How to Grow Kale Indoors: Harvest Leaves All Year Long!

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A mature kale plant and tips for how to grow kale indoors.

Learning how to grow kale indoors can really save you money, time and aggravation. Have you ever gone to grab that fresh kale you bought at the store the other day only to find a wilted, unappetizing mess? I sure have- it can really throw a clinker into your kitchen plans.

Why not avoid the disappointment altogether and raise kale at home? Indoors, no less! 

From my experience, kale is a pretty low-maintenance crop. Once you get the basics down, you’ll be able to enjoy delicious and nutritious greens all year long. 

In this article, I’ll show you everything I know about growing kale indoors, the varieties you may want to grow and where to find the best kale seeds.

Let’s jump in!

PS: Kale isn’t the only crop you can grow right inside your own home! Mint is another great option. So stop by our post on how to grow mint indoors to learn more! 

Best Kale Varieties to Grow Indoors

There are three main types of kale out there:

  • Curly leaf, including dwarf Siberian and blue curled
  • Red, including red Russian and redbor
  • Lacinato

Any of these types should grow well in an indoor setting. 

Here are some top varieties to consider:

  • Dazzling Blue. I’ve always found Dazzling Blue kale to be a reliable producer- it’s my personal favorite! In my garden, Dazzling Blue gets about 2 feet tall, but indoors and in a tighter growing container, it should only get about 12 tall.
  • Dwarf Siberian Kale. This is a curly-leaf variety that produces a tight bunch of leaves. In the garden, dwarf Siberian kale can get up to 36 inches tall; in a container, it should max out at about 16 inches.
  • Redbor kale. This one can get big (3-4 feet tall!), but it’s still a good choice for indoor growing as a microgreen or baby kale.
  • Dino Kale. Also referred to as lacinato or Tuscan kale, dino kale has very hearty leaves which allow it to keep its firm texture even after being cooked. It should reach a maximum size of 12-16 inches indoors.

What Supplies Do You Need to Grow Kale Indoors?

When it comes to growing kale indoors, it’s not quite rocket science, thankfully. This is actually a great first crop to grow if you’re a new gardener, and it’s also an easy addition to anything else you have going on if you’ve got some growing experience under your belt.

Here’s your list of essential equipment:

  • A pot or container
  • Soil
  • Kale seeds or seedlings

Let’s break it down in more detail:

A Pot or Container

You can successfully grow baby kale or dwarf varieties in a pot as small as 6 inches in diameter. But if you have the space available, a pot that’s a little more spacious will yield the best results. Look for one that’s at least 8 inches in diameter, although one that’s 10 or 12 inches is preferable.

Your kale will happily grow in plastic, terra cotta, ceramic or any pot material you want to use. Just be aware that porous materials like terra cotta and unglazed ceramic allow moisture and air to pass through the pot walls, so you’ll have to water your kale plants more frequently.

No matter what pot size or material you choose to use, make sure it has at least one drainage hole in the bottom.

If you’re growing your kale from seed, you’ll need a tray to start your seeds in.

Since the seeds and new sprouts are so small, it’s easy to overwhelm them with too much water. I like to use a seed-starting tray with small sections for individual seedlings makes it easier to care for your plants properly, and it also makes the transplanting process a bit simpler later on.

I like these seed-starting tray kit, which includes a humidity dome (humidity helps encourage faster seed germination and healthier sprouts):

A seed-starting tray with humidity dome.

In the past, I’ve also had good results starting seeds in paperboard egg cartons. The paper material allows for airflow and water drainage, so it’s easy to work with.

In this case, use plastic wrap or a large, empty plastic container to create a humidity dome of your own. I’ve like to use empty plastic food containers as humidity domes, just like this video from Daisy Creek Farms shows:

Potting Soil

Always make sure to purchase soil labeled “potting soil” or “potting mix.” These are light, fluffy soils that are specially formulated for growing plants in pots, and they’re not the same thing as “topsoil” or “garden soil.” Top or garden soils are heavy materials that will easily compact in pots, which makes it hard for your kale plants to spread their roots and absorb nutrients.

Since you’re growing an edible indoor crop, an organic potting mix is a wise choice.

