Q.plants for retention ponds
will cardinal plant live on the edge of a pond in southwestern Florida

Cardinal flower loves moist soil but does not like to be in wet soil during winter dormancy which may cause root rot. . It is also a short-lived perennial so must be encouraged to self-sow. It is gorgeous and loved by hummingbirds and hummingbird moths like the sphinx moths. To attract wildlife, make sure to plant at least 3 of them. An isolated plant won't be worth the trip; hummingbirds are looking for larger feeding areas. Or combine cardinal flower with bee balm which hummingbirds also visit. So the answer to your question depends on soil moisture levels in winter.