I have been in touch with a Pennsylvania fig enthusiast named Will. He told me that the harsh winter of 2013/2014 took a heavy toll on fig trees in his area. Trees without very good protection were killed right back to the ground.
Will grows upright, in-ground fig plants. His protected tree did NOT die.
He sent me the pictures below of his clever system of protecting in-ground fig trees.
Overwintering fig trees in cold climates, with a bit of creativity, is possible. Thanks, Will, for sharing!
Will says: “The system incorporates a 40-watt incandescent light bulb suspended in a 4-ft. tin exhaust tube (3-inch diameter). The light is turned on only when the temperature goes below 15°F (-9°C) and turned off when the temperature gets above 15°F (-9°C).”
Will says: “I have protected the tree under an inverted tomato cage.” Will says:“The 40-watt bulb is tied to the tree which is tied and wrapped in burlap. The tube acts as a heat column beside the tree. Then, both are placed inside the inverted tomato cage and wrapped in a Planket (which is waterproof but breathable).”
Will says: “The heat tube must be turned off when nighttime temps rise above 15°F (-9°C). I use both 25-Watt and 40-Watt bulbs depending on the size of the tree.