Gardening Vegetables

Grow Your Own Kalettes

What do you get when you cross Brussels sprouts with curly kale? Kalettes!

Photo: Euronaut, Wikimedia Commons

By Larry Hodgson

Kalettes. They’ve been around for a few years now, but suddenly seemed to have hit their stride last fall, at least where I live, when they were everywhere in local supermarkets in November. Little flowerlike rosettes of crinkly green kale with purple highlights, about 2 in (5 cm) in diameter, cute as a button and just what you need for a tiny personal salad or a side dish.

Bag of kalettes from a supermarket.
Kalettes were widely available last fall and that may become the norm. Photo: costcuisine.com

I received several emails about them. In general, people either wanted to know what they were or how to grow your own, so let’s look at both aspects.

What Is a Kalette?

The name Kalette® is actually a registered name with Tozer Seeds of Great Britain.

Comparison of Brussels sprouts, kalettes and curly kale.
Kalettes are intermediary between their two parents: Brussels sprouts and the curly kales. Photo: modernfarmer.com

Some 20 years ago, hybridizers working for Tozer decided to cross Brussels sprouts with curly kale. Both are variants of cabbage (Brassica oleracea), so that cross presented no problem*. Then about a decade was invested in further crosses and selections, eventually developing the kalette, a tiny kale borne on the tall, thick, upright stem of the large-leaved mother plant, exactly as Brussels sprouts are produced. The difference is that, instead of a little round button of a cabbage (Brussels sprout), you end up with a leafy little kale: the kalette.

*Kalettes were developed using traditional breeding techniques: taking the pollen from a flower of one variety and depositing it on the flower of a different variety. So no, they are not GMOs!

Well, at least they’re called kalettes now. When the first ones were launched in 2010, Tozer originally called them Flower Sprouts, and I guess they do look a bit like purple and green flowers. And Lollipops when they were introduced into the United States. But the name kalette seems to be the one the public preferred and it has become the common name for this new vegetable.

Kalettes sautéed in butter and garlic.
Kalettes sautéed in butter and garlic. Photo: Tanyak Design, depositphotos

Kalettes are sweeter than either Brussels sprouts or kale, with a nutty taste, and can be served in unlimited ways: as dipping material, raw, steamed, sautéed, microwaved, roasted, boiled, etc. Anything you might want to do with cabbage or kale would suit them fine. There is even a website offering specific kalette recipes: www.kalettes.co.uk.

And, like other cruciferous vegetables, kalettes are an excellent source of nutrients: particularly vitamin K, vitamin C, folate, fibre and carotenoids, not to mention antioxydants.

Kalettes are a fall or winter crop, so you’ll likely find kalettes as fresh vegetables in the Northern Hemisphere from November through April.

Can You Grow Your Own Kalettes?

Of course, and it’s not even that difficult.

Kalette seedlings
In most cases, kalettes are sown indoors, then transplanted to the garden. Photo: valerypetr, depositphotos

You can sow kalettes outdoors in mild climates, once the soil starts warming up early in the spring, but in temperate ones, it’s better to start them indoors to get a head start on the season, as they are very slow to mature.

Kalettes are best grown with a fall or winter harvest in mind, as they produce and taste better in cool weather. Given the plant’s slow maturation, you’ll need to start them in the spring.

Since each plant produces prolifically, you won’t need many plants: maybe 4 or 5 for the average family.

So, starting 4 to 6 weeks before your local last frost date, sow the seeds about ¼ in (6 mm) deep in a small pot or the cell of a plug tray* using sowing mix that you have lightly premoistened. Then cover the seeds with mix and water lightly.

*It’s always best to sow 2 or 3 seeds per 3-inch (7.5 cm) pot, as germination is never 100%. Since you only want one plant per pot, simply cut back any excess plants later, keeping only the strongest one.

Place your seed trays in bright light, but not yet full sun, covering with a clear plastic bag or dome to maintain good humidity. Germination can occur at temperatures from 50 to 85°F (10 to 30°C) and usually takes 7 to 10 days.

After germination, gradually remove the covering. Now is the time to move the tray to full sun or under an intense plant light. Keep evenly moist and give the pots a quarter turn in the same direction every few days to keep them upright, otherwise they’ll lean towards the light.

As temperatures warm up outdoors and the risk of frost diminishes, acclimatize the seedlings to outdoor conditions over a week or so, getting them used to shade, then partial shade, then sun. Don’t hesitate to bring them back indoors on really cold nights.

Removing kalette plants from their plug tray for planting.
In early summer, plant the seedlings into the garden. Photo: bonnieplants.com

When the plants have 6 to 8 leaves, plant out in full sun. This will likely be in late May or June.

Kalettes prefer a pH a bit on the alkaline side—6.5 to 7.5—, although 6.0 is acceptable. A rich, well-drained soil is best. You can add compost, well-decomposed manure or a slow-release organic fertilizer to the soil. There is no need to add mycorrhizal fungi: they “don’t take” on plants in the cabbage family.

