Kailan (Brassica oleracea Alboglabra Group)
1 sources cited · Verified
The short answer
- Site
- 6+ hours of sun, soil pH 6–8
- Biggest risk
- Damping-off
Kailans (Brassica oleracea Alboglabra Group) — annual or biennial grown as an annual.
This crop carries an unusually heavy problem load: 1 disease, 5 pests and 0 nutrient issues are documented for it, so most of the effort in growing it well goes into prevention.
Core growing advice on this page is checked against named horticultural and university-extension sources — see References.
Diseases
Pests
Quick Facts
| Factor | Value |
|---|---|
| Soil pH | 6 - 8 |
| Sunlight | 6-6 hours direct sun |
| Soil texture | clay, loam, sand or high organic matter (NC State) |
| Drainage | good drainage |
| Lifecycle | annual or biennial grown as an annual |
| Edible parts | leaves, stems, flower buds |
At a Glance
Soil & Growing Conditions
Water: consistent moisture, good drainage (NC State)
Soil pH range
Span reflects genuine variation between the cited authorities, not a single agreed figure.
Growth Stages
| Stage | BBCH | Notes |
|---|---|---|
| Sowing | 0 | Direct sow or plant seedlings after the last spring frost; spacing 12in to 3ft depending on cultivar (NC State). |
| Leaf growth | 3 | Thick, glossy blue-green leaves develop; best growth between 64-82F, more heat-tolerant than other kales (NC State). |
| First harvest | 8 | Young leaves harvested 50-70 days after sowing (NC State). |
| Flower bud harvest | 6 | A second harvest is taken once flower buds appear; avoid delaying, as stems turn woody. Left unharvested, the flowers attract bees (NC State). |
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).
Kailan, Leaf to Harvest
References
-
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 64-82F, 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.
1 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.
Frequently Asked Questions
What soil pH do kailans need?
A pH of about 6–8. That span reflects genuine variation between the authorities we cite rather than a single agreed figure — the References section lists each source's exact range.
What problems affect kailans?
Our data links 1 disease and 5 pests to this crop. See the sections above for each one and how to manage it.
Plan next season before the problems start
Almost everything on this page resolves to your own frost dates rather than the calendar — the last spring frost moves by roughly two months between zone 3 and zone 10. The USA Garden Planner works from your zone so the timing is already decided before the season starts.
Get the USA Garden Planner →Instant PDF download · Written for US growing conditions
Last verified 2026-08-29
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.