The same treatments that make trees healthy and beautiful also makes them fire resistant. Pruning out dead and low hanging branches, proper watering and clearance from structures all help. Here is a link for more information: readyforwildfire.org
The value of a 2-3" layer of mulch over the rooting area of your tree cannot be overstated. Mulch improves soil fertility and texture, moderates soil temperatures, controls weeds, prevents water loss, erosion and compaction. Solano Shade Tree has an abundance of organic wood chip mulch at low or no cost. Here is a link about mulching: UCIPM mulch
Borer insects are a bit like vultures, they prey on the weak, dead and dying. The best defense is simply maintaining your tree’s general health so it does not get an infestation in the first place. Proper irrigation, mulching are much more effective than pesticides.
Over or under watering is the most frequent cause of tree problems we see. To make things more complicated, the symptoms of drought and drowning look the same in plants. Trees need a different approach to watering than other landscape plants. Here is a link to a blog from one of our colleagues to help: effectivetreeirrigation