How to Grow Kale

Overview

Kale is one of the hardiest vegetables you can grow, providing fresh, nutritious leaves from autumn through to spring when little else is available. It is packed with vitamins and minerals and comes in a range of attractive varieties, from curly to cavolo nero. Kale actually tastes sweeter after a frost.

Health Benefits

Exceptionally rich in Vitamins A, C, and K: A single serving of kale can provide several times your daily need for Vitamins K and A, along with a generous dose of Vitamin C.

Calcium for bone health: Kale is one of the best plant-based sources of calcium, and the calcium in kale is more easily absorbed than that from some other vegetables.

Loaded with antioxidants: Kale contains quercetin, kaempferol, and other antioxidants that may help reduce inflammation. It is widely considered one of the most nutritious vegetables on the planet.

Soil Preparation

Kale grows best in firm, fertile soil that has been enriched with well-rotted compost. It tolerates most soil types but prefers a pH of 6.5 to 7.0. Firm the soil well before planting, as loose soil can cause leggy, unstable plants. Brassicas benefit from the residual fertility left by a previous legume crop.

Sowing & Planting

Sow seeds in a seedbed or modules from April to June, 2cm deep. Transplant seedlings to their final positions when they have 4-5 true leaves, spacing 45cm apart in rows 60cm apart. Water well after transplanting and firm the soil around the stems. Net immediately to protect from pigeons and cabbage white butterflies.

Care & Maintenance

Water regularly during dry spells, especially while plants are establishing. Feed with a nitrogen-rich fertiliser in late summer to boost winter leaf production. Earth up around the stems in autumn to provide extra stability in winter winds. Remove yellowing lower leaves to improve air circulation.

Harvesting

Begin picking young leaves from September onwards, taking a few from each plant rather than stripping them bare. Kale will continue producing new leaves from the crown through winter and into early spring. The flavour improves markedly after exposure to frost, which converts starches to sugars.

Common Problems

Cabbage white butterfly caterpillars can strip leaves quickly. Cover with butterfly netting and check regularly for eggs on the undersides of leaves.

Whitefly can congregate on the undersides of leaves in mild winters. Spray with soapy water or use yellow sticky traps.

Club root causes swollen, distorted roots and stunted growth. Lime acidic soil and practise crop rotation to reduce risk.

Companion Planting

Kale benefits from being grown near beans, beetroot, and celery, which help improve soil fertility and deter pests. Avoid planting near strawberries, which can compete for nutrients.