Ponderosa Pine Question

With the recent fires here in central WA, I have become more concerned about a stand of Pines that are close to my house. A few of the old ones have dead limbs hanging near the ground that would encourage candling should the duff around them catch on fire. I want to trim them up but I don't know what time of year is best for the tree. Also, there is a heavy layer of pine needles on the ground around them. Should I leave them there for the winter? I wonder if they help insulate the roots when there is snow. I appreciate any input.

If the limbs are dead it shouldn't matter when you prune them. I've heard it's generally best to prune live limbs while the tree is dormant, i.e. during the winter and early spring. For what it's worth the forest service usually does pruning during the summer because that's when the manpower is available and the trees turn out fine. Forest trees aren't orchard trees- they haven't been mollycoddled by centuries of cultivation.

As for the needle layer at the base of the tree: unless it's collecting water and rotting the bark away where it comes into contact with them, there's no need to remove them. The thickness of the bark is what gives ponderosa its resilience to fire. If there's any large woody debris that will burn for a while at the base of the tree it should be removed, but leaf litter alone will not produce enough heat to kill all but an already dying ponderosa.

Thanks for the advice Will. I will probably wait until it snows before firing up the chainsaw, it is crazy dry around here. I am relieved I don't have to rake up the pine needles... one less chore

Like Will stated, dead limbs can come off any time with no worries. Live branches of conifers can be pruned when it is convenient for you to be doing it.

As a former smoke jumper in the California Sierra Nevada Mountains, I would remove the pine needles, or at least as many of them as I could.
While it is true they will not produce enough heat to start a tree burning on their own, they do allow bridging of a fire and that is what a fire break is all about.
Stopping the bridging by a fire using small stuff and "duff" to make the jump to the next tree line is good home owner fire control.
One other thing, wind whip can be a big issue in a fire, I've seen flames bridge 100 feet of clearing just because of high winds. Oh, and big fires create their own wind.