I fear you will get no 100% answer.
Yes~~ with many people it can be invasive. "The sweetest weed" was once
used as a description. It can take a number of years to become established
and then will start to spread. Some growers use some form of physical
barrier to resist creeping.
No~~ I have never been able to grow it myself despite a large garden and
many attempts. Just minute patches with a few flowers.
Plants can be choosey. I cannot even get Vinca to grow even though it
covers a bank only 200 yards away!! All other plants do well.
Best Wishes Brian.
wrote in message
...
What is your opinion of Lily of the Valley? A local garden center said it
was recommended that they not sell them as they are so invasive.

Thanks!