No-Fail Kale: Growing Kale and Saving Seed

"The King of Vegetables; 'Kale' to the Chief!"

Cathy, Danielle and Llyn with "bouquets" of Red Russian kale to share at the Food Pantry.

Early spring in the Pacific NW is a time of joyful anticipation of the coming growing season. We already have hundreds of seedlings started in our greenhouses and, in a few short weeks we'll be able to transplant many early-season crops outdoors. But one of the great culinary pleasures of this time of year is the kale that wintered over from last season. Kale is one of those plants that when touched by a kiss of frost, becomes more sweet and tender than when growing at the height of summer.

Eat your kale for healthy skin, hair, bones and teeth!

There are many articles on-line about the nutritional benefits of kale and recipes for its preparation.  You will not find as many articles on-line about growing kale, using it as a cover crop, or saving your own seed which is what this article is focused on.

But, before we get into growing kale and saving seeds, in researching this post I discovered two important facts: Kale has the densest concentration of nutrients, per calorie, of a wide range of foods tested. (PDF of 72 tested foods) (explanation of chart).

And secondly, it is extremely important that, the source of the kale you eat is organically grown.

"The health benefits of kale greatly depend on the source you buy it from. Whenever you shop for kale, make sure to get organic kale, as it’s one of the most heavily pesticide-sprayed crops. Two-thirds of produce sampled in recent evaluations were poisoned with pesticides and non-organic kale ranks among the world’s most heavily polluted crops."(source)

How to grow it: Kale won't grow well in the tropics or arid regions but it's perfectly suited to a moist, temperate climate such as the Willamette Valley of Oregon where we live. There are several varieties available. The main two we grow are Toscana (or dinosaur) kale. With its greyish-green leaves (without many frilly edges) and mild-flavored tenderness, it is perfectly suited to make roasted kale chips (recipe below).

Toscana (or dinosaur) kale

But for ease of growing and hardiness through the winter, our favorite kale is Winter Red/Russian kale. This kale actually has the nickname 'hungry gap', after the period in winter in traditional agriculture when little else can be harvested. We've had stands of it survive through all but the most sustained snow and cold, outside and unsheltered through the winter.

Toscana kale is darker green and its leaves are less frilly (far left). Red Winter kale, hardier and more vigorous (easier to grow through the winter) is on the right.

Sign, we put with kale at the Food Pantry as many people were unfamiliar with eating it.

Typically we grow two main crops of kale per year. The first we start in early/mid-February.  We either start them in pots/six packs and transplant them outside (late March/early April) or we start them directly in beds in the greenhouse. We pick from both these plantings all the way until mid-July when a) the leaves become bigger and less tender and b) there is so much else coming ripe that we prefer to eat! In the heat of summer they also usually become infested with aphids and become inedible for this reason. This is also the perfect time to sow the second crop of the season (more on this below).

We start seeds in plastic tofu-containers with holes drilled in the bottom. We fill the containers mostly full of soil and press the soil down evenly with the bottom of another container. After sowing seeds, cover with scant, even layer of soil. Keep moist but don't over-water. These seedlings above are lettuce plants (to show spacing of seeds).

Once seedlings are large enough to handle easily and they have well-developed roots, but before they are root-bound, gently dump out the batch of seedlings and tease them apart, placing one in each cell of a six-pack.

In a few weeks, seedlings will grow and their roots fill the six-pack cells. They are then ready to transplant into garden-beds (18" apart). (Red Russian kale seedlings shown)

We have also sowed the seed loosely over a whole greenhouse bed in February (ideally the seeds are about 2" apart) and cover them lightly with topsoil. The kale comes up thickly filling the whole bed and grows rapidly in the protected climate of the greenhouse. It is easy to harvest whole clumps at a time with a sharp knife or scissors and, as long as you don't cut below where the leaves generate from, the kale will keep growing back all spring until a) you want to use the bed for something else or b) the greenhouse gets too warm for the cool-loving kale and it succumbs to aphids, or mold or gets too tough to enjoy.

Here, Chris is harvesting kale that was sown directly in a greenhouse bed. Using a sharp knife, he cuts off whole handfuls of kale leaving the node where new leaves sprout untouched for future harvests. The leaves will continue to re-grow for many, many months.

The second main crop of kale (for fall and winter eating) is sown in late July. It can be done in pots and transplanted, or loosely scattered as a thick crop (either inside or outside a greenhouse). It's counter-intuitive that you start these 'winter crops' in the peak of the summer heat but the seeds need enough time to germinate, and the leaves need long enough days to gain some height and volume as they will not gain much in size once the day-length shortens after autumn-equinox (Sept. 21 or so). We usually find it challenging to have enough room in our greenhouses at the peak of summer to grow a large kale crop indoors but, since kale does well outside, except in all but the harshest winters, we've had good luck with growing it outside.

Kale as a cover-crop: Below are some pictures of an experiment we did one year with kale as a cover crop. We sowed it thickly along with fava beans (tried to space plants about 2" apart). This was done by scattering the two varieties of seed and very lightly tilling them in with tiller at shallowest depth-setting. The kale did very well and lasted all through the winter. The fava beans succumbed to a sustained hard-frost and didn't survive till spring. After eating kale all winter-long, we tilled the rest in as a source for 'green manure'. This worked fine but we are now moving away from using the roto-tiller in the spring as it really compacts our clay-dense soil but, if you're still tilling in cover-crops and have a lot of kale-seed, it's a great way to go!

