I know this may sound crazy, but are you talking fig tres that have fruit on them, or those ornamental ones? I love figs and would love to have a tree! Do they grow outside on in large pots? I live in Missouri 6a. Thanks!!

Yes, it is amazing.
However, I believe it is not because it was Chicago Hardy but most probably something to do with its late summer care history. I have a number of Chicago hardy plants in Zone 5a. Each year I find a plant or two ignoring the fall ritual of dropping leaves and continue to keep green leaves during the mid-fall frosts. But these are not Hardy Chicago and not the same plant type every year. I have to use scissors to cut the leaves off to store them along with the other dormant plants.

shellie

Yes it is a fruit trees called Chicago Hardy. They produce delicious sweet figs in summer. My winter gets cold and I have to give them protection from the freezing weather. In the past I carried them to the Garage which was a back breaking job. This year I made a wooden frames around the raised beds where the pots are and I am covering the entire beds by a plastic cover which they use in building Green houses. So basically I am making home made green house if you want to call that. When the sun hits the plastic it is designed to let heat in and protect about 80% of it at night Also the plastic is clear so it allows the lights in. I am not an expert on that but that what the company which sold me the plastic cover claimed.

Foolish, I think that you do not have yet tested the system of "raised cold greenhouse", but I think that you will have few problem...

The best system is on the garage in contact to the ground and covered by a "tapee" full of leaves, envelloped in burlaps.

The plastic greenhouse do not have sufficient heat content to maintain a temperature different from the outside in case of more than two days without sun. To have sun on the plastic is not positive; in warm sunny days may be that internal temp goes up to 45 F, and may partly awake the fig, which is very negative.

Shellie: in Missouri Z6a is possible to cultivate fig plants outside with some possibility.

The way is to cultivate the young plants in large pots the first years, recovering them in garage in winter.

When plants become a bit older is possible to plant outside on ground, considering that, if possible, the plants have to be planted in a warmer conner of the site (less cold winds), the first years also if protected by leaves and hay, may be the plant is died till ground but may be it resprouts.

However also if cultivated in pot, as by Foolish is a good idea for have few good fruits. The ground have to be DRY and well drained in vegetation seasons.

About Foolish; Shellie there's nothing or quite that is impossible; I've fig friends in Canada, Sweden, and Northern England, and of course in northern US as, as example, in the windy Chicago IL.