Ever wish you could grow something delicious from outside your growing zone? Me too. I wanted to grow plants that don’t grow in North Florida… so I figured out how.
In this article, I’m going to share a few tips with you in this article so you can push your growing zone a little further south and squeeze in a few plants which would normally die during your winter.
Let’s face it… the tropics are the best place in the world for gardening. There are thousands of varieties of fruits and vegetables, many of which produce year round.
Many of our beloved favorite foods are from somewhere a lot closer to the Equator than most of our gardens. Have you had a cup of coffee or tea lately? A banana? A coconut and pineapple piná colada? And don’t forget spices! Vanilla, nutmeg, cinnamon, black pepper…
I have to stop. I’m getting depressed.
Fortunately, I have homegrown papaya, cassava, moringa, guavas and lemons that help me feel better. How did I pull off growing these crops in a place where temperatures drop into the teens overnight?
I did it with three easy methods. Let’s jump in.
Zone Pushing Tip #1: Thermal Mass Is Your Friend
What the heck does that mean? It means you can gain a growing zone or two by looking for trapped heat.
My favorite place in my yard is the 2′ strip along the south wall of my house. That’s my little slice of the tropics. There I grow two lemon trees, a key lime, bananas, chaya, papaya, Florida cranberry, guava, pineapples, Okinawan spinach and other totally tropical crops that would croak or freeze to the ground if they were even a few feet further from the wall.
See, a wall soaks up heat during the day and slowly radiates it back out again at night. Rocks, ponds, and the ocean do the same thing. That’s why you’ll see plants growing near the shore that would never survive the cold even a few miles further in.
Here’s how I keep my Key Lime tree going strong:
That tree is twice as big now as it is in that particular picture, but I’m too lazy to go outside and take a photo right now. Suffice it to say: if you have a south wall, or even a south-facing cliff or hill, take advantage of it. Key limes will freeze at 32 degrees, making them one of the least cold-hardy citrus. There have been 12 degree nights and the tree sailed through with only a touch of frost damage on a few branches and leaves that stuck out outside the protection of the wall. I keep pruning and tying the tree back to ensure it stays growing happily. The method is called “espalier,” which is French for “a total pain in the neck way to grow a tree, but it satisfies your inner control freak.” I get limes (and lemons from other trees), so I don’t complain. It works!
If you’re in, say, zone 4 or 5… you won’t be able to grow a lime tree this way, but you’re likely to pull off something that would normally only survive in zone 6 or 7 on south. Ever want to try growing Japanese persimmons or figs? Here’s your chance. Note: the overhang of your roof is a big help, too. The larger the overhang, the more protection you get from the chill of space above.
Zone Pushing Tip #2: Nestle Your Crops In The Bosom Of Mother Earth
Yep. We’re talking root cellar time.
I like growing cassava. In fact, I have a little (very little) side business of selling cassava cuttings to folks that want to grow this amazing staple. Yet it doesn’t like the frost. Here in North Florida, I grow them in full exposure out in the field. In the winter, they freeze to the ground, then grow back again in the spring. In the second year, I harvest roots. Here’s the problem: if you want to plant new beds of cassava, you need chunks of cassava cane to stick in the ground. That’s where new baby cassavas come from (unless you’re in an area where the rare Cassava Stork makes deliveries). If your plants freeze to the ground in winter, you have nothing to plant in the spring… and have to wait until mid-summer to get canes that are big enough to plant out. That’s pretty late and will delay your harvest significantly.
Therefore, I use the ground as a way to keep my canes in stasis through the cold months. Like so:
That’s a 5′ deep pit filled with stem chunks. After I put them in there, I throw straw on top, then a tarp over that. They keep quite happily thanks to the radiant heat of the ground, ensuring that I have a steady supply of good planting material for both my customers and my spring gardens.
You can use this trick with more than cassava. I knew a fellow in Tennessee who grew a banana tree in his front yard. Every year he’d dig that tree up in the fall, carefully wrap up the plant in burlap, then lay it in the earth beneath his house until spring… when he’d plant it again. It was a lot of work, sure… but it was insanely cool that he had a banana tree growing way out of its range. A pit like this (or a nicer root cellar) can keep a lot of things going that wouldn’t live otherwise.
Zone Pushing Tip #3: When All Else Fails, Wrap ’em Like Mummies
I like to grow moringa. They’re one of the healthiest plants you can eat, plus they’ve got medical benefits and can even be used as fertilizer for other plants. The first year I grew them, however, they got totally roasted by frost. Most gardeners I know in this area who grow moringa just shrug and say, “wait until spring… they come back from the roots.” This is true, but that wasn’t enough for me. I want maximum yields – and healthy, vigorous trees. Since moringa can stand a lot of pruning, I simply cut the tree trunks at 4′ tall, then put a ring of fencing around them and stuff that ring with straw, protecting the trunk from the winter extremes. Check it out:
You’d never know it, but that’s my “hedge” of moringa. They stay that way from November until after our last frost in March with no ill effects. As soon as I un-stuff them, they explode into new growth, bearing plenty of leaves before anyone else’s do. It also keeps the trees from dying during a really tough frost. That happens on occasion if you simply trust the tree roots to be fine while letting the tops get killed. I don’t want to take that risk… and my yield of leaves is pretty awesome this way too.
If there’s some tree that doesn’t exactly grow where you are… why not try wrapping it with straw like I do with my moringas? Chances are, you’ll have success.
Whatever you do… don’t give up. These are only three methods. I didn’t even talk about greenhouses, large pots on casters, Christmas lights, sheets, barrels of water on the north side of a plant, etc. Maybe in another post.
For now… go take a look around your yard and see if there’s a way you can stretch things. The fresh fruit, vegetables and roots are worth it. Plus, you can pretend you’re in the tropics.
Key lime pie, anyone?