I don't think you would need to worry about "fumigating" the soil for something so un-established (but am not an expert on this)......and I definitely don't think you would need to worry about even replanting.....I agree with Hman's perception and would be willing to bet that this tree will re-sprout. Am continually amazed at how sturdy trees (and fruit trees) are.....I don't believe I have ever killed one by pruning.....am also amazed at how much people are worried about killing them by pruning too much or at the wrong time, etc, etc. Trees need care, yes, but they are also tough.....often tougher than we think. The story of one of our oldest pear trees, the Endicott Pear, is almost a comi-tragedy at just how many times this pear tree was destroyed......only to come back to life again.....year after year....for literally hundreds of years. Try getting a link here. http://en.wikipedia.org/wiki/Endicott_Pear_Tree

It's not unusual for these bare root persimmons to not leaf out until August, and I've heard of cases where they didn't leaf out until the following spring. This is caused by transplantation shock from improper care of the roots. So perhaps all is not lost, but it does not speak well of the nursery that sent the trees to you. It may be wise to contact them now about the problem in case they later need to be replaced.

I am aware this thread is over a decade old but it pops up on google when you search for pawpaws in Savannah, and I just wanted to make sure everyone knows that YES, pawpaws are native to Savannah, it's just that dwarf/small-flower pawpaws (asimina parviflora) are more common this far south than common pawpaws (asimina triloba). I've found OVER thirty small-flower pawpaws on Roger Warlick Drive, along the walking path that leads to the recreation field, as on July 14th 2021. Many of the plants even have fruit, and there are more on the other side of the road as well! If you are also wandering here from google, looking for where to find pawpaws in Savannah, Georgia, check out iNaturalist.org, / iNaturalist, it's a world-wide database of plants and animals that people submit, so you can find any plants that people have found in your area! Even if none show up where you are, don't be dismayed! You might be the first person on the site to obverse them, like I was with the /literally more than thirty/ plants I found just in a few days of looking! The more people who add to the database, the more locations we'll be able to share! None of the pictures are showing up from the earlier posts, but iNaturalist is also an awesome way to learn how to identify the plants, because you can see hundreds of examples, taken at all different times of the year! Long post short: Pawpaws can 100% be found in Savannah, Georgia, it will just most likely be the smaller small-flower pawpaws instead of the larger common pawpaws. But if just one person has a pawpaw tree that animals are allowed to eat from, those seeds will spread and common pawpaws might become more common here too! Don't give up hope! Check out iNaturalist to see if there are any that have been seen near you, and even if there aren't, it doesn't mean there aren't any, it just means you can be the first to add them!

I do get the sense that to some degree pawpaws are being exploited for their trendy marketing value without regard to putting out a product that even vaguely introduces the consumer to the flavor of pawpaw. I've tried pawpaw beer at the Ohio Pawpaw festival and then more recently from a local brewer, and while I enjoyed the beer, I and others could detect no hint of pawpaw in either concoction. Now with ice cream, having made a few batches I am gaining an understanding about how easy it is to go from undetectable pawpaw flavor to overpowering pawpaw flavor by adding just a small amount of extra pulp. It reminds me of one of those awful hotel showers where the water goes from scalding hot to freezing cold with a tiny turn of the knob.