Kale Is an Essential Plant to Grow in the Kitchen Garden

This member of the Brassica family, known for other nutritional superheroes like broccoli, cauliflower, cabbage, radishes, and arugula, has become increasingly popular over the last few decades. And I say for good reason!

Unlike cabbage, the leaves of kale do not form a head. Instead, they fan outward, making kale a popular plant to be grown for its ornamental value, in addition to its health benefits.

If you don't already have kale in your garden, you've got to give growing it a try. Thanks to its tendency to spread out higher on the stalk, you'll still have plenty of room to grow other plants around it, which helps to maximize your kitchen garden space and production.

Here's everything you need to know to have a successful kale harvest for seasons, and even years, to come.

My favorite types of kale to grow in a kitchen garden

There are many different varieties of kale you can grow in your kitchen garden. To help you narrow it down, here are my favorites:

red Russian kale

The frilly leaves of this variety are soft and a little bit sweeter than other varieties. They're great in salads, though I do prefer their taste when they're still small. Despite its name, Red Russian kale actually has beautiful purple stems that fade into the green leaves. This plant is more prone to pests than other types of kale.

dinosaur kale

Also called toscano kale and lacinato kale, this plant grows long, dark bluish-green leaves. Dinosaur kale plants are huge varieties that are resistant to frost and cold thanks to their savoyed (or crinkled) leaves. My favorite use for these leaves, besides to toss into smoothies, is to sauté them.

blue curled scotch kale

This is probably my favorite type overall for salads. The bright green leaves of this kale variety are so pretty they're often used as a garnish. They're sweet and crunchy, perfect for kale chips or kale soup. This plant is more resistant to pests than red Russian kale.

If you don't much care for the taste of kale you've had before, give another variety a try. There are actually about a gazillion types of kale out there, including pretty purple ones, and one of the main benefits of growing your own is to try kinds you won't typically find at the grocery store. You can become a connoisseur of greens and explore so many new tastes and textures. I'm typically growing several different types of kale in my kitchen garden at any given time because my family members each have their own kale preferences. (You could also try harvesting leaves when they're smaller and more tender to see if kale is more to your liking then.)

Learn more about these different kale varieties.

When does kale grow best?

Kale plants love cool weather, so they're best planted in the early spring as soon as the soil is workable or late summer. Established plants can actually push through the heat of the summer, even though it's not optimal growing time for them, as long as they receive plenty of water (you might find yourself needing to water daily during the hottest months). You will want to keep an eye on your kale in the warmer months (mostly for pests) and maybe plant some larger plants around them to lend some shade. You could also cover your garden with shade cloth to keep the soil a little cooler.

Once it starts getting colder, a little touch of frost will actually give your leaves a sweeter flavor. In other words, don't rip up your kale plants just because your cold season is on its way. For those of you with more mild winters, your kale will most likely continue producing leaves throughout the season.

Is kale an annual plant?

Kale is a biennial plant, meaning it can last up to two years before going to seed. The cool thing about biennials is that they're really motivated to stay healthy and last those two years (or at least 18 months) so that they can finally create more of themselves for the future. That's one of the reasons why kale can hang in there throughout harsh winters and hot summers. You'll find that biennials are often some of the hardiest little plants you can put in your garden.

Where should you grow kale?

Kale plants are pretty big, much bigger than, say, their little cousin arugula. I typically give each plant about a full square foot to itself. I grow all my kale in raised garden beds to give the roots plenty of room to dig down deep. Kale plants love well-drained soil, and I fill my raised beds with a sandy loam mix that's rich in organic matter.

If you don't have raised beds, you can grow kale in large pots or containers. Just look for something at least 12" deep and 12" wide, and having at least one good drainage hole in the bottom is a must. You'll need to monitor container-grown kale more closely since the soil will dry out much faster. (If you're starting seeds for kale that will grow in a pot or container, it's a great idea to look for dwarf varieties.)

When should you sow kale seeds?

