How to Grow Kailans UK

When to Plant Kailans in the UK

When to plant kailans in the UK: in Southern England, sow early April to early July. Find your area in the table below.

Quick Facts

At a Glance

Soil & Growing Conditions

Water: consistent moisture, good drainage (NC State)

Growth Stages

Harvest & Storage

When to pick: Young leaves harvested 50-70 days after sowing, and again once flower buds appear. Avoid harvesting too late, as the stems become woody (NC State).

Diseases

Pests

Kailan, Leaf to Harvest

Its own recognised cultivar group

Kailan sits in the Alboglabra Group of Brassica oleracea -- the same species as the site's Broccoli and Cauliflower, but its own named group, taken from the Latin for "white and smooth," describing its flowers and leaves.

Leafier and thicker-stemmed than broccoli

NC State Extension: thick, glossy blue-green leaves on a leafier, thicker-stemmed plant than ordinary broccoli, reaching 1-2ft tall.

More heat-tolerant than other kales

NC State Extension: best grown between 64-82°F, tolerating summer heat better than other kales -- a practical advantage in warmer growing regions.

Two harvests from one planting

Young leaves are picked 50-70 days after sowing, and again once flower buds like these appear -- but not much later, or the stems turn woody (NC State Extension).

Stem, leaves and buds together

The whole leafy stem is harvested and eaten, not just the florets -- the thicker stem is a defining feature that separates kailan from ordinary broccoli at the table.

References

1. NC State Extension - Brassica oleracea Kai Lan & Chinese Kale Group (Chinese Broccoli, Chinese Kale, Gai Laan, Kai Lan)

   Height 1-2ft, width 1-1.5ft. Full sun (6+ hours) or partial shade (2-6 hours). Soil: clay, loam, sand or high organic matter; neutral pH 6.0-8.0; good drainage with consistent moisture. Best grown between 64-82°F, tolerates summer heat better than other kales. Direct sown or planted as seedlings; in North Carolina, plant after the last frost in spring. Spacing 12in to 3ft depending on cultivar. Thick, glossy blue-green young leaves harvested in 50-70 days, and again once flower buds appear; avoid harvesting too late to prevent woody texture. PESTS: flea beetles, diamondback moth, borers, cabbage looper, aphids, grasshoppers, crickets. DISEASES: damping-off is the primary concern; good drainage helps keep this disease at bay. Suitable for coastal, piedmont and mountain regions of NC. Pesticide spraying not recommended for edible plants; flowers attract bees.

2. Royal Horticultural Society - How to grow Chinese Broccoli

   Sow from mid-spring onwards indoors, or outdoors between April and September, 2cm deep. Thin to 10-15cm apart for baby leaves or 30cm for full-sized plants, rows 30cm apart. Wants rich, moisture-retentive but well-drained soil in full sun, with organic matter worked in and pH kept up, as the crop is susceptible to CLUB ROOT on acid soils. Young salad leaves ready in as little as three weeks; florets after about ten weeks once plants reach roughly 40cm tall. HARVEST by cutting the top few centimetres with a knife JUST BEFORE the first white flowers open -- the more you harvest, the more it produces. Does not reliably regrow after winter without protection. Pests and diseases: club root, cabbage caterpillars, cabbage root fly, cabbage whitefly, flea beetles, mealy cabbage aphid, white blister, slugs and snails.

2 independent sources are cited for this crop. Where they disagree - soil pH is the clearest case - every figure is preserved rather than averaged into false precision.