I'm not sure if this is the answer but what about pre-emergent in the spring sprinkled in the coral bell to prevent grass from coming up. I have never done this, just a thought.

Les, I had to do exactly that! I got a few in trade. Nothing was in between when I planted them (or so it looked), but not long afterward, I had grass, apple trees and pesky weeds that were new to my garden! I dug up each plant, and soaked in a bucket of water. That made it easier to tease out the weeds. I kept no dirt on them, but replanted as completely bare root plants.

It was actually much faster than it sounds. Soaking made it much easier.

It seems to me that Heuchera are as forgiving as hosta, replant all you want if you don't strip the fine roots right off the stem. And getting rid of quack grass means doing just that.

Take RoundUp (glyphosate) and a small paintbrush. Make a solution product to water 1 : 5 with a drop of detergent and dab the grass. Wait for good weather. It will take two week to kill the gras - completely.

When you get rid of the grass apply 4" of wood mulch under & around your Heucheras. This helps block weeds & keeps moisture around the root zone. Your Heucheras will love it :)

Les, I think that's probably your best bet. I don't think pre-emergent would work, since the grass is probably KBG spreading by runners from the lawn.

Deanna