How to plant kale in the garden


How to Plant and Grow Kale

Cold-hardy and resilient, kale is an easy member of the cabbage family to grow. You can set out plants quite early in spring as long as you protect the young plants from severe cold winds with a cover. They will grow steadily for months until the weather gets too warm. You'll get a second chance to plant kale in the fall, when cool weather brings out a wonderfully sweet, nutty flavor that is unique to these cold-natured plants.

Fall is the best time for growing kale in areas where winter doesn't dip below the teens, or in a cold frame farther north, because the leaves are sweeter when they mature in cooler weather. In the kitchen, kale can be steamed, stir-fried, or substituted for spinach in omelets, casseroles, or even quesadillas. It's a wonderful addition to smoothies, too, and tender young leaves make delicious salads.

Quick Guide to Growing Kale

Soil, Planting, and Care

Set out plants in spring 3 to 5 weeks before the last frost; in late summer, you can begin planting kale 6 to 8 weeks before the first frost for fall and winter harvests, and continue planting throughout the fall in zones 8, 9, and 10. Be sure to choose kale starter plants from Bonnie Plants®, so you know they'll be strong and vigorous.

Kale grows best in full sun, but will tolerate partial shade as well. Plants that receive fewer than 6 hours of sun daily will not be as stocky or leafy as those that get ample sun, but they will still be plenty edible! Like collards, kale likes fertile soil to grow fast and produce tender leaves. Enrich the soil with compost and fertilizer before setting out the seedlings. Apply fertilizer and lime according to test recommendations. If you forgo the soil test, work nitrogen-rich amendments such as blood meal, cottonseed meal, or composted manure into the ground before planting.

The soil pH should be 6.5 to 6.8 to discourage clubroot disease, although the plants will grow fine in a pH of 6.2 to 6.8 if clubroot is not a problem in your garden. To be sure about your soil pH, test the soil with a do-it-yourself kit, or by using your regional Cooperative Extension office. If that seems too complicated, you can simply improve your existing soil by mixing in a few inches of Miracle-Gro® Performance Organics®All Purpose In-Ground Soil with the top layer. Enriched with aged compost, it will improve both the texture and nutrition of the native soil.

Kale is easy to plant, and grows beautifully in both raised beds and containers. To create the ideal growing environment for the plant roots, fill raised beds with 100 percent organic Miracle-Gro® Raised Bed Soil and containers with Miracle-Gro® Performance Organics® All Purpose Container Mix. Set plants at the depth at which they are growing in the container. Space them 18 to 24 inches apart. The leaves will grow bigger if given a lot of space, but smaller leaves tend to be the most tender. After planting, water plants well. Plants grow best when they have access to both great soil and a continuous source of nutrition, so apply a water-soluble fertilizer such as Miracle-Gro® Performance Organics® Edibles Plant Nutrition regularly for excellent results.

At this point you may need to be patient, because spring-planted kale may stay small until slightly warmer soil temperatures trigger vigorous growth. Kale planted in late summer or early fall may sulk through spells of hot weather. Then, when conditions improve, the plants will take off, quickly multiplying in size.

Kale likes a nice, even supply of water, about 1 to 1.5 inches per week. You can measure how much water rain has provided by using a rain gauge in the garden. Mulch with compost, finely ground leaves, weed-free hay, straw, pine needles, or finely ground bark to keep the soil cool and moist and to keep down weeds. Mulching will also help keep the leaves free of splashing soil for a clean harvest.

You also have the option of growing kale indoors. An easy way to do that is in a hydroponic growing system like the Miracle-Gro® Twelve® Indoor Growing System. There's no soil—plants grow directly in water that circulates around the roots, delivering moisture, nutrition, and air. With plenty of light courtesy of a grow light, the system provides top-notch growing conditions for kale. Best of all, you won't even have to go outside to harvest.

Troubleshooting

Kale often grows as a carefree crop, but there are several insects that like kale as much as people do. Velvety green cabbageworms often can be found chewing holes in kale leaves. The larvae of cabbage white butterflies, cabbageworms are more likely to feed on cabbage, broccoli, and cauliflower than to bother your kale.

Colourful black-and-orange harlequin bugs often show up on kale plants that are feeling the stresses of old age. Rather than fight the harlequins, most gardeners pull up and compost old plants if it is mid- to late summer. In late summer, the best way to protect young seedlings from these and other pests (like grasshoppers) is to cover them with a row cover or some other lightweight fabric, such as wedding net (tulle). The covers can be removed in mid-fall, when pest populations usually drop dramatically.

