Thanks for your question.

There is good and bad news. The good news is that you are correct in identifying the stalk-like plants as hostas. The bad news is that the other plant is the dreaded creeping bellflower (Campanula rapunculoides).

I have dealt with Creeping Bellflower repeatedly over the years and have arrived at certain thoughts:

1). There is no quick and dirty way to get rid of it. Once established, it stays established. Even if one continually digs it out, it is virtually impossible to remove all root bits and pieces that go on to produce new plants. It releases prodigious numbers of seeds in the fall that are wind carried to innumerable locations. These seeds may remain dormant in the ground for several years until favorable conditions arise for their germination.

2). What real harm does it do? If it is in a location where it doesn’t compete with more favorable plants, is it worth it to try and eradicate it from that location?

3). The presence of Creeping Bellflower may perturb one’s ideal of a neat, tidy, and well-organized garden. Unfortunately nature is not designed to do this. This is why many gardeners have now gone over to more “natural” gardens.

4). The use of herbicides to eliminate Creeping Bellflower is fraught with danger to nearby plants. Using a non-specific herbicide (e.g., Roundup) that contains glyphosate will kill the bellflower plus everything else in the area.  Broad-leaf herbicides (e.g., 2,4-D) are ineffective.

Unless you are willing to spend long hours on a regular basis digging, Creeping Bellflower is now part of your perennial garden. Decide exactly where you do NOT want it to be present. Direct your attention and efforts there and let the Creeping Bellflower do its thing in the other areas. However if you would still like to battle this plant, remove all emerging flower stalks before they develop flowers. This would decrease the amounts of seeds that they would otherwise release.

See the following for information on these and related points:

https://northerngardener.org/creeping-bellflower/

https://www.gardeningknowhow.com/ornamental/flowers/campanula/removing-creeping-bellflower.htm

https://blog.yarddawgslawncare.ca/creeping-bellflower-removal - :~:text=If you're prepared to,the top of the plant.

https://hennepinmastergardeners.org/invasion-of-the-creeping-bellflower/

https://apps.extension.umn.edu/garden/diagnose/weed/broadleaf/creeping/bellflower.html

https://apps.extension.umn.edu/garden/diagnose/weed/idlist.html - CBellflower

https://extension.umn.edu/weeds/creeping-bellflower

https://hennepinmastergardeners.org/invasion-of-the-creeping-bellflower/

Good luck. Thanks for consulting us.