Growing Kale From Seeds (Step by Step Guide)

Kale is an easy crop to grow right throughout the winter as it benefits from exposure to light frosts. This makes the kale leaves sweeter. You’ll also find that there are many different varieties of kale that you can grow.

To grow kale from seeds:

Choose a sunny location in your garden that has a slightly acidic soil (pH 5.5 to 6.5).
Prepare your soil well by adding some aged compost and organic fertilizers.
Sow the seeds (2 per planting hole) around 1 foot (30cm) apart.
Seeds should be planted around ½ inch (1cm) deep.
Water the soil using a soft rose fitting so that you don’t dislodge the seeds.
Once the seedlings have emerged, thin them out so that you have one plant every foot (30cm).
Keep the young plants well watered.
Apply liquid fertilizer to your plants every two weeks while they’re actively growing.
You can harvest the lower leaves in around two months time.

How To Grow Kale From Seeds

You can grow a variety of different kale plants easily from seed straight into the garden. Alternatively, you can also start your seeds in pots and then transplant the seedlings into the garden if you wish. More about this later.

Here are detailed instructions on how to grow kale from seeds sown straight into the garden.

1. Choose Your Location And Prepare The Soil

Kale does prefer to grow in a sunny spot but can handle some shade. The location you choose for your kale depends entirely on where you live. If you experience a temperate climate with cold winters, try to choose a location that gets plenty of sun. However, if you live in a warmer climate, you might like to choose a spot that gets part-shade to protect your plants from the really hot sun.

Kale prefers a slightly acidic soil in the pH range of 5.5 to 6.5. Adding plenty of well-composted organic matter to the soil will help to increase the acidity and provide your growing plants with plenty of nutrients. You can also add some organic fertilizers such as fish emulsion or bone meal to give your seedlings a good start.

2. Sow Your Seeds

To sow kale seeds, it’s probably easier to create planting drills or rows rather than individual holes because the seeds are quite small. You can either scatter the seed throughout the row or place around 2 seeds in one spot and place another 2 seeds a foot further along the row.

Sowing seeds the second way will mean that you won’t have quite as much thinning out to do. However, if you choose to just scatter the seed, you’ll need to spend a little extra time thinning out the seedlings once they emerge.

Seeds should be sown around ½ inch (1 cm) deep. This will ensure that the emerging shoot will be able to break through the surface of the soil before it runs out of the energy that is stored in the seed.

Once the seeds are sown, water them well but gently. You can either use a hose with a rose attachment or a watering can with the same. You want to ensure that you don’t dislodge the seeds with the water.

3. Thin Out Your Seedlings

Your kale seeds should start to germinate in around 5 to 8 days. Once the seedlings are around 1 inch (2.5 cm) tall, you should thin them out. Do this carefully so that you don’t damage any of the seedlings that you want to retain. Ideally, you want to have your seedlings spaced around 1 foot (30cm) apart. This leaves enough space for the kale plants to grow their delicious leaves.

If you’re careful enough, you can transplant the seedlings that you’ve pulled out into another spot in your garden. Not all of them will survive, but some should. You could even transplant these into a pot that you can move around the garden.

4. Water And Fertilize Your Growing Plants

Kale plants do like plenty of water. The moisture will help to produce sweeter leaves. The easiest way to keep your plants watered is to set up some sort of irrigation system that you can either have on a timer or turn on periodically, even daily on hot days.

For kale, you can either use drippers for each individual plant or small sprinklers that will water two or more plants at once.

Kale also benefits from regular fertilizing during its growing season. It’s best to apply a liquid fertilizer once every two weeks to give your plants all the nutrients that they need. You could use liquid seaweed or fish emulsion mixed with water for this.

5. Harvest Your Kale

You should be able to start harvesting your kale in around 2 months’ time or when the lower leaves are a good size. Always harvest only the lower leaves as this ensure that the plant can continue to produce more leaves from the crown.

Harvesting this way means that you’ll have a continuous supply of lovely fresh leaves that are full of vitamins and minerals.

How To Start Your Seedlings Indoors

If you prefer to start your seedlings indoors, the process is fairly simple.

Select a pot or seed tray and fill with good quality potting mix or seed raising mix that you’ve added some additional organic matter to.
Sow the seeds, spacing them far enough apart to give the emerging seedlings some room to grow. You don’t have to space them as far apart as when planting into the ground because the seedlings will be planted out once they’re large enough
Water the pot or seedling tray and place it in a well-lit spot preferably near a nice bright window.
Keep the soil moist and you should see some seedlings start to pop up within a week or two.
Seedlings can be planted out into the garden once they’ve reached a height of around 5 inches (12cm) and once the outside temperature has started to warm up and there are no more frosts expected.

Frequently Asked Questions

Should you soak kale seeds before planting?

Soaking your kale seeds for around 24 hours in the water will generally help to speed up germination. However, this is generally not necessary because kale seeds don’t take all that long to germinate.

How big should kale seedlings be before transplanting?

Consider the general rule of thumb for most seedlings that each seedling should have around 3 to 4 true leaves. This is in addition to the first two leaves that emerge that are called cotyledons.

How often should you water your kale plants?

Kale is quite a thirsty plant and also a fast grower. Ideally, your plant should receive 1 to 1.5 inches of water every week.

If you want to know more about this topic, please check out my other article on kale’s sun, water and soil requirements .