Watch for outbreaks of gray-green cabbage aphids, which often gather in clusters within the folds of frilly kale leaves. Treat small problems with insecticidal soap. Pick off and discard badly infested leaves.

Harvest and Storage

Like collards, kale leaves are sweetest in the fall, after they've been touched by a light frost. Pick the oldest leaves from the lowest section of the plants, discarding those that appear yellowed or ragged. Pick your way up the stalk, taking as many leaves as you like, as long as you leave at least 4 leaves intact at each plant's top (or growing crown). Kale will produce new leaves all winter in zones 7 to 10. In climates where hard freezes are frequent, kale often survives winter with additional cold protection from thick mulch, row covers, or plastic tunnels. Overwintered plants will eventually bolt (producing yellow flowers) in spring, signaling that it's time to remove them and make room for other crops. Wash the leaves thoroughly and store them in a plastic bag. You can eat the stems or discard them—it's up to you. If you cook the kale, the stems will become more tender. Kale leaves will keep for several days in the fridge in a loose plastic produce bag.

Kale will produce the most tender leaves if the plants get plenty of moisture from the beginning.Full-sized kale plants are beautiful with big, frilly leaves that can be eaten whole in sandwiches, cut into salads, used as a garnish, or cooked alone or in soups.When the weather warms, your kale plants will send up flower stalks and produce pretty yellow flowers. The plants become ornamental in the garden, and you can cut the flowers for arrangements.This winter scene shows kale alongside leeks in a display of two of the garden's most cold-hardy vegetables.

FAQs

Should I harvest leaves when they are young or wait until they grow larger?

It depends. Young leaves work great for salads, but if you're planning to cook the greens, let leaves reach full size. Pick the largest leaves from the bottom and outside of the plant. Avoid picking or damaging the center of the plant where new leaves arise.

How long can I expect to harvest kale?

For many months. You can pick spring-planted kale all summer, but leaves may get tough and bitter when heat arrives. Quality improves again in fall and plants continue growing even winter in mild climates. Frost makes them taste sweeter, and plants are cold-hardy at least to the low 20s. The following spring, though, they will bolt. The same is true for fall-planted kale. Winterbor is an especially cold-hardy one that works well in cold weather. Gardeners in cold climates can enjoy it through winter in a cold frame.

Is there anything I can do to help kale leaves stay sweet?

Warm weather can make kale bitter and tough. While cool temperatures are the key to sweet leaves, you can help keep roots cool by mulching around plants. Making sure plants remain well watered also improves leaf flavor.

I picked kale last week and the patch still looks sparse. Is there anything I can do to jump-start growth?

Fertilize during the growing season for a steady supply of leaves. You can side dress plants with compost or blood meal, spray foliage with diluted fish emulsion, or water with a liquid fertilizer like Bonnie Herb & Vegetable Plant Food.

How long can I store harvested kale?

Kale stays crisp in the refrigerator for up to two weeks. Store it in an unsealed plastic bag with a damp paper towel.

Frost is predicted. Should I pick all the kale and store it?

Frost actually sweetens kale. This is the most cold-hardy of all vegetables and will take quite a few of the early frosts before a hard freeze, or "black frost" as it sometimes called, kills it in colder regions. In zones 7 and warmer it often continues to produce leaves all winter long.

Green worms are eating my kale. Can I spray anything that will kill the worms without hurting my family or pets?

Cabbage worm likes to eat kale. If you've noticed a white moth fluttering among the plants, that's the source of your worms. Spray kale with Bacillus thuringiensis (Bt) to control the worms. Bt doesn't affect humans or other wildlife. Bt targets worms, which die after ingesting it. After you spray Bt, worms may take a few bites from the leaves, but they'll stop feeding and die in a few days. Spray any time you spot the moths among plants.

How to Germinate, Water, and Harvest

Kale (Brassica oleracea) is essentially a form of cabbage that doesn't have the tightly formed head associated with most cabbages, and it's grouped in the cooking greens category with collards, mustard, and Swiss chard. Kale plants can be quite ornamental, with textured and curly leaves that come in shades of green, purple, and other colors.

Kale has a relatively fast growth rate and can grow from seed to harvest in about three months. It is best planted in the late winter or early spring and can also be planted in the late summer for a fall to winter harvest. This biennial plant takes two years to complete its growth cycle—so it grows leaves in its first year, while seeds and flowers develop in its second growing season.