Since kale is a large leafy green, I like to start seeds indoors. That way, I have a head start on my growing season. You can start kale seeds a good 90 days before your last frost date and move them outside when they're ready. Since they can handle some frost and snow, you don't have to wait until all chance of frost has passed. When I lived in Chicago, I started kale seeds indoors as early as February and moved them outdoors by March.

You can do the same thing in late summer if it's still hot outside. Start your kale babies inside and then move them out in the fall once the temps have finally dropped to the 70s. My friends in Houston typically start their kale seeds in September in preparation for when their average daily high finally dips below 75 degrees in November.

If you don't want to start your kale seeds indoors under grow lights, you can wait and sow them directly in the garden as soon as the soil is workable.

How do you grow kale from seed?

Sow each seed only about ¼ inch deep. Though kale seeds are small, the plant itself is large, so remember to give each seed at least half a square foot of room in the beginning if you're direct sowing.

I lick my finger and use it to pick up one or two kale seeds at a time. You'll be glad later when you don't have to thin your kale plants that you took the time to place only one seed per cell or planting hole.

Keep your seeds well-watered after sowing. The soil needs to stay moist to ensure germination. Kale seeds typically sprout in about 6 to 9 days.

Before moving kale started by seed indoors to the garden space, make sure your temps are between 35 to 65 degrees Fahrenheit. You'll have much more success if you wait till a nice, cool day to plant kale seedlings or starts in the garden. Water kale seedlings daily after moving them to the garden space until they have about 10 to 15 leaves.

You can save yourself some pest-related grief later by planting chives or garlic near your kale seedlings since the pests that typically like to munch on your leafy greens hate the smell of plants in the onion family.

How do you care for growing kale plants?

After your plants have 10 to 15 leaves, their roots are pretty established in the soil, so you can switch to watering every other day or every third day, depending on your climate.

Kale is not a particularly heavy feeder. As your kale plants grow, support them by adding some extra compost around the base of each plant. This process, called hilling, ensures your growing plants have all the nutrients, especially nitrogen, they need to produce lots of leaves for you to consume.

You could instead add an organic fertilizer high in nitrogen like cottonseed meal about once every 4 to 6 weeks (increase frequency if you're growing kale in a pot or container since the roots won't have as much room to reach out for needed nutrients). I rarely add fertilizer to my kale plants, and they produce tons and tons of leaves for me.

Prune any leaves that have holes in them or that are turning yellow. We'll talk about dealing with pests on kale in a bit.

When can you begin to harvest kale leaves?

It takes 50 to 55 days from planting before you can begin harvesting kale leaves. You'll know your leaves are ready to be cut when they're about as long as your hand.

Once your plants are ready to be harvested from, you should be coming out to your garden and cutting them frequently. Leaving mature plants with big leaves in the garden is not only an invitation to pests, it also blocks other plants’ access to sunlight and airflow. Prune away any leaves that are shading interior plants regularly.

Harvest the leaves during hotter months when they're young, as older leaves tend to become bitter.

How do you harvest kale leaves?

Anytime you're harvesting from leafy greens like kale, you're going to start with the older outer leaves. These will be those leaves closest to the base of the plant, as kale grows from the center out. By harvesting these older leaves first, you'll tell the plant to focus its energy on growing lots of new leaves. Over time, your plants will begin to look like mini trees with long, bare central stems.

Use a clean pair of needle nose pruners to cut stems as close to the central stalk of the plant as possible. I like to wipe my pruners down with some rubbing alcohol before taking them out to the garden with me. If you're in hurry, you can also gently twist each leaf to break it off the plant (the crunchy sound it makes is the best!).

The golden rule of harvesting is to never take more than a third of the plant at any one time. The reason for this is that the leaf cells are the ones that are taking the sun's energy and turning it into more food for more plant growth. Cutting too much within one week would risk destroying the plant's food-producing system. I take about four leaves from each plant at a time. Because I have so many kale plants, I rotate which ones I cut from each day so that they're all being harvested from regularly and then have time to recover and produce more leaves.

In total, harvesting from several plants takes about 30 to 40 seconds.

