“I had the tree looked at 10 years ago and the arborist told me it was fine”.
I have heard this a few times this spring while I was looking at a tree with some serious issues. I can’t disagree. The tree probably was low risk 10 years ago, but it is a living, aging organism, and things change with time.
Arborists may be good at helping you mitigate your problems with your trees in the present. We frequently are not very good at telling you that trees may need some checkups in the future.
If you have a heat pump, it should be checked once or twice a year. You should go to the dentist twice a year. Your car should have an oil change every 3,000 to 10,000 miles and annual inspections. Should you have your trees periodically checked?
If a major weather event doesn’t occur, and the tree doesn’t apparently change, should you bother having an arborist look at it?
The short answer is yes, you should probably have your trees checked occasionally, whether you notice a problem or not. How often should you have them checked is a bigger (and trickier) question.
If I ask “Google” that question, three years is a number that will show up, and that is probably not a bad starting point.
If your trees are smaller and further away from the house and living space, and they generally appear healthy, you could probably stretch that to 5 or more years.
Larger trees that overhang your house probably should be looked at once a year.
If you look at your house’s satellite image and google maps and you can’t see it, you should probably consider having your trees inspected annually.