I’ve killed and dug up four yellow jacket nest here on the farm over the years. They have all been about the size of a soccer ball. Hopefully it won’t hurt your tree, you could wait a few months to relocate the tree this fall. Anyway, this is my method. 1st, wait till night time. 2nd, take some diesel (it don’t take much) and soak some paper. Roll the paper up like a wick or funnel shaped and stick in the yellow jacket hole. 3rd, light and listen, most of the time you can hear them buzzing. As the diesel soaked wick burns, it pulls the oxygen out of the nest. They will suffocate and die. 4th, go to bed. The next morning, grab a shovel and dig out the nest (it will be like a round grey paper ball, with layers and layers of different levels stacked inside). The queen is easy to pick out, the workers are half her size. Good luck with your little trees. I would probably wait until the fall, that way you could replant the tree where you want.