Very well established pampas grass killed by frost. Have almost killed myself, removing all the base plant. Thinking of siting a raised bed here now for vegetables . Any danger of any roots re-shooting into my veg? would you consider cardboard or black fabric on the base?
If the plant was dead and you have removed all the shoots and left only roots, there is no chance of re-sprouting. On the other hand, if it was not quite killed by frost and you have left the base of the shoots, it could easily re-sprout.
If you are not sure, you could apply Roundup to any remaining bits of stems and this will kill it.