After the Fire
1. Do not automatically cut down or cut back charred or defoliated trees. Trees may appear dead but are likely to be alive, depending on the intensity of the fire. Do not make hasty decisions!
2. Inspect your property for damaged trees. Determine which are valuable to you. Consider removal of trees that appear destroyed, badly distorted or are insignificant.
3. Remove limbs or trees that pose a threat to significant targets, such as broken limbs overhanging a structure or pathway that is still being utilized. Do not do any other pruning until next spring.
4. Determine if all of the bark is burnt off completely around the stems or if it localized. If the trunk is girdled and the underlying wood is exposed, it will usually result in death of the tree. However, trees can survive localized injury. A qualified arborist can help assess the extent of damage. Time often provides the telltale signs of life and death of a tree exposed to fire.
5. Note that many pines and other coniferous trees to not sprout once defoliated. These may need to be removed depending on the species. Palms may be charred and defoliated, but the single growing bud hidden in the top of each stem may survive and sprout new leaves after a waiting period. Sometimes the charred surface of a palm can be cleaned with a brush being careful not to scrape below the thick fibrous puesdobark.
6. Smalls incisions beneath the bark can determine if the growth layer is alive (except in palms). However a tree is a large organism and can survive even if some areas die. This inspection may be best left to a qualified arborist but should be limited to trees where immediate decisions need to be made.
7. Apply water to the critical root zone. This is a circular area around the tree with an approximate radius of 1’ per inch of trunk diameter measured at about 4.5’ above ground. This is a guideline and not an exact measurement. The goal is to get water to the area with the greatest concentration of roots.
8. Wet the soil approximately 6” deep. Use a soaker hose, rain bird sprinkler, or anything available. Water keeps roots moist and alive and decreases the movement of moisture from living roots to dry surrounding soil. Repeat monthly until commencement of seasonal rainfall.Spring 2009
9. Wait until spring 2009 for new shoot growth to emerge from stems. This is renewed hope for recovery of your tree.
10. At that point, only remove the larger dead branches that do not sprout. The tree shows the separation between dead and live areas. Be very careful not to trim small dead shoots amongst the living shoots. The new live shoots are fragile and are easily damaged from pruning. The tree needs the new leaves to manufacture food for its recovery. Trees that don’t sprout are probably dead. Remove dead trees after the waiting period.
12. Continue to irrigate your tree on a monthly basis except for natives. Oaks can be supplemented with a monthly deep watering if soil is very dry due to to insufficient seasonal rainfall during the previous winter. When in doubt, contact a qualified arborist, who can monitor soil moisture. Supplemental water may be perfectly reasonable for recovery of oaks.
13. Regarding damaged oak trees, I recommend spraying the lower 6’ of trunk in the early spring and late summer with permethrin (Astro). This can resist attack of oak bark beetles, which often kill stressed oaks. Repeat the treatments at least two to three years after the fire.Spring or Winter 201014. Wait another year until spring or winter 2010. After the emergence of new growth during the second spring, the previous years growth should have developed greater mass and become less fragile. With care, begin to prune dead shoots and other larger dead limbs that may have declined over the previous year. It is better to be conservative with pruning to avoid damaging living shoots. It is best to prune oaks in the winter to reduce the potential oak bark beetle attacks, unless trees are treated prior to pruning as recommended above.Spring 2011
15. Wait another year until spring or winter 2011. After the emergence of new spring growth, your tree should be read to begin selective thinning in an effort to restore the crown and establish a new framework of branches. A qualified arborist should be able to perform this work. It is best to prune oaks in the winter as stated above.
16. This three year process is effective in restoring fire damaged trees. There will be structural defects to trees as we’ve seen over many decades. Defects may need to be assessed but should be left to a qualified arborist. Patience, patience, patience is the key!2011 – Future
17. Your trees will warrant pruning over the next few years. The frequency and extent of pruning is dependent on injury, the restoration process that was practiced, weather, and other variables. A qualified arborist can be the link between the health of your trees and their care.