Kale and fava beans as a cover crop (planted in Sept., pictured in late October). Kale survived the winter; favas did not (froze). We ate kale all winter and tilled the kale into the soil in the spring as a 'green manure' (for fertility).

The same field of kale in February. OSU students harvesting a tub-full to take home and enjoy!

Springtime bonus: Kale 'raab'
Though there are some annual varieties of kale, most are biennial and set seed in their second season, after wintering over. If you have some kale that has survived the winter, look for the start of flowers forming. The best time to catch them is before the flowers begin to open (below). These kale flowers, called 'raab' (pronounced 'rob') are very tender and have a slight 'sweet' taste. They are loaded with vitamins and minerals.

Kale 'raab' (pronounced 'rob') is the flowers of the plant before they fully open. Tender, sweet and densely nutritious; a springtime treat! (pictured: Red Russian kale-raab) Note: Pick some leaves and stem along with the flowers; they'll still be tender at this time of year.

Here's Llyn picking raab off a Toscana kale plant in March or April.

Bella loves kale, raw from the garden! We prefer to steam it for about 7-min. and eat it with apple-cider vinegar or a touch of butter.

Saving seed: One of the pleasures of growing your own food from seeds is to begin to save your own seeds. With most varieties, it's not difficult and the seeds you save yourself will naturally select/adapt to be more perfectly suited to your local climate and conditions. It also contributes to having a greater sense of local food-security in case there ever comes a time when seeds are not distributed over long distances, or there is a seed-crop failure in another part of the country.

If left to mature, the raab opens up into yellow flowers. Once the flowers open, the plants become more woody and less pleasant to eat.

The flowers are pollinated and become seed-pods. Each plant can produce thousands of seeds! Wait to harvest the seed-pods till they are mostly turning purplish/tan and the pods are drying out (see above).

When ripe, the pods will easily open by rubbing them between your fingers yielding multiple seeds in each.

It's important to find the right time to harvest seed. You want to be sure the seeds are ripe enough that they are fully black and pop easily out of the pods, but don't wait so long that the birds eat your seed, or the pods shatter and spread the seed onto the ground below. Regardless of your best intentions, there are always some seeds that shatter out of the pods so you can anticipate 'volunteer' seedlings to germinate in places you've let kale plants go-to-seed.  We have one place in a greenhouse that has germinated kale plants for a third season in a row since we last let plants go to seed in that spot. That's what we call a 'high-quality problem'!

Mature kale seeds. Each plant is capable of producing thousands of seeds. This is just a small fraction of those saved from one plant.

You need to have some way of catching the seeds as the pods dry and open. After clipping the ripe seed-stalks, slip them gently in a paper-sack and hang in a dry place where birds and other animals can't reach them until the pods are all dry. You can also put them upside-down in a plastic tub or bucket. We have hung them from the rafters of our garden-shed, or on a shelf above our wood-stove, or put them in the greenhouse in a tub, on a shelf, covered by screens (to keep animals from eating them).

Seeds are ready for winnowing (separating seeds and chaff) when the pods are crisp and dry and crush easily by rubbing them between your hands. If it isn't in a tub already, carefully place the stalks of seed-heads into a tub and rub the pods between your hands to shatter them and release the seeds. As each stalk is cleaned, remove it from the tub. In the end you will have a mixture of seeds and dried leaves/pods (chaff). Winnowing is described in the caption below.

Here, Chris is giving a demonstration to Rook and Cindy of winnowing bean seeds (separating the seeds from the chaff). On a lightly breezy day, or in front of an electric fan, slowly pour seeds from one container into the other so the breeze blows the chaff away and the seeds fall into the lower container.

Storing seeds: Often, after winnowing, we continue to dry the seeds on a shelf above our woodstove. It is very important that they be totally dry or they can develop mold during storage. Heat can also destroy seeds so don't dry them any more than is necessary. Store seeds in a cool, dark place (or in your freezer, in an airtight container if you have the room). If you are new to saving seeds, check the plastic bags, jars or bottles a week or two after you store them to check there's no mold growing. We've lost a few batches due to mold which is always a sad thing when you go to check your seeds at the beginning of the next growing season.

Here's a LINK listing all our other posts about saving your own seed.

Delicious and nutritious, spring "greens": Toscana and Red Russian kale flanked by "Red Sails" lettuce.

Kale is easy to prepare and eat. We mainly use it steamed with a little apple-cider vinegar or lemon juice sprinkled on top, or a little butter but it it also good in smoothies (recipes), fresh in a tossed salad (recipe) or baked into chips (recipe). There are many great recipes on line. Always rinse well before using.

In the spring, when plants are small, the ribs will be tender and can be chopped right in with the rest of the leaves. As the plants mature, the ribs become more woody so best to slice them out and compost them.

Kale is incredibly nutritious. A 3.5 oz. serving (100g) gives you 7% of an adult's protein needs for the day as well as 5%- 15% of several vitamins and minerals. It is also very high in fiber.

(LINK: Health Benefits of Kale)

This 'ANDI' chart (below) lists 72 foods, rating them by their concentration of nutrients per calorie. Kale is #1! They're not suggesting that you rule out the foods that are higher in calories and less dense in nutrients (healthy bodies need high-quality fats, carbohydrates and protein) but most of us are deficient in the micro-nutrients (vitamins, minerals etc) and fiber, that are essential for all our metabolic processes and optimal health. (LINK: Aggregate Nutritional Density Index - note, kale is #1) (LINK to one-page, printable ANDI chart).

'Rob' with kale 'raab'