Are you looking for a nutritious vegetable to grow? Look no further than kale. Whether you want a spring or fall harvest, kale is a hardy addition to your cool-season garden.
In this post, I’ll go over how to plant kale, along with kale care and harvest tips. Let’s dive in!
A Quick Overview of Kale
Why Plant It
Like many other leafy greens, kale is a nutritious source of vitamins and antioxidants. It’s low in calories. And it’s packed full of calcium, potassium, vitamin C, and vitamin B6.
Add kale to your favorite smoothie recipe, or try it as a side salad. Or, create kale chips in the oven at home.
So, the big question is: is kale easy to grow? The answer is yes! Kale germinates easily, and it will withstand cold temperatures and shady growing areas.
It’s even easy to grow kale indoors, so you can have fresh vegetables in the off-season, as well.
Popular Varieties
If this is your first time starting kale seeds, you may wonder which variety is the best to grow.
Some key beneficial traits to look for include bolt resistance (going to seed), cold tolerance, and heat tolerance.
Here are a few of the varieties I recommend trying:
- ‘Red Russian‘ – One of the most popular kale varieties, ‘Red Russian’ has a tender texture with a sweet taste. The purple stems have large, light green leaves that resemble oak leaves. It has an extended growing season due to its cold tolerance and bolt resistance.
- ‘Blue Ridge‘ – This variety has curly green leaves with a crispy texture – perfect for a side salad. It’s known to mature early during mid-season. And, it’ll yield fresh leaves for a long period afterward.
- ‘Scarlet‘ – This curly variety has a beautiful deep purple color, which expresses itself more in cool weather. This is one of the most nutritious varieties to grow. And, it has great bolt resistance and cold tolerance.
- ‘Lacinato‘ – If you want a unique variety, ‘Lacinato’ features long, slender leaves instead of the usual curly, round leaves. Despite its uniqueness, this variety is very productive. It’s cold-tolerant, and you may even find it producing all year round.
When to Plant Kale
Before we go over how to plant kale, let’s discuss the best time to start it.
Many varieties of kale grow year-round, but it’s primarily known as a cool-season vegetable. This is when you’ll see thriving growth. In fact, some varieties’ flavor, such as ‘Lacinato,’ is enhanced by the cold.
For a spring crop, you can sow seeds up to six weeks before the last anticipated frost. For a fall crop, begin sowing seeds six to eight weeks before the first frost.
How to Start Kale Indoors
Kale can be direct sown, as we’ll discuss below. But the best way to start kale is indoors. This will give you transplants ready to produce an early harvest.
What You’ll Need
You’ll need the proper equipment for starting kale seeds.
Here are the products I recommend for your seed starting setup:
Seedling Starting Equipment | ||
 | Hoss Germination Mat | |
 | Indoor Seed Starting Light Kit | |
 | SunGrow Black Gold Seed Starting Mix | |
  | Potting Mix | |
 | 48 Cell Seed Starting Kit | |
  | Small Containers | |
  | Gardening Gloves | |
  | Garden Shovel | |
 | Spray Bottle | |
 | Watering Can | |
 | Garden Labels | |
Hoss Tools also has several seed starting kits that come with a combination of these items.
And don’t forget to snag all the seed varieties you wish to try. Hoss carries all the kale varieties I mentioned above. Another of our favorite seed retailers, True Leaf Market, also has several unique kale varieties to try.
Starting Kale Seeds
To start kale seeds, fill several seed starting trays with a soil-less seed starting mix.
Once the mix is moistened, and air pockets are removed, the mix should be flush with the top of the tray.
Using a pencil, plant label, or even your finger, create two indentions in each tray cell.
Each kale seed should be placed a 1/4 inch deep. Lightly cover the seeds with soil, and place each tray under a full-spectrum grow light.
For faster germination, set the trays on a heat germination mat. You can also use a humidity dome to increase moisture.
Kale seeds will typically germinate within three to 10 days.
Thin seedlings to one per cell after they develop two sets of leaves.
Tips for Transplanting
After starting kale seeds, seedlings will be ready for transplant in a matter of a few weeks. Seedlings should be approximately two to three inches in height before moving to the garden.
Seedlings can be transplanted at any time before the first frost.
When planting kale seedlings in the garden, space them out every 12 to 18 inches. This will allow enough room to avoid crowding mature kale plants.
How to Start Kale Seeds Outdoors
If you prefer to skip starting kale seeds indoors, no problem! Let’s go over how to plant kale by direct sowing outdoors.
Choosing the Best Location
Most kale varieties prefer to grow in full sun. But you’ll find that many kale varieties grow fine in partial shade. Make sure to read over the specific requirements of your chosen kale variety.
Soil should be neutral to slightly acidic, maintaining a pH of 6.5 to 7.0. The soil should also drain well, so avoid heavy clay soil or low-lying areas.
Kale is a great vegetable to grow in a raised bed, which makes it easy to manipulate soil conditions. Add composted organic matter before sowing seeds to improve soil health and boost kale growth.
Sowing the Seeds
Sow kale seeds every three to four inches. Seeds should be placed a 1/2 inch deep in the soil.
Once seedlings sprout and reach a few inches tall, they can be thinned to every 12 to 18 inches.
Caring for Kale
Water
Kale loves to grow in consistently damp soil. Make sure to visit your garden area more often in warmer months. During this time, kale grows fast, and the soil will dry out more quickly.
Using a watering can or drip irrigation, apply around one inch of water to kale every week.
If the soil is still moist, skip watering to avoid waterlogged soil.
Fertilizer
If you have rich soil mixed with organic matter, you can usually skip the heavy fertilizers.
But if your garden needs a little help, kale can benefit from a dose of nitrogen, phosphorus, and potassium. All three of these can be found in an all-purpose fertilizer.
Try out Hoss’ All-In-One Vegetable Fertilizer or one of these other fertilizers for seedlings.
When and How to Harvest
Most kale varieties will reach maturity in 65 days. But you can begin harvesting kale earlier if you want baby leaves for a salad.
Young kale leaves will have a more tender texture, while mature leaves tend to be crispier.
To harvest kale, remove the outer leaves of the plant using a sharp knife or pruning shears. Young leaves grow from the center and may not be ready to pick yet.
Kale will store in your refrigerator for up to two weeks. To preserve it for longer, you can also can kale or freeze it.
Wrapping Up How to Plant Kale
Learn how to plant kale, and you’ll instantly brighten your cool-season garden. This easy-to-grow vegetable is nutritious and weather tolerant.
Try it in combination with lettuce, spinach, and Swiss chard for a variety of leafy greens!
Along with starting kale seeds, there are so many fun vegetables to try. Visit the Seed Starting Page on our website for tips on how to grow all kinds of flowers and vegetables. We’ll even let you know which seed starting products are the best to use!