High-Quality Kale Seeds or Seedlings

 For your best shot at raising a thriving indoor kale garden, you need to start out with healthy seeds or seedlings. 

Purchase seedlings from a local nursery or home improvement store, or see if you can get some from a neighbor/friend in the spring or early summer.

If it’s not the right time of year to buy kale seedlings, don’t worry- I’ve always started my kale from seed and it’s super easy.

Most varieties of kale seeds are easy to come by at big box stores, garden supply stores and even grocery stores. And of course, you can always order your seeds online. I like these seed companies:

Planting Kale Seedlings or Seeds

Once you’ve got your supplies, it’s time to get to planting!

Planting kale seedlings. Seedlings that you can buy from garden centers are typically around 6 weeks old and somewhere in the neighborhood of 4-6 inches tall.So they should be mature enough to go right into their permanent pot.

Fill your pot with soil and dig a hole 4-6 inches deep. Take your kale plant from its nursery pot and set it in the hole, filling in the space around the root ball with soil. Give your plant a good watering and set it in a sunny window or under a grow light.

Planting kale from seed. You’ll need a couple of extra supplies for starting kale from seed. Here I’ve got some potting soil, a seed starting tray and of course, seeds:

Soil, seeds and grow tray for growing kale indoors.

Fill whatever seed-starting tray you’re using with dampened potting soil, drop two kale seeds into each well:

Two kale seeds in each cell of an indoor grow tray.

Lightly cover the seeds with a thin layer of soil. Kale needs to be sown about ½ inch deep, so just use a light sprinkling of soil.

Add the humidity dome, and place your seeds in a warm, sunny area. Don’t worry about the grow light yet- that will come a little later on.

Keep the soil moist but not wet. A spray bottle or a small squirt bottle works well here:

A gardener uses a squirt bottle to water a tray of indoor kale seeds.

You should start to see kale seedlings sprout up in about 5-7 days:

Kale sprouts in a grow tray.

Once your seeds have sprouted, take off the humidity dome and set up the grow light to run for about 8 hours each day:

Kale sprouts in a grow tray under a grow light.

Once your seedlings are about 1 inch tall, thin them to only one plant per section. When your seedlings are 2 inches tall and have two sets of true leaves, they’re ready to transplant into a larger pot:

Curly leaf and lacinato kale seedlings in a grow tray are ready to be transplanted into a larger container.

NOTE: I had a grow light issue for a while, so that’s why I lost some sprouts- but still plenty of healthy ones left! Things like this happen, so that’s why it’s always a good idea to plant more seeds than you think you’ll need.

I personally like to take the extra step of moving small seedlings into a container that’s only larger than the seed tray for a couple of weeks before moving them to their full-size pot. It’s far too easy to overwater delicate seedlings in a large pot, so I like to avoid the danger by keeping them in a smaller container:

A small lacinato kale seedling in a small container.

However, if you don’t have any mid-size containers, you can plant your seedlings directly in their full-size pot- just make sure to water carefully.  

Once the seedlings are about 4 inches tall, I transplant them into their permanent homes:

A curly leaf kale seedling ready to planted in a large pot.

And here are both my lacinato and Dazzling Blue kale seedlings, all potted up for the long haul:

Curly leaf and lacinato kale seedlings planted in large indoor pots.

Caring for Your Indoor Kale Plants

Once you have your kale planted in its container, it’s time to start nurturing it into something delicious. Kale is an easy-going plant that needs three main things: 

  1. Sun
  2. Water
  3. Fertilizer

Let’s look at each one: 

Sunlight

Kale needs lots of sunshine to keep its chlorophyll running, so aim for about 6 to 8 hours of light per day. You can supply the light your kale needs either through natural sunlight or a grow light.

If you have a window that gets full sun, put your potted kale there. However, keep in mind that kale does best in cooler environments and can get overheated, resulting in the plant wilting and even dying. So if the sun is beating down or your window receives direct sun for more than the recommended time, move your kale plant into a shadier spot. 

I’m going the grow-light route since I have my plants in a basement room that definitely doesn’t get much natural light.

