Putting Bananas To Bed For Zone 8b Winter

I have been growing bananas for several years now. Mainly, I grow Gros Michel which is a full sized, fruiting, antique banana. The first few winters: I brought them into my front entry that could accommodate the 12+ foot bananas and kept them in pots with grow lights on them.

They didn’t like it. They got spindly and broke easily. Plus, they took up a lot of room and I had to spray them for spidermites frequently (which burned their tender leaves.) The following growing advice is for zone 8 and above, and how to get bananas through winters outdoors in areas with few freezes.

Then I had a year where I wasn’t going to be home for Christmas, so I put a few of the banana pups in pots and put them in the garage and hoped for the best. I watered them lightly and infrequently. They did alright. They were still spindly and weak, plus they died back to their pseudostem until I put them back outside. I also lost the ones that I put in the garage without pots or soil.

If you are trying to get bananas to make it through winter outdoors: lay down the stems as flat as you can, chop off the leaves down to the pseudostems and water the planting area two or three days before your freeze. Watering helps with heat exchange. Water actually gives off heat in the process of freezing.

I don’t add water to the huge amount of straw that I put in there. I will use the straw as mulch in spring. I also don’t cover and uncover the bananas. They won’t grow under 50 degrees, and I haven’t had issues with light exposure, so I cover them and leave that arrangement for the three months that we have random freezes.

Then last year we had that crazy snow (and super cold weather) blow through. That was not something that usually happens down here, for sure. But, I had laid the bananas down for a previous short freeze. When the week long super freeze (with several inches of snow and a low of -16°F) came through: my bananas were already protected. I didn’t expect them to survive. But even with just the straw and plastic sheeting, the rootball made it.

I laid my bananas down in the raised bed I was growing them in. To do this: cut a large horseshoe shape around the banana rootball, leaving the roots attached on the side the banana will lay down on. This keeps the banana from drying out and loosens the base of the rootball, so you can push it over. But be careful. Once they start to fall you need to be out of the way.

Bananas are monocots (as opposed to dicots.) So, they are related to grass and other unbranching plants. Because bananas are monocots: they have pseudostems. They are actually layers of leaf sheaths and not an actual tree trunk. This is why they don’t make it through freezes. They’re just a big bunch of tropical, herbaceous, leaves.

Full sized banana pseudostems are also full of gallons and gallons of water. So they are very, very heavy. Make sure you have help if you are trying to lay them down (or at least someone who can call emergency services, if it falls on you!)

Of all of the common vegetables I can think of, banana stalks are most like giant celery or rhubarb stems. All three are watery, they break easily and they have stringy support tissue in the stalks. If you cut banana pseudostems (or celery) they are both really stringy. The stringy tissue in banana stems is easily chopped through with a sharp machete, but the stem will hang up and shred if you use a saw on it. If you want to cut back banana leaves: get a sharp machete.

I do shorten the pseudostems, with a folding saw, if the pseudostem doesn’t fit in the raised bed. Be careful when you do this though because if you cut through the flower stalk you will not get fruit, even if the stem survives. You won’t know that you’ve done this until you have finished cutting off the stem ends. I recommend cutting the pseudostems only if you won’t be able to save the ends from a freeze.

The fibrous roots are very easy to cut through with a shovel. But, if you leave dead banana rootballs in the ground they harden up like a brick. Our trash service won’t take them once they harden. If our trash service has a banana root policy, I am obviously not the only person down here trying to grow them. Cut the rootballs into quarters (if they freeze back and die), and dispose of the roots before they harden.

Originally when I saved the bananas in place outdoors: I cut back the leaves on the two, 14 foot, stems that I laid down. Then I covered the stems with straw. I put a plastic tarp over everything and hoped for the best. The -16 degree weather froze the stems back, but the root balls survived. (I was honestly amazed at that!) The fact that the rootball made it through that kind of cold gives me hope for saving the stem in our normal winters.

For older banana varieties to fruit: they need two years of growth. So, if I ever want to eat a Gros Michel banana: I need to get the pseudostems through the winter, in a robust fashion, which I have not been able to do… yet. And, no, I could not move the giant plant and rootball, even a few inches, nevermind getting them out of the garden and into the garage. My husband is strong enough to rock the rootball but even he can’t move it, with help or not.

Since the cold snap last year was very unusual, I am hoping laying down the bananas, putting mini incandescent Christmas lights on the stems and roots, covering everything with straw and then tarping it, will get the stems to survive.

This is a venture I usually file in my experimental, tropical fruit growing file that I call: a “defiance garden”. It’s very possible that I will only get the rootball to survive again. In that case I will revert to saving young side sprouts (pups) and cut off the stems to the ground and bring the pups inside. This is a lot of work in case I just get the exact result as I did last year when I didn’t use the lights.

