Posted: 15/12/2013 at 00:12
I suspect, very strongly, you have vine weevils. Heucheras are a passion for those critters. Use Provado vine weevil killer ASAP
I suggest, yes, you cut all,those leaves off..it clears away all the debris and helps prepare it for new leaves in the spring.
Next spring you could use nematodes for vine weevils....the preferred organic way....but you can't use the chemical and the nematodes together. By next spring the chemical in Provado will have disappeared.
Whatever you use you will need to treat Heucheras twice a year.....spring and autumn