How to Grow Kale Indoors: A Simple Starter Guide (2024)

how to grow kale indoors featured

Kale is a green leafy vegetable with a distinctive taste and crunchy texture. Learning how to grow kale indoors is easy and very doable.  

This blog post will give you everything you need to know about what supplies are needed for this indoor gardening project, how to grow kale inside using natural light and hydroponics and different ways to grow kale in your home.

Kale is one of the healthiest vegetables you can grow, so why not try it?

What is kale?

Kale is part of the cabbage family and is a cruciferous vegetable.  Kale has become one of the most popular greens for home gardeners because it can be grown throughout much of North America during both spring and fall, making it an extremely versatile vegetable that provides you with fresh salads year round.

Kale is a nutrient-dense vegetable that contains large amounts of vitamins K, A, and C. In fact it has more vitamin K than any other food!

It also provides many health benefits including lowering the risk for heart disease and certain types of cancer as well as improving bone strength.

Does kale grow well indoors?

Kale is native to the Mediterranean and Asia, but it’s possible to grow kale indoors in many environments.  

Growing kale indoors is not that difficult, but it does require some patience. 

Kale can grow in a variety of containers, but the most common are grow bags and grow trays. 

A grow bag will generally be cheaper than a grow tray, while a grow tray will give you more control over depth of soil. 

Kale does well indoors and does not require a lot of light to grow. The plant will need to be watered once or twice each week, depending on the time of year and how much sunlight it receives.

Different Types of Kale

There are many different types of kale, all with slightly different flavors. 

Most people are familiar with the type of kale that is in most grocery stores.  It’s called Common Curly Kale and has a distinct look of curly leaves.  Amazon sells these seeds and you can grab them here.

There are also other types of kale that you can plant and enjoy. Follow the links to buy your seeds:

Red Russian Kale:  This variety has a nutty and mild taste.  It has flatter leaves, that are tastier than other varieties when raw. 

Lacinato Kale:  Also known as Tuscan kale, this variety is excellent for short-cooked meals, or eating raw. 

Dwarf Blue Curled Scotch Kale:  When harvested as small leaves, this variety is excellent for making kale chips.  You can also use it in salads and other meals. 

How to Grow Kale Indoors from Cuttings

1 |  Take off all leaves from the kale plant.  

2 |  Fill a jar about ¾ of the way full with water. 

3 |  Place stems in water.  

4 |  Put the jar of stems in a sunny windowsill

After about a week, you should notice new leaves beginning to sprout on the stems. 

At two weeks, your stems should begin growing roots.  

At this point, you can plant the kale in soil, or grow it hydroponically.  Read on for how to do both.  

how to grow kale indoors sprouting

Growing Kale Indoors from Seed

Growing kale indoors from seeds is very simple.  Just make sure you have the right supplies.  

Here’s what you will need:  

Here are the steps you will need to follow:

1 |  Put your potting soil in your seed tray.  

2 |  Place 2-3 seeds in each tray cell.

3 |  Cover the seeds with about ½ an inch of soil.

4 |  Lightly water or mist the soil so it is damp.  

5|  Place seed tray in a sunny windowsill, or under grow lights.

How Long Until Kale Seeds Germinate?

Kale seeds germinate quickly.  In ideal conditions, kale seeds will usually germinate in about 2-4 days. 

However, don’t worry if it takes your seeds up to a week to germinate.  It really just depends on the conditions of germination.

Thinning Out Kale Seedlings

Once your seeds have sprouted, you will need to thin out the sprouts so that your plants will be healthy.  This can be done about 10-14 days after your seeds have germinated.  

How Much Space Does Kale Need to Grow Indoors?

Kale does best when the plants are placed about 12” apart from each other.  

When growing kale indoors, you can use a pot that’s 12” across, or you can plant them in a large container and space out the individual plants accordingly.

Growing Kale in Pots

1 |  Fill a 12 inch pot (with drain holes) with a potting mix.  Kale likes loamy, well-drained soil, with a lot of organic matter.  You can add compost as needed.

