Banana plants (Musa and Ensete genera) are tropical and subtropical foliage plants known for their dramatic, rapid growth. Many gardeners in temperate regions outside their typical hardiness zones (generally Zone 9 and warmer) choose to cultivate them as ornamental features. Since these plants cannot survive prolonged freezing temperatures, winterizing is necessary to protect the underground corm or rhizome. The protection method depends on the banana variety, the plant’s size, and the severity of the expected cold weather.
Essential Preparation Before Winter
The first step in preparing a banana plant for winter is encouraging natural dormancy. As autumn progresses, gradually reduce watering frequency to allow the soil to dry out somewhat. This reduction in moisture discourages root rot during storage and signals the end of the active growing season.
Wait until the first light frost naturally causes the large, delicate leaves to wilt and blacken. The cold damage allows the plant to naturally draw nutrients back into the rhizome, conserving energy for the following season. Once the foliage is visibly damaged by frost, the large pseudostem must be cut down. For plants that will be dug up and stored, the stem can be reduced to a manageable height of about one to two feet.
Make the initial cut using a sharp, sanitized saw or knife. Allow the cut stem to weep for a few days to drain excess water from the plant’s core. This drainage prevents fungal infections and rot during the dormant period. Once the stem has dried slightly, the plant is ready for in-ground insulation or indoor storage.
Insulating Plants Left In the Ground
For hardy varieties like Musa basjoo or plants in regions with mild, short-lived freezes, the rhizome can remain in situ with proper insulation. After cutting the pseudostem down to three or four feet, construct a protective cylinder or cage around the remaining trunk. Use hardware cloth, chicken wire, or similar mesh material to create a barrier extending at least a foot past the stem’s diameter.
Pack the space inside this structure densely with dry, loose insulating material such as straw, shredded leaves, or wood shavings. This packing material must remain dry throughout the winter, as wet material promotes rot. This thick insulation layer helps maintain a relatively stable temperature around the rhizome, shielding it from deep-freezing.
The final measure is to cap the top of the cage with a waterproof covering, such as a plastic sheet or small tarp. This covering prevents rainwater or snowmelt from saturating the insulating material and the dormant pseudostem. Secure the cap firmly to prevent wind damage, ensuring the structure remains dry until spring.
Storing Dormant Plants Indoors
Tender banana varieties or container-grown plants must be fully removed from the ground and stored indoors. After the initial cut-back and drying period, carefully dig up the plant, extracting the main corm and as much of the root system as possible. For bare-root storage, gently shake off excess soil. Lay the plant on its side in a protected area for several days to cure and drain further.
The ideal storage environment is a cool, dark, and frost-free location, such as an unheated basement, root cellar, or insulated garage. Maintain temperatures consistently between 40 and 55 degrees Fahrenheit (4 to 13 degrees Celsius). In this temperature range, the plant remains truly dormant, requiring no light or water until spring.
Smaller offsets, or “pups,” can be potted in slightly moist, sterile soil and stored in the same cool conditions. Larger, bare-root rhizomes can be placed directly on a bed of peat moss or wrapped in burlap. Ensure air circulation to prevent mold growth. Regular inspection is necessary to check for desiccation or pest activity, but avoid watering unless the corm appears excessively shriveled.
Transitioning Back to Spring Growth
Timing the spring awakening should occur only after the last hard frost date has reliably passed in the local area. For in-ground plants, completely remove the waterproof cap and all insulating material to prevent overheating and allow air circulation. Cut the remaining pseudostem down to the point where the tissue is firm and healthy, indicated by a lack of mushiness or discoloration.
Stored plants, whether bare-root or in containers, require gradual reintroduction to warmth and light, known as hardening off. First, move them to a sheltered, semi-shady spot outdoors for a few hours daily. Slowly increase sun exposure over one to two weeks. This prevents the shock of immediate bright light, which can scorch tender new foliage.
Once planted back into the garden or moved fully outdoors, the dormant rhizome needs its first significant watering to stimulate new growth. A light application of a balanced, slow-release fertilizer can also be incorporated into the soil. New leaves will begin to emerge from the center of the corm, quickly accelerating the plant back into its vigorous summer growth cycle.