Plant a cold-tolerant variety of a tropical fruit in a protected location, such as on the south side of your house or garage. If eaves cover the planting area, they will help to protect the fruit from frost.
Grow your tropical fruit in a container that you can bring indoors for the winter if you prefer this method and have space in your house or greenhouse.
Mulch tropical fruit plants at least 4 inches thick in the fall to keep the soil as warm as possible. Use organic materials such as compost, leaf litter, straw, sawdust or wood chips and be sure to keep it at least 2 inches away from the base of your plant.
Cover your tropical fruit plant on nights when the temperature is forecast to drop below 32 degrees Fahrenheit. Use a blanket, tarp or plastic sheeting, but build a frame to keep the covering from touching your plant.
String Christmas lights through your tropical fruit plant in the fall and turn them on at dusk on cold nights. You might want to use incandescent lights instead. Hang at least one 100-watt bulb close to the top of each plant.
Spray your tropical fruit plant with an anti-transpirant spray before the onset of cold weather. Follow product instructions for correct application and be sure to repeat your application at the recommended intervals.