There is no easy solution. Digging it up will be the only way to be successful without injuring the tree. Maybe you can invite some friends over on a weekend, stock the fridge with beer and pick up some cheap shovels at Wal Mart so no one goes wanting.

Here is a link that might be useful: Propagating Perennials

Fatso, I was hoping someone would come up with a magical cure. I have a similar problem, except it is pachysandra growing underneath blueberry bushes. The blueberries are getting choked out-they are not producing like they used to. I tried yanking the pachies, but they are tenacious! I tried putting newspaper down, but I can't even tell where I put it! Anyone have any ideas?

Unfortunately, the only way I have succeeded with Pachy removal has been years of pulling and pulling. It gradually gives up (although it continues to come up in very small patches years later). It's still worth the effort.Better now early in the season before it gets really thick and happy.
N

Thanks Nancy0903. I have been yanking it out from where it is encroaching on my perennial garden. It has been such a chore that a shiver when anyone talks of planting pachysandra!