Linda,
I'm so glad to hear the visit went well and wm behaved appropriately! These are the kind of times you and wm need together to rebond after the last couple years of struggles.
I think having wm come back for another hour (seems like a good amount of time - not too long - where he can maintain) and spreading mulch with you is a great idea. It may give him a little boost in confidence to know that he helped his mom.
Hugs,
Sharon