When a certified arborist's eye matters most
Some tree situations are pretty clear-cut. A dead tree is usually a removal job. A stump needs grinding. But other situations call for someone with deeper tree health knowledge before you decide anything.
UNL Extension lists seven signs that a tree may need a professional evaluation: decay, conks (those mushroom-like growths on the bark), cracks, girdling roots, co-dominant leaders, leaning, and root plate defects. If your tree has one or more of those, asking for a certified arborist specifically, rather than just any crew, makes sense.
Storm-damaged trees are another case where it pays to slow down. The Nebraska Forest Service advises dealing with loose hanging branches and split trunks first, but for the rest, there's often no need to rush. If you can wait up to a year to decide, the tree may turn out less damaged than it looked right after the storm. A trunk split down the middle, though, should be looked at by a professional arborist promptly.
Ash trees and the arborist decision
If you have an ash tree that's thinning, the Nebraska Forest Service has clear guidance: only consider treatment if emerald ash borer has been found within 15 miles of the tree AND the tree is healthy and in a good location. Weighing tree health, location and how close EAB is: that is a good call to ask an arborist to help with.
Trunk injections are not a DIY project either. The NFS says that job belongs to a certified arborist, and the Nebraska Department of Agriculture requires a commercial pesticide applicator license for tree injections done for hire.
Pine wilt, bagworms, and other tree health concerns
Sick pines and stressed junipers are two more situations where a knowledgeable eye helps. Pine wilt kills mostly Scotch pine, sometimes within weeks to months. UNL Extension says pines dying between May 1 and October 1 should be cut down promptly and the wood burned, buried, or chipped, not kept as firewood.
Bagworms can seriously stress or kill junipers, arborvitae, spruce, and pine. Timing matters: spraying works from late May to mid-June, and by late August it no longer works. If you're not sure what you're dealing with, a contractor with arborist credentials can help identify the problem before you treat or remove.
What credentials to ask for
Nebraska does not require arborist certification by state law, so asking the right questions is on you. The Nebraska Forest Service recommends asking for proof of Nebraska Arborists Association or ISA certification. You can verify an ISA Certified Arborist yourself at treesaregood.org.
The City of Omaha has required a city arborist's license for paid tree work. Ask to see it, and confirm with the city.
Also ask for certificates of insurance for both liability and workers' compensation, and call the insurer to confirm coverage. Nebraska contractors must register with the Nebraska Department of Labor; you can search at dol.nebraska.gov. The BBB of the Midwest Plains, based in Omaha, is another place to check a company's record.
Get more than one estimate. The NFS notes that estimates far below the rest are worth being cautious about, and that reputable companies rarely go door to door.
Frequently asked questions
Do I need a certified arborist for every tree job?
Not necessarily. Routine removals and basic trimming don't always require one. But for sick trees, hazard evaluations, or ash tree decisions, asking specifically for a contractor with arborist credentials is a reasonable step.
What does "co-dominant leaders" mean, and why does it matter?
Co-dominant leaders are two stems of roughly equal size growing from the same point on the trunk. That kind of split can make a weaker attachment. It's one of the seven signs UNL Extension says warrants an arborist's evaluation.
Can I verify a contractor's ISA certification myself?
Yes. The International Society of Arboriculture lets you verify a credential at treesaregood.org before you hire.
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