Wow !!! Great.
I have tried loads of stuff, but sadly most havent taken. Mostly because of our ignorance....... we tried mirabelles ( some type of small green prune that we love, my parents have a tree in the garden ), quite a few times. Even got the seeds to germ. Then someone back in europe pointed out that lots of fruit trees needed to "hibernate" in winter. And sure enough mirabelle trees need to.
Anyway on the "legal " side.
Years ago we sent boxes, through a "money sender" who send containers by boat from switzerland. ( well by road than boat, I suppose:nervous
In them we put loads of commercial seed packets of flowers and vegetables. We had to fill in a form with everything in the boxes, which we did. No one said anything.
Now we just bring them over in the suitcases. ( kind of a problem transiting through the states ).
We have now calmed down on planting stuff and are now "concentating" on local flowers, vegs and trees. ( I suppose that after all there are reasons for some stuff to grow amd other not:surprised ).