I started growing, what I call “defiance gardens”, decades ago in Colorado’s front range.  Our county gardening site said it was too cold and too short a season for beefsteak tomatoes or for melons. I successfully grew both. I planted short season melons with a bottle of water beside them to retain heat at night. The tomatoes were vastly more complex to get them to ripen. It included creating a 5 foot tall, mini greenhouse, out of clear plastic sheeting and wood and eventually pulling, then hanging the plants upside down, in the garage. But, I did it. However, it took lots and lots of extra work. I learned my lesson about respecting my grow zone and to not try to grow a defiance garden on a large scale!

Even with years of experience in my grow zone, I always have something going on that is an attempt at getting around the limits of my area’s average temperatures. I have labeled this annual, huge amount of extra work as a “defiance garden” because I am defying my local limits and telling mother nature that she can’t control me so easily! I have also had a few disasters trying to do this. So, it doesn’t always work out. However, I’ve always learned something from my experiments, so I keep trying out new ideas annually.

There are native (and tropical) fruits that I have tried to grow, and I ended up with huge failures. Our heat is too hot, and our winters are just a little bit too cold. But, sometimes it’s just fun to run with a theory that I’ve come up with. It definitely gives me something to do outside in winter, when I’d usually be indoors. Plus: if I figure out a way to get something unusual through our short freezes in South Texas, I get to laugh at what is generally regarded as rigid limitations. But, attempting a defiance garden is always a whole lot of work.

You may wonder why the heck I’m even trying this. I can only explain these insane attempts to alter my grow zone (or soil pH, or moisture. You name it: I’ve tried to extend whatever the limits are.) because having grown my own fruit: grocery store produce can’t hold a candle to freshly grown, completely ripe fruit. I have had some of the most incredible fruit from my own garden (like pineapple, non astringent persimmons, figs, blueberries, raspberries and strawberries). Fruit that redefined the way I expect fruit to taste.

I am waiting for a load of perfect bananas. (Ones like I tried on the roadside in Hawaii.) I have a great growing season for them (250 days.) The only problem is our rare freezes in our three month winter. Our temperatures in winter are usually in the 50s to the 70s (°F) with a day or two of freezes per month. If I can fight back on those few freezes, the bananas may make it, and I’ll get fruit. Otherwise, I’ll grow the Gros Michel for its beauty, and try my luck focusing on the 9 month bananas.

I don’t have a greenhouse. So laying things down and covering them is the best I can do. Plus, this will be warmer than I could reasonably keep a greenhouse. I tried running C9 Christmas lights (the big bulbed ones) and they get way too hot and would more than likely cook the plants. If I had a greenhouse I might use the C9s then, but not for this experiment where the bulbs touch the plants and where I’m using plastic sheeting.

So, I’m using the mini Christmas lights. These need to be incandescent bulbs and not LED bulbs. Part of the reason LEDs are cheaper to run is: that they don’t waste heat when lit. Light and heat are closely related. “About 90% of the energy consumed by an incandescent light goes into generating heat, whereas LED lights create a low amount of heat. This is due to the way that LED lights are created.” (link)

This is why you need incandescent bulbs. For this purpose: you want the bulbs to release heat. To make sure you have the right bulbs, look for filaments and supports (these look like tiny wires) inside each bulb and a glass end with inert gas in it. LED lights have diodes. That means no filaments and usually a solid plastic tip that lights up. I found some incandescent light strings at Hobby Lobby. Walmart also carries these.

FYI I have not been able to find a lot of instructions for doing this online, so this may be the only post on the internet with this information. A lot of people reference using bulbs, but I don’t think they lay down what they’re growing and then put straw and a tarp over it. They also don’t tell you exactly what they did, with pictures, to help you recreate it.

I know in Chicago: people lay down fig trees and cover them with soil for the winter, so I know I can’t be the only one who has added different insulation (straw) and lights. But, I honestly couldn’t find any decent instructions for this other than my own.

They sell freeze sensitive electrical plugs like these: https://amzn.to/32Jb5zV This type of plug turns on at certain temperatures. Make sure you understand what those temperatures are. I’m not using one, simply because I’m home all of the time and I keep up with weather predictions. But they’d be handy to have.

They also sell soil heating cables https://amzn.to/3mT96jl , if you are interested in upping your game. I looked into them, but the price to heat my large beds just kept going up, as I calculated what I’d need and considered the length of time those seem to last. I may try them next year, but honestly I’m looking for the cheapest solution and they were not it. Plus, this arrangement, (minus the string lights) got my banana’s rootball through crazy cold. I am hoping this new addition is enough to keep the stem from freezing.

So, winter 2022: I have the bananas wrapped in mini Christmas lights and covered in layers of straw. I put a large plastic tarp over the bed. Tonight we’re in the mid 30s. The next two evening’s lows are in the upper 20s. Then we’re back into lows in the 50s. Hopefully, my banana experiment is going to work out.

I made sure to bring a couple of young bananas inside, so that even if a freeze kills what is outside: I still have one of each variety to put out this spring.

Wish me and my banana experiment luck! We will probably need it. Let me know in the comments below if you have a habit of growing defiance gardens or if you have any advice about overwintering tropical fruits outdoors.