Leymus arenarius or Leymus mollis ?

Leymus in our garden at Lovegrass Farm; grown from seed

I believe this grass to be either Leymus arenarius (European dune grass) or Leymus mollis (Northern beach grass).  I don't mind admitting that  I have a lot to learn about identifying grasses in the wild.  If anyone can help me out here I'd appreciate it!  It would probably help if I had taken a photo of the plant in bloom at the shore but don't often think to bring along the camera when we're going for eel grass.  We've grown our plants from seed wild collected on the north shore and bays where we collect eel grass.  Leymus grows along the coasts in beach sand tolerating salt spray as well as salty soil.  It spreads by rhizomes (underground stems) to form dense clumps. It's soft blue leaves and straw flowers just say Summer & Shore to me!

Leymus grown from seed wild collected on P.E.I.

This is Not a grass to mix in your perennial border but perhaps would be a good choice on saltwater shorelines where you may be battling aggressive weeds or at a cottage.  We've also seen it used in Plymouth, Mass. in a park by the ocean and in parking strips and medians where it will stay confined.

Leymus in a park in Plymouth, Mass.

Leymus used in a median in Plymouth, Mass.