Can a robot mower be used in a garden that has trees?

Without a perimeter wire (Satellite guided-robots):

Most RTK robots will struggle with tree cover. It is extremely important to purchase a robot with complementing technology, such as advanced camera systems (found in new Segway Navimow and Mammotion Luba 2 platforms), designed to take over where RTK fails. Even still, extremely large swathes of trees may still pose issues, so professional guidance is essential. Generally speaking, single trees and small groups of trees can be tackled with the use of these new advanced camera-enhanced robot lawn mowers.

Where trees have protruding roots of potentially restrictive trunks, creating no-go zone from within the Mapping software is advisable.

With a Perimeter Wire:

If your garden has trees then it’s not a problem. If the trees do not have any protruding roots then you can just let the mower bump into them as they would do any other obstacle. If the roots are protruding then it could cause the robot to ‘ground out’ i.e. lift the wheels off the ground.  This can be solved quite easily by either creating islands with the perimeter wire so the mower keeps away from the tree or by putting a raised barrier around the tree so it bumps off it.