Most species in the fig (Ficus) family thrive in temperate and warm climates and do not tolerate sub-freezing temperatures well. Fruiting fig trees need roughly 100 hours of temperatures between 32 and 45 degrees F each year in the winter, during dormancy, to set their buds. Mature fig trees that have been hardened by previous years of cold temperatures can survive periods at 15 degrees F, but tender new growth does not have the same tolerance and will be killed, according to Texas A&M University. Timing and modification of care will help prepare the tree for winter. When cold damage does occur, the fig will readily regenerate itself, typically as a smaller shrub. Fig trees grown in climates without hard frosts rarely require winterizing measures.
Reduce the amount of water you give your fig tree, beginning in early fall, to slow growth and trigger dormancy. Water deeply and less frequently, just enough to keep the soil from drying out entirely and to keep the tree from wilting.
Halt application of fertilizers by early to mid-summer to encourage dormancy and ensure than no new growth, which is more susceptible to cold damage, is present on the tree when temperatures plummet.
Grow your fig trees planted up against the southern exposure of an insulated building to create a warmer micro-climate and limit the cold damage to the tree tissues.
Mulch around the lower trunk and crown of your fig tree with an organic insulating material such as straw or wood shavings. Pile the material up 3 to 6 inches so that the crown of the fig is covered by a few inches of mulch. Remove the mulch from the crown in spring after the last hard frost has passed and the ground soil is thawed and warm.