Been there, killed that! Didn't have any luck with bluebells myself. Got blooms the first year, but it never returned.

But they are beautiful when happy!

Try to find a site that remains moist-not wet- thruout the warm months. To this site dig in a good quality compost or a potting mix and allow it to remain untouched until cool weather. At that time, t-plant the Mertensia using plenty of extra potting soil. Be certain that the site is shaded.
Good Luck.

I've never been able to keep them going from commercial transplants; I think they object to being moved. Somewhere, I read a hint that virginia bluebell/mertensia seed should be planted immediately after harvesting. A few years ago, I took some stems with seed [with permission, from along a neighbor's creek] as soon as the stem appeared to be mostly dry; wrapped them in a damp paper towel for the long drive home and then planted the stems (with the seed pods attached) immediately in the shade garden. They did take 2 years to get to blooming size. Since then, they've been happy enough to bloom beautifully and multiply nicely, in spite of all the drought. Actually, they have multiplied so well that 2 years ago, I tried transplanting a few to a different area -with less than mediocre success- however, the plants which lived through the transplant did bloom this year. Both sites are in dappled shade, with many years of mulch worked into the soil. Unfortunately, they rarely get watered during droughts, but that doesn't seem to have affected them.

I live in NOVA and have had some for several years. I even dug up the bulbs last year and moved some from full shade to full sun and have had plenty. I have a dry woodland backyard, and with the drought we had last fall and recently, I cannot believe I still have them. I am not trying to rub it in---there are plenty of things I have tried in my backyard too that I never have luck with---such as Astilbe and Lily of the Valley

You can have some of my Lily of the Valley (difficult to get rid of) if I can have some bluebells :).