Kale, also known as Borecole, is easier to grow than other brassicas and can withstand cold weather and less fertile soil. Classified as a superfood, kale has become increasingly popular and comes in flat-leaf and curly-leaf varieties.
Kale is preferably sown directly in position, particularly flat-leafed varieties, as they do not like being transported. Curly-leafed varieties can be started in pots, but they can grow quite large, so it’s worth bearing this in mind.
Kale is a fairly low-maintenance crop and it can be sown in light shade. If you’re wondering when to plant kale, March to June is an ideal time to sow them.
Sow the kale seeds approximately half a metre apart and about 1cm deep. Ideally, protect the kale from slugs and keep the soil weed-free until the plant is established. Once it grows large, it will shade and prevent any weed growth as long as it receives consistent watering during dry spells.
You can plant out pots of curly-leafed kale once they are big enough, and thin as necessary. The young leaves are great in salads!
From later in autumn, throughout the winter into early the following spring, you will be able to harvest the leaves. Pick young leaves from the crown first to encourage side shoots. Larger, more mature leaves can be bitter.
Crispy Kale is a great healthy snack, and you can check out the recipe here.
To grow kale, you must start by choosing a spot with open soil and steady light, where plants have space to spread as they mature. Kale grows best when you sow seeds directly into the ground, since the roots settle more comfortably without disturbance.
Flat-leaf types prefer this approach, while curly-leaf varieties also cope well if you start them in pots and move them outside later.
A significant part of growing kale involves ensuring a lightly moist soil to support steady growth. Regularly checking for pests and providing gentle care also helps the plant focus its energy on producing strong, healthy leaves over time.
Growing kale in the UK depends on how you want the plant to grow and when you plan to harvest. Kale seeds are usually sown in spring, once the soil has warmed and become workable.
For direct sowing, wait until the risk of frost has passed, as early chill can slow early development. If you prefer a more controlled start, you can sow seeds in small pots and move them outside once the plants are strong enough to handle more variable conditions.
Sowing later is also recommended if you want kale leaves during the cooler months. Spacing your sowing dates helps maintain a steady supply and keeps your plants healthy throughout the growing season.
Spacing plays a significant role in how well the plants develop over time. Aim to leave around 45 to 60 centimetres between each plant so air can move freely and leaves can expand without overcrowding.
Kale benefits from soil that stays consistently moist, especially during dry periods. Therefore, water deeply once or twice a week, depending on rainfall, and focus on the base of the plant rather than the leaves.
Keep the area around young plants clear, as weeds compete for moisture during the first 4 to 6 weeks. As the plants grow taller, their leaves begin to shade the soil, naturally limiting further weed growth.
If you’re deciding when to pick kale, you can begin harvesting once the plants have formed many full-sized leaves. This usually happens 6 to 8 weeks after sowing, once the plant has had time to settle and grow steadily.
Pick leaves regularly rather than all at once, as this encourages fresh shoots to form over time. Aim to harvest in dry conditions, since wet leaves are more likely to bruise during handling. Younger leaves tend to have a softer texture, while older leaves benefit from cooking before use.
As temperatures drop, kale continues to grow slowly, making it a reliable crop to harvest over a longer period.
Want to make the most of your kale harvest and enjoy nutrient-rich leaves all season? At Allotment Online, we provide detailed growing guides, crop-specific tips and practical advice tailored to help your crops thrive from sowing to harvest.
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If you’re looking for guidance on other crops, explore our Grow Your Own page to discover tips for apples, blueberries, courgettes and more!