three fire mimicry treatments over the past five years. A couple of these oaks have bleeding stem cankers (probably Sudden Oak Death) that have been treated surgically as well. It will be a few more years before I know if the diseased oaks have recovered, but in the meantime these and the other uninfected oaks appear to be doing fairly well.

A couple of the oaks have lost a few limbs in the storms this past year, but are otherwise healthy. I should add that the wet winter has played some role in the improved canopies, however, results from these same oaks in prior years (2013, 2015) indicate noticeable improvement even under severe drought conditions.

Oaks in Glen Ellen, CA responding to fire mimicry

Seven years ago I began treating a group of coast live oaks with fire mimicry. Several of the oaks are infected with bleeding stem cankers, probably Sudden Oak Death. Despite being diseased, the oaks have shown a steady recovery over the years as can be seen in these photos from 2013, and 2015. On Tuesday I checked on these oaks again and as the photos here show their health, for the most part, continues to improve.

For all the fear-filled hype about diseases and insect pests ravaging our forests, I find very little news about the fact that, whether or not the trees are infected with this disease or infested with that pest or stressed by climate change, sick trees can be brought back to health. I know this from doing the work, treating sick trees, and seeing the results such as these.

Lebanese cedar trees in Los Altos, CA improving with fire mimicry

Six years ago I was approached by a property owner in Los Altos, CA who had two large Lebanese cedar trees, one of which was not doing well. He had been advised by another tree expert to remove the sick cedar. This cedar has some sort of bleeding stem infection at the base and a fairly thin canopy. Rather than removing it, the owner called me to assess the problem. I told him frankly that I had no experience treating Lebanese cedars, but that it may be worth a trying the fire mimicry treatments I had been using to improve the health of oaks and other trees. He decided to proceed with the treatments. I applied a mineral poultice to the base of the sick cedar and amended the soils with an alkaline-rich blend of minerals and compost tea to both the sick cedar and the adjacent healthier cedar. I have repeated these treatments three times in the past 6 years. In just a few years there was noticeable improvement in the cedars. On Wednesday I checked on these trees again and found that both have continued to improve. Before-and-after photos of the two cedars are shown above and below.

There are many sick trees that some tree experts say there is no recourse other than to remove them. While this may be the only option is some cases, I’m now convinced that it is often not necessary to remove a sick tree. There are any number of techniques for saving trees that conventional tree experts are not using, such as soil fertilization, removal of mosses and lichens, poultice application to the trunks, and surgical removal of infections, and cauterization of wounds. Together, these techniques can make the difference between removing a tree and saving a tree!