Kale Growing Guide
Kale is a popular and nutritious leafy vegetable from the cabbage (brassica) family, renowned for its ease of growth, productivity, and ornamental qualities. It is one of the hardiest leafy vegetables, providing fresh leaves even during the coldest months. Plants can grow up to 90cm tall, with varieties offering smooth, puckered, or frilly leaves in green or purple-red shades. It can be harvested as tender baby salad leaves or as mature greens for cooking and smoothies, with harvesting possible from autumn through spring, and regular picking encouraging further growth.
This guidance applies to the crop in general. Individual varieties and local conditions can differ.
Planting information
Sow seeds indoors from March to get an early start, or outdoors from March to June. For indoor sowing, fill modular trays with peat-free multi-purpose compost, water, and make a 1cm deep hole in each module. Sow two seeds per hole, cover with compost, and remove the weaker seedling if both germinate. Keep in bright light and water regularly. For microgreens, sow seeds into a small seed tray of damp peat-free seed compost, water regularly. For outdoor sowing, prepare the site by weeding and firming the soil. Make a shallow drill about 1cm deep. If using a seedbed, sow seeds thinly 10-15cm apart, or thin seedlings to this spacing. If sowing in the final position, sow three seeds approximately every 45cm along the drill, then thin to one seedling after germination. For large varieties, sow 60cm apart; for compact varieties, 30cm apart. Space rows at least 45cm apart. For salad crops, sow direct into their final position, spacing seeds about 7.5cm apart, sowing little and often for a continuous supply. For container growing of salad plants, scatter seeds thinly, cover with 1cm compost, and water well. For mature compact varieties in containers, sow three seeds every 30cm, then thin to one strong seedling. Move young kale plants to their final growing position in late spring or early summer when they are 10-15cm tall. Harden off indoor-sown plants beforehand. Carefully lift each plant or remove from the modular tray, minimizing root disturbance. Set them into new planting holes deeper than before, with the lowest leaves at the soil surface to encourage deep rooting. Firm each plant in and water well. For mature plants, space them 30-60cm apart, depending on the variety, ensuring wide spacing for light, air, and disease deterrence. For baby-leaf salad crops, spacing can be much closer, about 7.5cm apart. Protect young plants from slugs, snails, insects, and birds by covering with fine-mesh netting. For container planting of baby-leaf salad, plant young kales about 7.5cm apart. For mature compact varieties in containers, use a pot at least 30cm wide and deep for one plant, using peat-free multi-purpose compost and planting deeply. Position the container in a sunny spot and keep it well-watered.
Harvesting information
Kale is typically ready to harvest from September onwards. Pick two or three of the lower leaves from each plant at a time. When growing as a cut-and-come-again salad crop, begin harvesting as soon as plants reach 10-15cm tall. You can either pick individual leaves from several plants or cut the entire rosette of leaves from a single plant; the latter method will allow the plant to re-sprout for a subsequent crop.