How to Grow Kohlrabis
On this page
Kohlrabi seed germinates within two weeks once soil temperatures warm above 10°C. Harvest the swollen stem while young, between golf-ball and tennis-ball size (5–6cm diameter) — larger stems turn woody and lose flavour, especially in hot, dry weather.
The short answer
- Ready in
- 42–84 days
- Site
- soil pH 6–6.5
- Biggest risk
- Brassica downy mildew
Core growing advice on this page is checked against named horticultural sources — see References.
Kohlrabi (Brassica oleracea Gongylodes Group)
12 sources cited · Verified
Quick Facts
At a Glance
Diseases
Pests
Soil & Growing Conditions
Growth Stages
Harvest & Storage
Kohlrabi, a Fast Above-Ground Cabbage-Family Globe
Plan your Kohlrabis planting
Timing for Kohlrabis follows soil temperature and frost, not the calendar date. The Global vegetable planting calendar explains the method. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.
Growing Kohlrabi in another region
Sowing dates, frost timing and local advice differ by country. Use the guide for where you garden.
Sources
These source is specific to this region. The full list of 12 sources behind this guide (Clemson Cooperative Extension, FAO EcoCrop, Royal Horticultural Society and others) is in the references of our UK guide to kohlrabi; they describe the plant itself, which is the same wherever it grows.
Frequently Asked Questions
How long does kohlrabi take to grow?
Typically 42–84 days, depending on cultivar and growing conditions.
What soil pH does kohlrabi need?
A pH of about 6–6.5. 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 kohlrabi?
Our data links 3 diseases 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
This page gives you the thresholds; the planner turns them into your own calendar. It works from what you can observe and measure in your garden rather than from dates written for somebody else’s latitude.
Get the Global Garden Planner →Instant PDF download · Works in either hemisphere
How this guide is put together
The growing data on this page — sowing windows, pests, diseases, soil and site requirements — comes from named horticultural sources, listed in References below, checked against international horticultural research and extension sources. An automated pipeline assembles that verified data into the page you're reading: it selects which facts to lead with and builds the surrounding prose and layout. It does not invent a date, a source or a number — where a verified value for a field isn't available, the page leaves it out rather than guessing. A person reviews and publishes each page; nothing goes live unverified.
Related Problem Guides
Last verified 2026-09-02
Related guides
More from the same group (brassicas & mustards):
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Keep going
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.