I just bought a Burning Bush. I live in zone 5. Is there anything I should add to the soil since I am planting a little late in the season, to assure it makes it thru the winter. How deep do I plant the root ball? Is it like most plants/shrubs where you leave the top of the root ball slightly above the soil, or should it be a little deeper? Thank you.

plant as with any other planting, keep well watered throughout the winter, mulch around the planting to retain moisture and protect the root ball from freezing.
good luck