Southmost TX coastal heliconias fading
H. rostrata and H. angusta have been in the ground in my yard here in Port Isabel, Cameron County, the southern most coastal county in Texas, for a year and a half. They've flowered well, multiplied and were looking good until the weather began to cool a month or so ago. Now they are yellowing and sad. My impulse is to cut them down, and compost and mulch for the season.
Since I'm new-ish to the area and very new to tropicals, I'm stumped. Any thoughts?