How to Grow Kale in the UK

Perfectly suited to the UK climate, kale is a versatile member of the cabbage family that’s delicious in a variety of dishes – including as a tasty side, in soups and stir-fries, pesto, pizza, and much more. And not only does it taste great, it’s a serious superfood, packed full of nutrients, vitamins and antioxidants.

So, how do you grow kale? This guide will give you all the information you need to cultivate this brilliant brassica in your garden or allotment.

There are several varieties of kale that perform well in the UK’s climate. Popular choices include the classic Curly Kale known for its frilly leaves and robust flavour. Cavolo Nero, also known as Nero di Toscana, with its dark, textured leaves, look stunning with a light dusting of frost, and Red Russian brings a splash of colour with its reddish-purple stems. Selecting the right variety can enhance both the aesthetic and culinary appeal of your garden harvest.

It’s estimated that around two million tonnes of kale are grown every year around the world, mostly in China, but also in India, South Korea, Russia, Ukraine and the USA, but it’s much more fun to grow kale at home! So how do you plant kale? Let’s dig into the answer.

How to grow and plant kale is relatively easy. You can plant kale directly into its final growing position, though some gardeners prefer to start the process indoors and transport the plants into the garden when they’re ready.

Starting the Planting

Begin sowing kale seeds indoors about four to six weeks before the last expected frost in your area. In the UK, this typically means starting in March or early April for a spring planting but can be earlier or later so keep an eye on the weather!

Prepare Your Containers
Use seed trays, modules, or small pots with good drainage holes and fill them with a quality seed compost that’s light and well-draining.

Sow The Seeds
Plant seeds about one centimetre deep into the compost. Place one or two seeds per cell or pot to reduce the need for thinning later. Water the compost gently and place the containers in a cool area with plenty of light. A windowsill with indirect sunlight works well. If possible, maintain a temperature between 10–15°C, as kale germinates well in cooler conditions.

Germination & Growth
Your seeds should germinate within 7–10 days. Once seedlings emerge, ensure they receive ample light to prevent them from becoming leggy. Rotate the containers daily if they lean toward the light source.

Hardening Off & Transporting
About a week before transplanting outdoors, begin to get your seedlings used to external conditions. Place them outside for a few hours each day, gradually increasing the time and exposure to direct sunlight. When seedlings are about 10–15 cm tall and have at least four true leaves, they’re ready to be transplanted. Choose a cloudy day or plant in the early evening to reduce transplant shock. Space the plants about 45 cm apart in well-prepared soil.

By following this guide on how to grow kale indoors, you set the stage for robust growth and an extended harvesting period. This method is especially useful in areas with shorter growing seasons or unpredictable spring weather.

Kale thrives in cool weather, making early spring and late summer the ideal times to plant in the UK. For a summer and autumn harvest, sow seeds from March to June as soon as the soil is workable. For a winter crop, plant seeds in June or July. Planting during these periods allows kale to grow in cooler temperatures, which promotes tender and flavourful leaves. Cooler conditions help prevent the plants from becoming tough or bitter. Kale is hardy and can withstand frost, often improving in taste after exposure to cold weather.

Learning how to plant and grow kale is a simple and rewarding process that begins with choosing the right location and preparing the soil properly.

Start by choosing a spot that enjoys full sun to partial shade and has well-draining, fertile soil. Mix in plenty of organic matter like compost or well-rotted manure to enrich the soil. Kale prefers a slightly acidic to neutral pH, ideally between 6.0 and 7.5. Before planting, clear the area of any weeds, rocks, or debris to make sure your kale has the best environment to grow.

When sowing kale seeds directly outdoors, plant them about 1 cm (0.5 inches) deep into the soil. Space the seeds or seedlings approximately 45 cm (18 inches) apart to allow plenty of room for growth and to promote good air circulation, which helps prevent disease. If you’re planting in rows, keep them about 60 cm (24 inches) apart. After planting, gently cover the seeds with soil, firm it lightly, and water thoroughly to help settle the seeds. Applying a layer of mulch can be beneficial by retaining moisture and suppressing weeds.

So that has answered the question ‘how do you plant kale’. Let’s now take a look at how you care for your plants.

Once you’ve planted your kale, there’s not much for you to do. It’s a pretty hardy plant that needs to be watered regularly when it’s young but then only really during dry weather. The seedlings need to be protected from slugs and snails and there are a few pests that can cause problems to the mature plants, including birds, whitefly and cabbage white butterflies, but on the whole they’re quite robust. Mulching helps to retain moisture and suppress weeds, making cultivation care more manageable.

If you notice an issue with caterpillars, you can cover your plants with a fleece, or insect-proof mesh. Cabbage root fly is another common problem, and this is usually countered by putting a felt cabbage collar around the bottom of the plant’s stems.

How do you harvest kale? The leaves are ready to harvest when they’re about the size of your hand, usually 70 to 80 days after planting from seed.

Time of Day
The best time to pick kale is in the morning when the leaves are crisp and full of moisture.

Pick Outer Leaves First
Start by harvesting the older, outer leaves of the plant. This encourages continuous growth from the centre, allowing the plant to keep producing new leaves. Regular harvesting every week or so can promote a longer harvesting period and more abundant yield.

Avoid Damaging the Plant
Be careful not to remove or damage the central bud at the top of the plant, as this is where new leaves will grow. Use clean, sharp scissors or a knife to cut the leaves off smoothly. This reduces stress on the plant and minimises the risk of disease.

Take Advantage of Cool Weather
Kale is one of the few vegetables that can withstand frost and cold temperatures. Because kale is hardy, you can continue harvesting into late autumn and even winter in milder regions.

Leaf Selection
Choose leaves that are firm, deeply coloured, and free from yellowing or holes caused by pests. While larger leaves are edible, they can be tougher. Younger leaves are more tender and better for fresh salads.

After Harvesting
Rinse the harvested leaves thoroughly to remove soil and any insects. Kale leaves can be stored in the refrigerator for around a week.

By following these tips, you’ll maximise your kale harvest and enjoy fresh, nutritious leaves straight from your garden.

So, we’ve explored each step of how to grow kale in the UK. Along the way, we’ve answered questions, including how do you plant kale as well as giving you some tips on its upkeep and care. Happy gardening!