My daylillies are dying. Even the biggest clumps are dying down to the ground. It has been an extremely hot summer here in Louisiana. Could that be it?

hi stella i am from nova scotia but i have day lillies here and ther are perianell as far as i know and they come back every spring. maybe it is the heat?? but not too sure, about them in warmer countries. they do seem to be a real hardy plant though,hope u find out? good luck jo!