Common Name Kale, ornamental kale
Botanical Name Brassica oleracea
Family Brassicaceae
Plant Type Annual, biennial, vegetable
Mature Size 1–2 ft. tall, 1–2 ft. wide
Sun Exposure Full sun, partial sun
Soil Type Loamy, moist, well-drained
Soil pH Acidic
Bloom Time Spring
Hardiness Zones 7–9 (USDA)
Native Area Europe

How to Plant Kale

Kale is a fast-growing vegetable that does best in a planting location with full sun. Plant kale seeds about 1/2 inch deep, leaving at least 1 1/2 to 2 feet between each plant. High nitrogen content in the soil is important for kale to grow its leaves, so adding a few inches of organic matter like compost to a well-draining soil mixture will encourage a healthy harvest.

When to Plant

Kale can be planted three to five weeks prior to your area’s projected last frost date in the spring. In most regions, gardeners can harvest kale in the summer by planting it at this time. It can also be planted in late summer roughly six to eight weeks before your first fall frost.

Those in warm climates (zone 8 and above) can continue to plant in the early fall for a late fall to winter harvest. Kale takes roughly three months to reach maturity from seed, while cuttings will mature in about one month.

Tip

Cuttings are an inexpensive way to create new plants. Plant your kale in early spring if you plan to take cuttings in late summer. Kale cuttings should be taken in about three months once the plant has become established.

Selecting a Planting Site

Kale grows equally well in pots, garden soil, raised garden beds, and other containers. Kale can grow indoors as long as you have adequate lighting. Soil that’s rich in organic matter and has sharp drainage is ideal, and the planting site also should get ample sunlight. Be sure the kale isn't too close to taller plants that will shade it. Growing kale in a window box can also be successful in south- or west-facing windows, but in very hot climates, east-facing windows can help prevent scorching from the afternoon sun.

Spacing, Depth, and Support

Space kale plants roughly 1 1/2 to 2 feet apart, and plant them at the same depth they were growing in their nursery container. Seeds should be planted around 1/2 inch deep. No support structure is necessary.

Kale Care

The Spruce / Debbie Wolfe   The Spruce / Debbie Wolfe 

The Spruce/Debbie Wolfe 

Light

Kale needs full sun to partial shade in most climates, as the fullest growth will occur when the plant gets six or more hours of direct sunlight on most days. However, if you live in a hot, dry climate, provide your plant with some shade, especially from the strong afternoon sun. Heat can make the leaves wilt and lose their flavor.

Soil

Kale plants like to grow in a rich soil that's high in organic matter with a slightly acidic pH (6.5 to 6.8). The high nitrogen content provided by organic matter is crucial for healthy leaf growth. The soil also should drain well.

Water

Kale needs consistent amount of water to stay healthy, generally growing best in 1 to 1 1/2 inches of water per week. Water your kale plants regularly to keep the soil evenly moist but not soggy. Along with cool temperatures, moist soil helps to keep the kale leaves sweet and crisp, rather than tough and bitter. Mulching around your plants can help to keep the soil cool and to retain moisture.

Temperature and Humidity

The plant is usually considered a cool-weather vegetable and can handle some frost once they're mature. The optimal soil temperature for planting kale is 60 to 65 degrees. All varieties prefer cool temperatures and will be sweetened by a touch of frost. Hot weather turns kale bitter. Kale is a biennial plant, taking two growing seasons (or years) to complete its life cycle, but it's usually grown as an annual. It will collapse if exposed to heavy frosts or snow. But it can be grown throughout the winter in USDA zones 7 through 9 if the winters are mild and there is adequate water.

Fertilizer

When planting, mix fertilizer into the top 3 to 4 inches of soil. Then, feed your kale throughout the growing season, following the instructions on your fertilizer label. Use compost or a high-nitrogen vegetable fertilizer.

Types of Kale

There are many kale varieties, and they're all worth a try. The curly-leaf varieties tend to hang on longer in cold weather. But the flat-leaf types generally become established faster. Here are some varieties to consider:

'Lacinato' kale

Anna Yu/Getty Images

'Redbor' kale

valery_green/Getty Images

'Red Russian' kale

romiri/Getty Images

Kale vs. Chard

Kale and chard have similar appearances. Their leaves are often large, crisp, crinkled, and deep green. Their difference comes in their taste. Kale is generally stronger, with a bitter and earthy flavor. And chard is a much milder green. Plus, kale’s thick stems are typically best removed before eating while chard’s stems may be tenderized by cooking them.

