Tree trimming before storm season: what to cut, when, and what an arborist checks

When a summer storm crosses the northwest suburbs, the tree calls that follow are rarely about healthy trees. They are about the dead ash that finally gave up, the silver maple limb that had been cracked since last year, and the branch overhanging the roof that everyone meant to have cut. Trees in mature neighborhoods like Park Ridge, Barrington, and Mount Prospect add real value and shade, but they are infrastructure, and they need inspection on a schedule like everything else on the house.

The best trimming window for most species here is late winter into early spring, while trees are dormant and before leaves hide the structure. Dormant work is also the rule for oaks: to limit oak wilt risk, Illinois guidance is to avoid pruning oaks during the growing season, roughly April through October, because fresh wounds attract the beetles that spread the fungus. Elms carry a similar dormant-season preference for Dutch elm disease. An arborist who proposes topping an oak in June is telling you something about the arborist, not the tree.

What should a trimming visit actually remove? Dead wood first, because it falls without warning and it is what insurers and neighbors notice after a storm. Next, crossing and rubbing branches, weak unions where two trunks squeeze together with bark trapped between them, and limbs hanging over the roof, driveway, and the neighbor's yard. Clearance targets are simple: branches at least six to ten feet above a roof surface and clear of the chimney and service drop. What a good visit never produces is a topped tree, cut flat across the crown. Topping destroys structure, triggers weak regrowth, and is rejected by every arborist standard, no matter how confidently it is sold door to door after a storm.

Costs scale with size and access. Trimming a mid-sized shade tree typically runs $400 to $1,200, with large oaks, tight backyards, and crane work pushing higher. Removal of a large dead tree typically runs $1,000 to $3,000 or more, and stump grinding is often quoted separately at $150 to $400. Ask any quote to state disposal, whether wood is hauled or left, and cleanup, because a low bid that leaves a yard of logs is not the low bid it looked like. Verify insurance in writing; tree work is one of the trades where an uninsured crew's injury becomes the homeowner's problem.

Between professional visits, walk your own trees twice a year with binoculars. Look for dead branches in the crown, mushrooms or conks at the base that signal internal decay, a trunk that has developed a lean it did not have, cracks or seams in major limbs, and soil heaving on one side of the root zone. Emerald ash borer has already decided the fate of untreated ash trees across the suburbs; a dead ash becomes brittle fast and should be scheduled for removal promptly rather than watched.

One more local note: parkway trees between the sidewalk and the street usually belong to your village, which trims and removes them on its own schedule and its own budget. Call the village before paying anyone to touch one. For the trees that are yours, the directory lists tree services across the northwest suburbs with ratings shown where available; look for a certified arborist on staff, and book the assessment in late winter before the spring rush.