Fire mimicry practices, which involve clearing (shrubs and young trees, especially bays), pruning, trunk care, and amending soils with mineral and organic rich fertilizers, are continuing to have a positive effect on sick oaks here in California. Below are some repeat photography results for several coast live oaks in Carmel, Pebble Beach, Santa Barbara that have been treated with fire mimicry for three years. The main caveat is that the oaks in these pictures, while ill, are not severely diseased. The oaks that are severely diseased are not faring as well. Scroll down to see the results.
However, not all the results are positive. Photos are also confirming that oaks severely affected by stem canker disease are not recovering. Below is an example of a signature oak that is severely infected with a stem canker disease (possibly Sudden Oak Death). While the fire mimicry treatments on this oak may be extending its life by improving the tree’s ability to slow the progression of the stem canker, the treatments are not stopping the disease.
The lower photo shows the trunk of the oak in May of 2008 with the dead bark (killed by the disease) pulled off. Note the many deep cracks in the bark at the root collar. These are likely places for diseases and insect to invade a tree. The deep cracks in the bark are a result of mineral deficiencies in the soil.
The above example is to make the point that if there is an oak tree that you value that has deep cracks in the bark, it would be unwise to leave it unattended. The best way to deal with Sudden Oak Death and other scourges affecting our oaks is to improve the health of the uninfected trees through basic forest care and soil fertilization practices.