What sets the interval
Fast, soft-wooded trees such as cottonwood, silver maple and Siberian elm drop dead wood and grow long limbs, so they need more frequent attention. Slow, native evergreens such as pinyon and Jeffrey pine often need little beyond dead wood and low limbs. The site matters as much as the species: a tree over a roof or driveway gets looked at sooner than one in the back corner.
The ISA's rule is that no branch should be cut without a reason. A tree with no hazard, no dead wood and no clearance problem does not need a cut because the calendar says so.
Why yearly shearing does harm
A tree cut to the same shape every year is wounded every year, and each cut invites a flush of sprouts that must be cut again. Heavy, frequent work trains the tree to make weak growth. See how much of a tree can be pruned at once.
A practical rhythm
We do not publish a number of years because we cannot back one with a source for every tree. A reasonable pattern is to have a certified arborist look over each mature tree now and then, after storms and after any dry spell, and cut only what that visit finds. Dead and hanging limbs can come out at any time of year, and other pruning is usually done in late winter for deciduous trees. Our timing guide covers the season.
Young trees are different. Structural pruning in the first years sets the shape the tree will carry for decades, and that is lighter and more frequent work.
What a visit looks for
The arborist checks dead wood, crossing and rubbing limbs, tight forks, limbs over structures and signs of decay. The visit is free and ends with a plan. Call 775.232.8243 or use the estimate form.
Storms and dry years
Check mature trees after each major wind or snow event, because a limb can crack without falling. A dry year is another reason to look, since dead tips and drought stress show later. See heavy wet snow and broken limbs. These are reasons to inspect, not to cut.