Based on my experience, if the temperatures get really cold, they need good snow cover to survive, so if you had a particularly cold spell without snow, they may not have survived. The particular cultivar you have matters as well. Lucifer is the hardiest. I haven't been able to overwinter any others, though I have tried. I am not sure, but I think the voles in my garden eat some of them as well, though they aren't a favorite food or there would be none left.

Sorry I was in a hurry due to the word limit. I tried less water, I tried more water. Less sun and more sun. I tried small amounts of fertilizer. I cut more holes in the planter to make sure it was draining properly. The snails were nipping at them but that shouldn't kill off an entire vine so I treated for bugs and for fungus. Nothing seemed wrong with them other than some holes in the leaves (from the snails) and the fact they were dying. I believe it's Miracle Grow Garden Soil in the planter. The morning glories are the only thing in there except the trellis. I figured being vines they choke anything else out. Many of my neighbors have them basically growing wild. I have no idea why mine just died when they were doing so well. Any advice for next season would be appreciated.

I find that they usually go some distance away to pupate. I have a difficult time spotting them. I noticed yesterday that my really big milk weed was stripped clean and the cats were all fat. Today I was able to find two chrysalises because they did not hide well. One is up under the eaves and the other just stuck itself to the outside of the screen. I hope he makes it.

Earthworms need organic matter, that is what they live on. How much is in the soil?