Putting the raised beds in an area where there are no roots now won't hurt existing or future tree roots, however, as you noted, the tree roots may eventually not be great for your beds.

as far as trees with invasive surface roots.. oaks is one of the LEAST problematic ... if ever ....

me thinks you need to find something else to worry about ...

ken

As long as you don't pile up soil around the trunks and change the grade for the trees, woody ornamentals will be fine but after several years the pansy ritual will end.

Dan

thanks for the replies. Good to hear. I was more worried about stressing the tree than the roots bothering plantings in the beds.I can replace perrenials cheaper than a tree especially after the tree gets some size to it . thanks all