Woman holding a stem of kalettes.
The plants are tall and may need staking. Photo: fruitnet.com

Space the plants about 18 to 24 in (45 to 60 cm) apart. They may look a bit forlorn at first, but you’ll see: they grow quickly and soon fill in any empty space. Do firm the soil well around the plants, as they have a limited root system, yet a heavy top and you don’t want the wind to push them over. Either that, or stake your plants as they start to grow tall.

Mulch to help keep the soil cooler and moister. Water as needed throughout the growing season to avoid drought stress. And it’s always best to cover the plants with an insect barrier (floating row cover) starting immediately after planting to keep their enemies at bay, at least for the first half of the season.

The plant grows strong and tall, to about 30 to 36 in (75 to 90 cm), looking very much like a curly kale with well-spaced leaves … except that buds start to form at the leaf axils as the plant matures, especially with the return of cooler temperatures.

To stimulate maturation for a more concentrated harvest, cut off the tip of the plant (you can eat it!) when the rosettes near the base of the plant are about ½ to ¾ in (1 to 2 cm) in diameter. Don’t do this if you prefer a prolonged harvest, a few rosettes at a time.

Mature kalette plant with leaves on top and kalettes along the stem.
Kalettes are best harvested in the fall, after the first frosts. Photo: Crampton’s Market

It’s after the plants have been exposed to cool temperatures, and preferably a bit of frost, that they take on their best flavor. In mild climates (USDA hardiness zones 8 to 9), you can harvest them all winter. Indeed, in a mild enough climate and if conditions are good, the stems may even produce a second crop if you leave them standing! In colder climates, though, bring in the kalettes in before the ground freezes solid.

Storage

Individual kalettes ready for storage.
You can store kalettes in a root cellar or freeze their leaves. Photo: Digifuture, depositphotos

Besides eating them fresh and making kalette sauerkraut, you can also keep kalettes for a week or so in the refrigerator and from 4 to 6 weeks in a root cellar at 36°F (2° C) with 95–98% relative humidity And you can also remove the leaves from the rosettes and freeze them for future use. To do so, blanche them first in boiling water, then plunge them into ice water to stop the cooking process, drain well, then pat dry. Place the leaves onto a baking sheet to freeze, then transfer to an airtight bag to store in the freezer.

Can I Harvest Seed From My Kalettes for Future Years?

Not really.

Kalette seed capsules and seeds. Photo: ourochreway.com

If the plant survives the winter and blooms the second year (it is a biennial, after all), it will produce seeds, even lots of seeds, but the seeds won’t be true to type. The F2 (second) generation will give plants with a mix of traits, some more like Brussels sprouts, some more like kale, some indeed very close to kalettes and others quite different yet. You can experiment if you want, but otherwise I wouldn’t waste too much valuable garden space on resown seeds.

What you can do though is to store unused seeds for use in future years. If they’re kept cool and dry, they’ll usually remain viable for about 5 years.

Where to Obtain Seeds?

Seed is available from many sources: Johnny’s Selected Seeds, Territorial Seed Company and Harris Seeds in the USA, Stokes Seeds and West Coast Seeds in Canada, Sarah Raven and Chiltern Seeds in the United Kingdom, etc. I haven’t been seeing kalette seeds in local garden centers yet, at least not in my area.

Be forewarned, though, that since kalettes are F1 hybrids and therefore seed has to be produced by physically crossing two different parents, that extra manipulation means the seeds are going to be more expensive than those of most non-hybrid kales and Brussels sprouts.

Kalette ‘Autumn Star’.
Kalette ‘Autumn Star’. Photo: sarahraven.com

There are 3 cultivars available. In short-season climates, stick with ‘Autumn Star’: with a 110-day maturity after planting out, yet great frost tolerance, it will have time to mature. ‘Snowdrop’ (140 days) is the best choice for long-season climates where it will produce all winter. In between the two is ‘Mistletoe’ (also marketed as ‘Christmas Rose’) (125 days), for climates where harvesting remains possible up to the end of December. Some companies offer a mix of all three.


Now you know a lot more about kalettes. Maybe you should try them in your garden this summer!

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, laidbackgardener.blog will continue its mission of demystifying gardening and making it more accessible to all.

6 comments on “Grow Your Own Kalettes

  1. Grew them for the first time last year, amazing growth tallest plant 6foot 2inches ,nobody told me about their height fortunately you have to stake every thing hear in north cornwall either that or your sharing it with the folk across the border. Purchased the seed from D.T.Brown

  2. marianwhit

    Thanks! I ALWAYS fall into the trap of planting my brassicas too close together. In NS, I recommend a row cover.

  3. Oh goodness! Well, although I am no fan of these weird developments and fads, and I am none too keen on kale, I do happen to like these. A neighbor gave me a bunch two autumns ago. I cooked and ate them just to make them go away. They really were like both parents, so I enjoyed them as Brussels sprouts with the texture of kale. I still prefer Brussels sprouts, but would not decline on these if a neighbor happens to share them again. I think that they are a nice alternative for those who dislike Brussels sprouts like I dislike kale.

  4. These look like fun. Will have to try some this year

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