This is a response to the passion fruit answer in your column. I have a friend who owns a large track of land in southwest Missouri. It's covered with large patches of purple passion flower/fruit. I wanted to share this, as I keep reading it tropical or subtropical. We have winter temperatures that dip below zero. We can have heavy snows and lots of frost. My friend has owned this property for 5-6 years and it came with the passion flowers. Given the size and density of the patches and the fact that it's found over much of his 1400 acres, I would have to guess it's grown there for years. It's thriving and now has lots of golf ball sized fruit.
Certified GKH Gardening Expert
Thanks for sharing. There are tons of passion flower varieties, all having variations in their hardiness, and some are even native to the U.S. and considered semi-tropical. These will even over winter in zones 5-6 with some protection, while others handle temps down to 28 F. I am assuming that this would be one of those varieties. For more information on the various types of passion flower plant, this article will help: https://www.gardeningknowhow.com/ornamental/vines/passion-flower/passion-flower-varieties.htm