Explore more on how to harvest kale.

How often should you harvest from kale plants? 

You want to come in and harvest your leaves about once or twice a week. Again, this may seem counterintuitive, but the more you harvest your leaves, the more energy your plant will spend on making new leaves. 

The smaller new leaves are the best for fresh salads, and the bigger, more mature leaves are good for cooked dishes. Either size can be used for smoothies or juices.  

What type of pests attack kale?

Kale is prone to attacks from pests like cabbageworms, flea beetles, and aphids, especially when the weather warms. You'll know your leaves are being munched on by creatures other than you when you notice holes in the leaves or find eggs on the undersides.

I always say that the best defense is a good offense when it comes to the garden. Start with good soil that will keep your plants healthy and strong, capable of fending off predators on their own. Growing plants in their optimal conditions (so either in the cool season or with some shade during the warmer months for kale) and giving them the correct amount of water also deters pests.

Another good offense is to add a physical barrier to your garden once you've planted your kale babies. Read up on why this inexpensive garden mesh is my favorite organic form of pest control for my leafy greens.

How do you treat pest-affected leaves on kale plants?

The simplest way to deal with any kind of garden pest is to first prune away the parts of the plant that are damaged, such as any leaves that have holes or show discoloration. If you find yourself removing more than a third of the leaves, it's best to just pull the plant from the garden. After pruning, look around the soil, clean up any dead leaves and debris, and remove any pests you see. Give your kale plants some extra support by adding a fresh layer of compost around the base.

If aphids are your issue, give the leaves of your kale plants a strong spray with a water hose.

Wait a few days after taking these simple measures. If you still see pests or new holes in your leaves, then it's time to treat with an organic spray as a last resort. Lightly spray the leaves with a solution of Dr Bronner's castile soap mixed with water. Most pests that love greens also hate the smell of anything in the onion family, so you can alternatively spray the leaves with garlic barrier (this is an oil that you'll need to dilute) to prevent pests from returning.

If your pest problem is getting really serious, you could use Neem oil, and if it gets horrible, you could use Monterey Bt. Even though that’s an organically approved way to deal with the pests, I try to stick with physical barriers and preventative measures if possible.

Read more about how to handle pest issues with your kale plants, plus why it's safe (and actually better for you) to eat pest-affected leaves.

What are the health benefits of kale?

Kale is the quintessential superfood, with over 900% of your daily needs for vitamin K, which may reduce your risk of cancer, and over 600% of your needs for vitamin A. This Brassica even has more vitamin C in a single serving than an orange. Loaded with antioxidants, kale has been shown to help lower your cholesterol, which can, in turn, reduce your risk of heart disease and other cardiovascular issues.

What are the best ways to use you kale?

Kale makes a great addition to salads, stir fries, smoothies, soups, quiches, and sautéd dishes. I harvest kale for my green morning smoothies every single day. I also try to sneak kale into my kids' smoothies. (If you throw in some dark berries like blueberries or blackberries, it masks the green color, so they'll never even know there's kale in there. But Shh! don't tell my kids I said that!) My children do knowingly eat these kale chips—they're actually a big hit.

When you end up with more kale than you know what to do with, you can freeze the leaves or dehydrate them and then ground them up in a powder to use in smoothies all winter long.

Here's my favorite kale salad recipe if you need some fresh salad ideas.

Why is my kale flowering?

If your kale has made it through its time in the garden, it will halt its leaf production and begin forming the prettiest little yellow flowers on tall stalks. These flowers mean the kale plant is bolting, or focusing on seed production. While you won't be getting any more delicious leaves, you can actually eat the florets (they're best before they open). Kale buds are 100 percent edible and something that you'll probably only get to try if you grow your own kale.

Learn more about what to do when kale bolts.

Time to Grow Your Own Organic Kale

If you follow these simple guidelines when growing your own kale, you too will soon be heading out to your garden daily to snip some leaves. Trust me, you'll be kale'ing it in your own garden in no time!

Thanks for being here and helping to make the garden ordinary again!