I have my potted kale on a tabletop, and I’m using a free-standing grow light with multiple arms that let me direct light to several plants. Another option is an indoor smart garden, like Click and Grow or AeroGarden. Smart gardens are hydroponic systems with built-in grow lights on an automatic timer, making the growing process super easy.

Water

Kale needs regular water to thrive and produce maximum nutrients. However, no plant does well with too much moisture, so use the soil itself as your guide for how often to water. 

You’ll know it’s time to give your kale some water when the soil is dry about 1 inch deep.

Check the soil moisture by carefully sticking your finger into the pot. One inch is typically about the length from your fingertip to your first knuckle. When the soil starts to feel slightly dry, it’s time for a drink. 

Fertilizing

Don’t worry about fertilizing your kale seeds or seedlings right away- instead, wait until they’re about 2 inches tall. Anne Fletcher, indoor gardener and founder of Orta Kitchen Garden, agrees. “If you start with high-quality potting soil, there is no need for fertilizer for the first few weeks.”

But after that point, your kale will need a regular nutritional boost to produce the most nutrient-dense leaves for you to eat. A balanced vegetable fertilizer will work just fine and is easy to apply. My personal favorite fertilizer for edible crops is Dr. Earth Home Grown.

Follow the frequency directions on your fertilizer package for specific instructions. Typically, you should plan to fertilize your kale plant about once every 1-2 weeks.

NOTE: Like any chemical, be sure to store your fertilizer away from children or pets. 

How Long Until You Can Harvest Your Kale?

With the proper care, your kale will be ready to eat in as little as a couple of weeks if you’re growing microgreens, about 4 weeks for baby greens and about 8-10 weeks for full-sized kale.

Once your kale has grown to maturity comes the fun part: Harvesting and eating your freshly grown kale. 

Kale is a cut-and-come-again plant- it will continue to produce new leaves as you harvest mature ones. As long as you keep taking good care of your kale, you should be able to enjoy fresh greens for months.

To harvest your kale correctly, start at the bottom of the stalk and move upwards. Be sure to leave a minimum of four leaves so the plant can continue to grow. 

Now all that’s left to do is rinse your kale off and get to eating!

Why Should You Grow Kale Indoors?

All leafy greens are healthy foods, but kale is one of the most nutrient-dense plants you’ll find on the planet. Here are just some of the health benefits you can expect when you make kale a regular part of your diet:

High in Antioxidants. Antioxidants work to identify and neutralize free radicals, helping your cells stay healthy, strong and doing their thing! (This is an incredibly condensed explanation, so if you’d like to learn about antioxidants in more detail, Healthline has a great article!)

Great Source of Vitamin C. Vitamin C is famous for immune support, but it’s also essential for healthy muscles, bones, blood vessels and more. Plus, Vitamin C is a potent antioxidant!

Protects Your Vision. Kale contains numerous vitamins and minerals that can help your vision stay clear and sharp:

  • Lutein
  • Beta-carotene
  • Zinc
  • Zeaxanthin
  • Vitamin E

Outstanding Source of Vitamin K. Vitamin K can help your bones stay dense, potentially lowering your risk of fractures. Eating 1 cup of cooked kale daily lets you exceed your daily requirement by 500%!

What’s more, kale also contains calcium and phosphorous, which are also critical to healthy bones.

Infographic outlining how to grow kale indoors.

Frequently Asked Questions about Growing Kale Indoors

If you’re growing kale microgreens, they should be ready for harvest about 14 days after sowing the seeds. Baby kale leaves are usually harvestable in about about a month, and leaves reach full maturity in roughly 2-3 months.

As long as you harvest the lower leaves, your kale will continue to produce new leaves from the central stalk. But if you cut any leaves from the growth tip, the plant will no be able to produce new leaves.

Yes, kale is a perfect indoor crop in any season. Depending on your local climate, even full sun exposure might not me strong enough to support a kale plant in the dead of winter, so you’ll need to use a grow light to supplement.

Final Thoughts

Kale is a favorite plant of mine, and I love that growing it indoors lets me enjoy it any time of year! I hope these tips from my experience will help you grow your own thriving, healthy indoor kale crop!

Have you ever tried growing kale indoors? Do you have any tips, tricks or kale recipes to share? I’d love to hear them in the comments!

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