can I save Mimosa saplings?

My mimosa tree sheds it's seed pods in the fall, and lo and behold, these little saplings are growing in my chainlink kennel. I will need to use the kennel in a week, and have a 160 foot fence line that needs some trees for my donkeys to have shade. can I dig up these saplings with their dirt and put them in containers to root and grow all summer then plant in fall? I know these grow incredibly fast but how to dig them up without killing them? Just make sure they have a little rootball? in 2 years my fence line will look amazing lined with these trees.