I see posts about wintering figs in barns ect where temps get to 20 degrees ,what I am not clear on is if the root balls can take this temp in the planters? how cold can a wrapped standing fig get and how do people in zones 4 and 5 protect inground trees. Thanks,Rex

When relatives were alive here in Chicago by Midway airport there trees were buried.
Me now little further south i keep them in the attached garage in there containers .
Mine see garage temps in the teens for a spell each winter as i do not heat the garage.
Yeah them containers feel pretty solid i cracked one few years back when i kicked it on purpose.