How to Grow Kale
Kale is easy to grow, easy to overwinter, easy to preserve, and absolutely delicious! Oh, and it’s just a pretty plant as well. If there’s one plant I would recommend for every garden, it would be kale.
And it’s not just me. In Barbara Damrosch and Eliot Coleman’s wonderful book The Four Season Farm Gardener’s Cookbook*, they state the following:
“Kale is a true survival food — such a traditional mainstay in Scotland that the word kail stands in for dinner itself, and kail-yard for a garden.”The Four Season Farm Gardener’s Cookbook, p. 129
How to Plant Kale
While you can definitely find kale transplants in most nurseries and garden centers during planting season, it’s so easy to grow kale from seed, and so much more cost-effective, that this is my recommended method. Plus, rather than the one or two kale varieties offered in most garden centers, you can experiment with different types. I’ve grown everything from dwarf curly kales to deep purple kales that looked almost too pretty to eat.
Kale can either be started indoors under lights or near a bright window, or sown directly in your garden. If you choose to direct-sow, it’s best to wait until your soil has warmed a bit, since the seeds need warmth to germinate. For the earliest harvest, sow them indoors under lights about 6 to 8 weeks before your last frost date.
The seedlings can be hardened off and planted into your garden a couple weeks before last frost as long as your garden isn’t under snow and the soil is workable. I like to install a low tunnel over the bed where I plant my early kale. This helps my little plants off to a good start, but also protects them from the rabbits and deer who are absolutely ravenous for anything tender and green in early spring.
While spring-grown kale is delicious, it’s well worth starting a fall crop in mid to late summer. The leaves are even more tender and flavorful after a frost, and, if they’re a bit of cover, they’ll likely survive through most of the winter. Even unprotected kale will still be good to eat right up until the most frigid part of winter.
Sow seeds or set transplants about 12 inches apart, but this varies by variety. Some of the larger kales, such as lacinato, should be placed 18-24 inches apart. If you’re planting seeds, plant them about 1/4 inch deep. If you’re setting out transplants, plant them as deeply as they were in the original cell pack or pot.
How to Grow Kale in Your Garden
Kale is fairly easy to grow. It needs fertile, well-drained soil, and at least 6 hours of sunlight per day. It should be planted 12 to 24 inches apart, depending on which variety you’re growing. Water regularly to keep the plant producing new leaves. A top-dressing of compost or composted manure every few weeks (once a month or so) will definitely benefit these nitrogen-loving plants.
Unless you live in a very hot climate, the kale you plant in spring will generally keep growing all season long and into winter, but I like to make a second planting in late summer to have even more kale to harvest throughout the winter.
How to Grow Kale in Containers
Kale is one of those vegetables that works wonderfully in containers. And the lovely thing about growing in containers is that you have the freedom of moving your plants around until you find a place where they thrive. Any container you choose to grow kale in should have drainage holes and be at least 8 inches deep.
You can plant one kale plant in a single pot, or a few if you have something larger like a deep windowbox or galvanized tub. The main thing, once you find the ideal spot for your container-planted kale, is to make sure to water regularly and fertilize with a weak organic fertilizer solution once per week throughout the growing season.
When it gets too cold in the garden, you can easily move your containers of kale to a covered or screened-in porch or high tunnel to keep it going well into the winter.
Kale Pests and Problems
These are those little green caterpillars, the larvae of the cabbage butterfly, that are the bane of every gardener who loves growing members of the cabbage family, including cabbage, broccoli, cauliflower, and, yes, kale.
If you only have a plant or two, your best bet will be to regularly inspect your plants, looking under the leaves and along the stems, especially if you notice that something seems to be nibbling on them. Pick the worms off and toss them into a dish of soapy water (or, if you have chickens, they absolutely LOVE them).
If you have a lot of kale planted and don’t have the time to check them all for worms, I love using row covers or insect barriers draped over my plants. You have to do this early in the season, before you start seeing the little white butterflies around. By draping and securing covers over any beds and containers you’re growing kale in, you prevent the butterflies from laying eggs on your plants, which will eventually hatch and grow into cabbage worms.
Root maggots burrow into the soil and tunnel into the roots of brassicas plants, eventually killing the plant over time. The best way to prevent this is an issue is… floating row covers or insect barriers.
Are we detecting a trend? To be honest, I grow all of my brassicas under lightweight row covers all season long. It just saves me a lot of effort and problems.
Cutworms can also be a problem. These are worms that usually strike at night, and the way you’ll know they were there is that your seedlings will look like they’ve been chopped by a tiny ax, lying on the soil, severed from the base and roots. If you have cutworm issues, it’s a good idea to make a ring out of either paper towel or toilet paper rolls, surrounding the stem, sinking part of the collar into the soil and keeping the rest at least an inch above the soil line.
If you’ve already had plants destroyed by cutworms, scratch up the soil around the fallen plants. The worms dig down during the day, not very deeply, and you’ll usually find the curled up little pests by disturbing the soil. Remove/kill them (or feed them to chickens or wild birds by setting them on a feeder) to cut down on the population.
How to Harvest Kale So It Will Keep Growing
If you want to keep your kale going all season long, you’ll want to be sure you’re harvesting correctly. Kale grows from the center of the plant, new leaves forming on the inside, older, larger leaves on the outside.
If you make sure that you’re only harvesting those larger, older leaves, the plant will continue producing new leaves at the center of the plant all season long. By the end of summer, the plants can start looking a bit funny, like kale palm trees, with tall bare stems where you’ve been harvesting, and a rosette of younger leaves at the top.
