Winter Care for Banana Trees
Banana trees are a fun way to add a tropical flare to your garden, even if you don't live in the tropics!
Your question prompted me to look through my Stokes Tropicals catalogue to refresh my memory about these unique plants. I was impressed at the array of sizes, forms and leaf colors. And several varieties were cold tolerant to zone 7. I even found one called Musa Basjoo that, with a protective layer of mulch, is cold tolerant down to -24 degrees F. Now this is not to say that they will stay evergreen in these cooler climates. After the first hard freeze the plant will die down to the roots and then rebound with new growth next spring.
If you live in a zone 7 (0 to 10 degrees F) to zone 5 (-20 to -10 degrees F) and choose to leave your cold tolerant banana plants in the ground over winter, it is important to cover the rhizome (underground roots) with at least 1 foot of mulch. You may also find it helpful to top the mulch with a layer of plastic for extra insulation. If you add the plastic, be sure to remove it or replace it with a filter fabric in the early spring. You see, spring temperatures combined with the mulch and the plastic can create enough warmth that the tree may put out new growth, which might get zapped by a late frost.
Another alternative is to store your banana trees indoors during the winter. Before the first frost dig up the plant and gently remove any excess soil and then cut the leaves back close to the base of the trunk. You will be left with something that looks like a pole with roots.
Place the plant in a container filled with moist sand and store it in an area that will not drop below 50 degrees F. Stop watering or fertilizing and allow the plant to go dormant.
In the spring, after the last frost date in your area, you can plant your banana tree in the garden again.
If your banana trees are growing in containers and they are a manageable size you can move them indoors and treat them as houseplants. Just place them in a warm, sunny location, stop fertilizing and only water the plants as needed.