2 |  Make a hole in the middle of the pot for your kale plant and place it in. It’s best to place it with its base about an inch below the surface of your potting mix.

3 |  Pack down the dirt around the kale plant and add potting soil as needed. 

4 |  Make sure the soil is moist, but not soaking wet. Water your cutting once it’s been planted until water starts coming out of the drainage holes in the bottom of your container.

If this is your first time growing kale, keep close watch on how much water your plant is receiving. 

If you notice that the soil in your container becomes dry very quickly, try adding a little bit of mulch to conserve moisture and reduce how often it needs to be watered.

Kale likes wet, damp conditions, so keep the soil moist at all times.

how to grow kale indoors transplant

Does Kale Regrow after Cutting?

Kale does regrow after cutting it, if you are harvesting it properly.  If you are harvesting the leaves, make sure you cut the oldest leaves, which are at the bottom of the stem.  

This will ensure the plant continues to grow.  If you cut leaves at the top of the stem, you risk killing in the plant.  

Does Kale Need Light to Germinate?

Kale will germinate faster if it has lights during germination.  You can speed up the process by placing your seed tray under grow lights.  

The second best choice is to set the tray near a sunny window.

Using Grow Lights to Grow Kale Indoors

Kale can be grown inside using natural light or grow lights.  If you don’t live in a location where the weather is sunny enough for natural light growing, you can easily set up grow lights to keep your kale plants healthy and happy.

Make sure your kale grow light emits mostly red or blue wavelengths–not green! Green signals plants that it’s time for growth rather than flowering, and this will make your grow light ineffective. 

The balance of blue and red light mimics natural sunlight, which is why it is most effective for indoor growing.  

For safety and proper growing, your grow lights should be placed 18 inches above the plant.    

how to grow kale indoors grow lights

Growing Kale Indoors Hydroponically

Kale does very well when grown hydroponically.  It’s actually a top choice for plants to grow using hydroponics and will yield a good crop when done correctly. 

Choosing a hydroponics system:  

The first step in setting up a hydroponic garden is to choose the right system for you. There are many different types of systems on the market, so do some research to find the best one for your needs.  

A simple system, like this counter top hydroponic system from Amazon is a great way to get introduced to hydroponic growing.  

A more involved hydroponics system will typically consist of a reservoir to hold the water, tubes or hoses for distributing this water throughout the system, some sort of plant container (such as pots), and an inert medium such as gravel or expanded clay pellets that offer support for these containers.

Once you have chosen your system, you can get started with either seeds or a transplant.  

Growing hydroponically from seeds: 

If you are using seeds, you will need to germinate your seeds, using the same method as detailed earlier in this post under “Starting Kale from Seeds.”

Once the seeds have germinated, leave them in the soil for about five extra days so they can continue to mature.  

When the kale plant has 3-4 leaves, it can be placed in the hydroponic system.

Growing kale hydroponically from an existing plant:  

You can grow kale hydroponically using an existing plant.  

To do this, you need to take a cutting of the existing kale plant.  Choose a healthy stem with several leaves on it to ensure successful rooting. 

You will follow the same directions as earlier in this post, in the section titled “Growing Kale from a Cutting”.  

Once your kale has rooted, you can transfer it to the hydroponic system.  

how to grow kale indoors hydroponically

How to Harvest Kale

Kale can be harvested when the leaves are about the size of your hand.  Usually it’s ready to harvest kale about 20-30 days after planting it.

However, you don’t want to harvest after it has started to flower and go to seed.  

The older the plant, the more bitter its leaves become, so keep that in mind.  The leaves would still be edible, but not as tasty. ] 

how to grow kale indoors harvest

You can either pick bunches of leaves off by hand or with sharp scissors.  Never more than a third of the plant should be harvested at a time, or you risk injuring and killing the plant. 

Store kale in an open plastic bag with a paper towel to absorb excess moisture. Do not wash it until you are ready to eat it; once cut or washed, it will lose its crispness and flavor quickly.

Kale can be steamed, sauteed with onions and garlic, or eaten raw in salads.  YUM!

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