They’ll still taste perfect, though, and if this bothers you, it would be a good idea to plant some new kale in your garden every couple of weeks through late summer, so when the plants start looking too leggy for you, you can simply pull them out and you’ll have younger, less-leggy kale growing elsewhere in the garden.
If this appearance doesn’t bother you, you can just keep them growing as long as you want, harvesting well into fall and even winter.
Growing Kale in Winter
Kale you start in late summer can grow through the fall and into the winter. If you live in an area that doesn’t get a lot of snow, you can leave it just as it is, even uncovered, you can harvest well into the winter.
If you get a lot of snow, and really want to extend your kale harvesting season, season extenders are essential. A high tunnel will let you grow lots of kale and other cold-tolerant veggies all winter long. A low tunnel will protect a bed of kale wonderfully, and all you have to do is keep it watered until the soil freezes, then uncover and harvest whenever you want.
The plants will not be actively growing during this period, but growth will pick up again when things warm up in the spring. During winter, you’re just overwintering and harvesting.
Recommended Kale Varieties
I grow several types of kale here in my Michigan (zone 4) garden, and I love all of them, but I definitely have my favorites. This past year alone, I grew 5 varieties of kale, and would recommend any of them:
Lacinato*: this is also known as Tuscan kale or “dinosaur kale.” It grows up to around 2 feet tall, and the grayish/bluish leaves are deeply textured, and it has a mild, tender flavor that works really well in many dishes.
‘Red Russian’*: Soft-toned, deeply lobed green leaves with bright magenta veins and stems. This is just a pretty plant, and I’d grow it for that alone, but it’s also delicious. It doesn’t keep the magenta color at all during cooking, but if you pick the leaves young enough, they can be eaten raw in salads, and then you keep that striking color as well.
‘Dwarf Blue Curled’*: This is my favorite kale for overwintering in low tunnels or cold frames. These usually grow in low rosettes, around 8 inches tall. The leaves are bright green and very frilly/curly.
‘Mars Landing’: ‘Mars Landing’ has stunning, maroon-colored leaves that really stand out in the garden. It has a nicely mild flavor and grows around 12 inches tall. If you’re looking for a unique color in your vegetable garden, it’s definitely worth checking out.
‘Purple Moon’: Very, very dark purple leaves (though they turn green with cooking) makes this another absolute stunner for the vegetable garden. ‘Purple Moon’ grows around 12 to 18 inches tall, with a vase-shaped form. Like ‘Red Russian,’ you can get some of the gorgeous color of the leaves into your food by harvesting them when they’re young and tender and eating them raw in salads.
The two easiest ways to preserve kale are freezing and dehydrating. Kale can be canned, but only if you have a pressure canner. If you do, here are some good instructions for how to can kale in a pressure canner.
Freezing kale is straightforward enough. The only thing is that with kale, like many foods you’d like to freeze, you need to blanch them first. This retains its bright color and makes for a nicer texture.
Blanching kale is simple: wash and trim your kale. Bring a pot of water to a boil, and fill either a large bowl or pot or your kitchen sink with icy water. Once your water is at a full boil, put your kale in the water. Let it boil for 2 to 3 minutes. You’ll see that the color will become a bright, vibrant green. After 2-3 minutes, take your kale out of the boiling water and immediately place it in your icy water. This stops the cooking process, keeping the kale’s texture intact.
After your blanched kale has had its ice bath, dry the leaves off as much as you can. Water left on your kale will result in ice crystals, which can mess with the texture of your frozen kale. To dry, you can lay out your blanched kale leaves on some clean towels and pat them dry. A salad spinner also works well!
Once your kale is dry, simply put it in whatever containers you’d like to freeze it in. Plastic freezer containers work well, and so do zipper freezer bags. It’s a good idea to freeze the kale in the size of portions you’re likely to use in your cooking. I like to freeze mine in 2-cup portions, because this is a nice amount to add to many recipes, but you might want smaller or larger amounts depending on how you cook with it.
Right now, my favorite way to preserve kale is via dehydrating. It dehydrates beautifully, stores easily, and it’s so easy to use the dehydrated kale in any recipe I’d like.
If you have a food dehydrator (I have and LOVE this one) the instruction manual that came with it will have recommended drying times for all types of foods. You can also do a search for (your dehydrator brand/model) + (kale drying time) or something along those lines.
You can also dry kale in an oven, so that’s a good option for those who don’t have a dehydrator. It might take a little more babysitting, but it’s definitely do-able!
No matter which method you’re using, the first step is to wash and dry your kale. You want to make sure you don’t have any bruised, mushy leaves. You’ll also want to trim the stems and any thick veins out of them, because they won’t dry as quickly as the rest of the kale.
Once your kale is trimmed, washed, and dried, arrange it on the trays of your dehydrator and set it for the amount of time you need. Be sure to check it regularly — it might finish earlier than expected). If you’re drying in your oven, place your washed, dried kale leaves on a parchment or silicone-mat lined baking sheet, and put them in your oven on the lowest possible temperature, with your oven door cracked open. Check it every hour or so.
Perfectly-dehydrated kale should crumble when you crush it in your hand. If it’s flexible at all, it’s not dry enough for long-term dry storage. Either keep drying it longer, or store it in the freezer.
Storing dehydrated kale is very easy! You can crumble up the leaves and store them in airtight containers in a dark, dry place. Then, just add the dried kale to recipes whenever you want to up the nutrition. It’s easy to break off some of the dried kale and sprinkle it into recipes. And if you end up freezing your dried kale, it takes up less freezer space than regular frozen kale does.
I hope this post was helpful in both convincing you to grow more kale, and in answering any questions you might have about growing this nutritious, delicious, beautiful green.
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