Harvesting Kale

Expect to wait approximately two months for your kale plants to mature from seeds. Check the days to maturity on your seed packet or plant label for more precise timing. Spring-planted kale will be good for harvesting throughout the summer months, but it's especially tasty after a light frost.

You can harvest young kale leaves to use fresh in salads or allow your plants to mature for use as a cooked green. Remove the older outer leaves, and allow the center of the plant to continue producing. Kale will keep in the refrigerator, ideally in the crisper drawer, for about a week.

How to Grow Kale in Pots

Kale is easy to keep in pots. Not only does this make the plant mobile so that you can move it into adequate sunlight and protect it from severe weather as needed, but it also helps to protect it from garden critters, such as rabbits, that might munch on the leaves. Plus, container growth is ideal if you don’t have garden space or the right soil conditions. 

Select a pot with at least a 12-inch diameter. It also should have ample drainage holes. An unglazed clay container is a good option because it will allow excess soil moisture to escape through its walls, helping to prevent root rot. Use a quality potting mix; an organic mix made for growing vegetables is a good option. Transplant your kale into the pot at the same depth it was growing in its previous container, and water it after planting.

Propagating Kale

Kale is most commonly planted from seeds or nursery plants, but it can also be propagated via cuttings. Kale does regrow after cutting, but it requires a specific propagation process. To pick kale to keep it growing healthy, cuttings must be taken from the oldest leaves. Here’s how:

  1. Use gardening shears to cut a stem from the bottom of the plant on its side, choosing one with multiple leaves from the main stem (do not propagate from the plant's center). Remove the leaves on the lower half of the stem. Trim the bottom of the stem right below a leaf node at a 45-degree angle. 
  2. Dip the cut end in rooting hormone.
  3. Plant the bottom half of the stem in a moistened soilless potting mix in a small container with drainage holes. 
  4. Continue to keep the growing medium moist. Roots should develop in a few weeks. If you can gently tug on the stem and feel resistance, you’ll know roots have formed. After that, it’s ready for transplanting.

How to Grow Kale From Seed

Growing kale from seed can begin inside or outside depending on your region. Kale can be direct seeded in the garden or started indoors and transplanted into the garden. You can direct seed in cold climates as soon as the soil temperature is at least 45 degrees Fahrenheit.

  1. Start plants indoors in a seed-starting mix about six weeks before your last expected frost date. Kale seeds germinate quickly in warm soil and should sprout up within five to eight days.
  2. Cover the seeds with about 1/2 inch of soil, and keep the growing medium moist.
  3. Transplant your seedlings from indoors after the danger of frost has passed.

Common Pests and Plant Diseases

Kale is a member of the cabbage family, which is notorious for attracting insect pests and for rot diseases. Kale is susceptible to black rot and clubroot, as well as aphids, cabbage loopers, cabbageworm, cutworms, flea beetles, and slugs. The best defense is to monitor the plants often for signs of eggs or feeding, such as holes in the leaves. Treat problems as soon as they arise.

Article Sources

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Kale. Cornell University Growing Guides.

When and how to plant cabbage

Cabbage is most often bred in seedlings. However, for a good harvest, it is not enough to grow healthy and strong seedlings - they must be planted correctly and on time in open ground. Beginner summer residents often have questions related to this procedure.

The very first difficulty is choosing the right variety. Depending on the ripening period, cabbage (we are talking about the most common type - white cabbage) is early (60-90 days from germination), medium (100-120 days) and late (more than 150 days). If your goal is to eat a fresh vegetable and cook soups, main dishes or salads from it, then choose early varieties. They grow quickly and have a more delicate taste. But if you expect to use cabbage for pickling, pickling or storage, then you can’t do without varieties of late ripening.

What kind of soil cabbage likes

In order for the cabbage to please with a harvest, you need to take care of choosing a suitable place for the garden bed where you will plant the seedlings.

First, let's figure out what kind of soil cabbage needs for normal growth?

