Posted by: ceara08 | March 24, 2009

Plant Profiles – Kale (Brassica oleracea)

Once again I have been looking at the stats for this blog and notice what people type in search engines to reach my blog. And today, I find in the stats that someone searched for “kale growing when spring “zone 4.”

So I thought I would assist in providing some information in case others are doing a web search.

The following is an excerpt from one of my gardening books, “Burpee: The Complete Vegetable & Herb Gardener – A Guide to Growing Your Garden Organically.” It’s a hardcover book, 438 pages, ISBN # 0-02-862005-4

A traditional Scottish story tells of a young doctor looking for a town in which to open his practice. “If you see kale growing in the gardens, move along,” he was advised. “They won’t be needing your services there.” Kale may not be a complete substitute for health insurance, but it is one of our most nutritious cultivated greens. It has slightly less iron than spinach does but three times the vitamin C, more vitamin A, more B vitamins, and more calcium, potassium, and protein.

Kale was grown by the Greeks and Romans, then traveled to northern Europe and Britain and, in the 16th century, on to North America with the French explorer Jacques Cartier.

Kale is sometimes called “the cabbage without a head.” It is indeed in the cabbage family, Brassica.

It can be grown pretty much everywhere except the warmest plant hardiness zones. Kale, however, prefers cooler weather, and its taste is improved when touched by a slight frost.

A few versions of Kale exist. Some with curly leaves, and some with smooth leaves. Some with red veins in the leaves, at times possibly almost purple.

Don’t confuse a Brassica Kale with the common name of “Sea Kale” which is really Crambe maritima, and grown completely different. Sea Kale is commonly grown, allowed to rest, and covered with a special “forcing” pot which is placed over it, with fresh stable manure stacked around the outside of the pot. The manure begins to decompose, providing heat for the plant. The forcing pot is topped with a lid and this blanches (turns white) the leaves and stems, producing a delicate lovely pale harvest which is then gently boiled and served with butter, Victorian style.

How to grow Kale

Kale likes full sun in early spring but prefers a bit of shade during the hottest, sunniest part of the growing season. It will push through the season and still be seen growing strong at the onset of winter.

It prefers rich, acidic soil and doesn’t like to be fertilized too much. Your best bet is to feed the soil, not the plant. What does that mean? Well, you amend the soil properly before you ever sow seeds or dig to plant pre-grown seedling plugs. This is accomplished by mixing in some well-rotted farmyard manure (horse, cow, sheep, rabbit, or chicken poo), perhaps some leaf mold (composted tree leaves), maybe some peat moss or coconut coir. What you need really depends on your soil type.

If you have mostly sandy soil (like me), you need to mix in lots and lots of organic matter. Manure, leaf mold, garden compost, etc. If you have wet clay soil, you need to add organic matter and perhaps some sharp grit to assist in drainage. Clay is good, rich soil, and just needs help with drainage.

Kale likes about one inch of water a week. If it receives too little moisture, the leaves don’t taste that great. Kale has a very mild flavor anyway.

Kale is very hardy, I can’t say that enough. *laughs* I’ve seen Kale totally lace-worked by cabbage white moths and even sometimes eaten all the way to the stems, and yet it still grows. I have also seen Kale buried by snow, and it never froze and kept growing until the snow was so heavy that the plant could no longer support itself. And the next spring, we found kale happily continuing to grow after the snow melted!

In my garden book mentioned above, it says that 20 plants will provide enough Kale for a family of four.

Start seeds 6-8 weeks before your last average frost date (which doesn’t occur until the first week of June for my location). Or you can direct-seed outdoors as soon as the ground thaws. Sow 1/4 to 1/2 inch deep, 4 inches apart. Or plant more seeds and just pluck out extra seedlings and use the pullings as baby greens in your next green salad. Yum!

The seeds should germinate in less than a week. Two weeks before last frost, start hardening off these babies in increasing amounts outdoors so they get used to nature instead of their comfy, cozy home environment.

When the plants are growing well outdoors, take care to prevent a cabbage white moth / cabbage looper invasion, or they will eat your crop seemingly overnight. Don’t use chemical sprays. All you need is either to hand pick the green loopers, crush the eggs, or rip off the infected leaves and discard far away from your crop. If you really really want to spray, spray on a diluted mixture of Neem oil. Bugs will say YUCK to neem oil and leave your plants alone.

To harvest, you can either yank leaves as soon as they are large enough, or wait until the whole plant gets big then harvest the entire thing.

You can eat the fresh leaves in a salad, or cook the leaves as you would spinach or chard. To store, you can cook leaves, strain excess water out and pack into freezer bags.

From the frozen cooked leaves, you can make lasagna fillings, cannelloni noodle fillings, spinach-type bread dips, or just reheat it and top with a bit of butter and salt and pepper. Kale doesn’t need much flavoring. But Kale makes a great substitute for spinach in recipes. And the best part, no one will be the wiser!

Now get out there and enjoy some Kale! It’s good for you and highly nutritious. You cannot go wrong with this vegetable. I find it much less fussy than growing spinach, because spinach bolts and goes to seed at the slightest inclination. But Kale doesn’t flower or produce seeds until it’s second year because it’s a biennial.



photo borrowed from

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