Quick answer: Deadwooding — Pruning is a plan before it is a cut: deadwood and broken limbs first, then clearance from roofs, wires and paths, then the structure the tree will carry for the next decade. The right cut heals and the wrong one invites decay, which is why the order matters more than the number of cuts.
Field note. What we see on this coast is a pruning calendar that does not match the inland one: salt air, fog and wind mean a cut that would be minor in the valley can be the one that opens a crown to decay here, so we look at the species and the exposure before the season.
On the other hand, not every tree wants to be pruned: leaving a healthy canopy alone is a decision that pays, and a tree with plenty of space is often better served by doing nothing.
Deadwooding looks like the simplest operation in tree work: find the dead branches and cut them off. It is not, because dead wood has different mechanical properties from live wood and because the dead branches are often attached to live ones that they can damage on the way down.
What changes when the wood is dead
Live wood is flexible and it holds together under load because the fibres are intact and the moisture content is high. Dead wood has lost that moisture, and as it dries it becomes brittle. A dead limb does not bend and recover the way a live one does — it cracks at the point of greatest stress and the whole piece lets go.
That means a dead limb can fail while it is being worked on, without the warning that a live limb gives. The creaks and the visible flex that a climber reads on live wood are absent or too late.
The attachment is often the defect
A branch dies for a reason. Often the reason is at its base: a canker, a wound, a cavity behind the collar. Which means the attachment point of a dead limb is frequently weaker than the limb itself, and the failure happens at the trunk rather than out along the branch.
So the cut has to be planned from the base outward, and the climber has to be out of the fall path of the whole piece — not just out of the way of the tip.
The order
First: the large dead wood over the target. The pieces that would do damage if they fell on their own. Those come out before anything else, and they come out in the calmest part of the day.
Second: the dead wood over the working position. A climber cannot work under a hanging dead limb, so the crown above the tie-in point is cleared before the climber moves up.
Third: the dead wood inside the crown. Smaller, less loaded, and often in the way of the structural work.
Fourth: the dead tips. Cosmetic and lowest risk, done last so that the crown is not opened up before the heavy work.
What not to do
Do not pull a dead limb with a rope from the ground. A dead limb under tension can break anywhere along its length, and the direction it goes is not predictable from the pull direction.
Do not stand beneath the tree while deadwood is being removed, even to watch. The pieces that come down are not the pieces that were cut.
Do not assume a dead limb is light. A large dead limb of a dense species is still heavy, and it is heavier than it looks because it is dry.
What deadwooding is not
It is not a tidy-up for appearance. Removing dead wood from a mature crown is a legitimate operation at any time of year — there is no living tissue to wound, so the season arguments in oak pruning do not apply.
But removing all the dead wood is not always the goal. Standing deadwood is habitat, and a crown with some dead limbs high in it is a functioning crown. The operation is about the pieces that could reach a target, not about a clean canopy.
Where it stops being pruning
If the dead wood is concentrated on one side of the crown, or if the tree has large dead limbs and a thin live crown, the tree is declining rather than simply carrying some deadwood. Then the question is why, and that is diagnosis rather than a deadwooding pass.