  1. Cabbage likes neutral soil. If the soil in your area is acidic, you need to do it with liming. To do this, in the fall, add slaked lime or chalk to the future bed. In the spring, gypsum or dolomite flour can be used for this purpose. The amount of substances needed to deoxidize the soil depends on the level of its acidity.
  2. Cabbage in acidic soils or in conditions of high temperature and humidity is often affected by the most terrible cabbage disease - clubroot. There are no effective ways to deal with clubroot, so the only way to protect your plantings from the disease is preventive measures. Use fungicides as a preventive measure. A week before planting cabbage seedlings in open ground, treat the ground with a Bordeaux mixture (dissolve 10 tablespoons in 10 liters of water) or Fitosporin (1 tablespoon of the drug per 10 liters of water), and then add ash. The fungicide will protect plantings from fungal diseases, and the ash will reduce the level of acidity and enrich the soil with trace elements necessary for cabbage.
  3. Cabbage needs a sunny area with a deep - more than 2 m - level of groundwater. Although this vegetable is moisture-loving, however, constant stagnation of water negatively affects its root system and can lead to rotting of the roots.

When choosing a place, also pay attention to the predecessors that grew here last season. It is best to plant cabbage after nightshade, legumes, cucumbers, carrots, onions or garlic. Cabbage can be returned to its original place no earlier than after 3-4 years. If the vegetable was affected by keel, then this period increases to 7 years - that is how much keel spores live in the soil.

When to plant cabbage outdoors

The time of planting cabbage seedlings depends not only on the region, but also on the type of cabbage: early-ripening varieties are planted earlier, varieties of late ripening - later.

To determine exactly when to plant cabbage outdoors in your area, check the weather and plant appearance.

Harden off seedlings two weeks before planting seedlings outdoors. In the first 3-4 days, take out the plants (or open the windows in the room where the seedlings are located) for several hours. Increase the amount of time spent outdoors every day. 2-3 days before transplanting, leave containers with seedlings outside for the whole day. Seedlings prepared in this way will more easily endure the stress associated with changing the place of cultivation.

How to plant cabbage

Plant cabbage seedlings outdoors on a cool overcast day. The ideal option is before the rain, then the seedlings will quickly take root in a new place. A few hours before transplanting, water the seedling containers well with water so that the roots are less injured.

The distance between the rows of cabbage depends on the ripening period of the crop:

Rules for planting cabbage seedlings in open ground:

  1. On the prepared bed, make the required number of holes, the size of which should slightly exceed the volume of the earthen coma.
  2. At the bottom of the hole, pour a matchbox of wood ash and crushed eggshells (protection from the bear), mix everything with soil and lower the seedlings into the hole. If the site has heavy, dense soil, also add sand or low-lying peat to each hole, which will loosen the soil. Fill the planting hole with earth and carefully tamp.
  3. Make a small trench around the plant. When watering, the water will go from there directly to the roots of the seedlings and will not spread over the garden.
  4. Thoroughly water the cabbage.
  5. If the weather is sunny, cover the planted seedlings with newspapers or agrofibre. After rooting the seedlings, the protection can be removed.

To prevent overgrown seedlings from being broken by strong winds, bury them in the ground to the first true leaves.

How to care for cabbage outdoors

What is the further care of the planted seedlings?

First, watering . Make sure that the soil around young plants does not dry out. When they grow up, you can water the cabbage every other day, adding about 2 liters of water under each bush.

Second, loosening and hilling . Frequent watering makes the soil denser, and a crust forms on its surface. Because of it, the access of air to the roots of cabbage is difficult and the plant develops worse. For this reason, regularly loosen the soil around the bushes, destroying the compacted soil layer. However, watering not only contributes to the formation of an earthen crust, but also exposes the lower part of the cabbage bush, so during each loosening, add earth to each plant.

Third, feeding . Feed the transplanted seedlings for the first time two weeks after planting in open ground. To obtain the necessary nitrogen during this period, apply organic fertilizers or urea. The second time (after another three weeks), feed the cabbage with a complex mineral fertilizer.

Fourth, pest control . Not only we love cabbage - in nature there are a lot of people who want to feast on its juicy leaves. The main and most common enemies are cruciferous flea, caterpillars, snails and slugs. After their invasion, cabbage leaves can turn into a real sieve. To prevent this from happening, destroy pests by any means available to you. We already wrote about folk remedies for pest control of cabbage:

Properly cared for, cabbages will surely delight you with a rich harvest of healthy and crispy cabbages.

outdoor planting and care, cultivation, diseases and pests

Author: Elena N. https://floristics.info/en/index.php?option=com_contact&view=contact&id=19 Category: Garden plants Reissued: Last edited:

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