Merry Christmas to you Mayo62
Here, daylilies are really prone to housing aphid colonies. Those that retain green leaves tend to harbor them all during the winter months. Seems like the colonies start establishing and have population explosions beginning in late summer after it cools down. They get really populated sometimes before I notice the damage. During the warm months, I think there must be enough predator insects to keep them under control, but once those begin to fade away the aphids show up. I wish I knew how they got transported around. The dormant daylilies get colonized just as readily as soon as they start to green up and grow. They start growing long before predator insects show up, and until then, I'm the one that tries to keep them under some semblance of control.
I can't really answer your dormant question. I grow some of all types. My guess is that there are some who can tolerate and thrive in warm winters, just as there are some evergreen varieties that manage in cold climates. I know that some of my seedlings exhibit dormant behavior. They don't wait for cold weather to go dormant, so I'm not sure cold is the trigger for them. Day length seems more likely. Some of them die completely down and stop actively growing before it ever gets cold here. The first time they did it, I thought they had all died. Then, after a rest during the winter, the little things woke up and started growing. I'm used to seeing some of them do it now.
