Once you have jumping worms in your yard the best you can do is manage them. Jumping worms mature in late July. Once you realize you have them do not share plants from your yard with others. You can dig them and wash the roots well but three is really no guarantee that there will not be eggs laid on the roots. 

You can report your location to the DNR. 

And Manage your reaction to having them. Unfortunately, we will all have them in time. 

You may want to share this information with your client so that he/she is aware and not sharing without telling others first. Maybe they don’t know they have jumping worms but sharing the information is best.

https://extension.umn.edu/identify-invasive-species/jumping-worms

https://www.dnr.state.mn.us/invasives/terrestrialanimals/jumping-worm/index.html

https://mitppc.umn.edu/research/research-projects/jumping-worms-minnesota